Abstract
This chapter describes the different types of cutaneous myelomonocytic infiltrates. The disease presentation, associated disorders, cutaneous findings, and pathological features are discussed. Further, treatment options of these rare disorders are highlighted, and immunophenotypical information is highlighted to show how to differentiate each of these clinical similar entities. Tables summarizing key clinical findings and pathological features along with histological figures will aid the reader in developing a better understanding for the diagnosis and treatment of these rare disorders.
Access provided by Autonomous University of Puebla. Download chapter PDF
Similar content being viewed by others
Keywords
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.
Introduction
Although extremely rare, myelomonocytic infiltrates can be found on the skin. Distinguishing different types is important since these infiltrates vary from benign to malignant in nature. Myelomonocytic skin lesions may be the first signs of a systemic disease amenable to systemic therapy or may be localized lesions that can be controlled with skin-directed therapy (Haniffa et al. 2006). Clinical features, cytomorphology, and immunophenotype are all important facets helpful in differentiating these disorders. In this chapter, the different myelomonocytic cutaneous infiltrates including cutaneous extramedullary hematopoiesis, cutaneous myelomonocytic infiltrates in patients with myelodysplastic syndrome (MDS)/myeloproliferative disorders (MPD), myeloid sarcoma, blastic plasmacytoid dendritic cell neoplasm (BPDCN), dendritic cell infiltrates, and histiocytic infiltrates are reviewed in detail. Table 16.1 highlights the cutaneous findings and epidemiology of the different myelomonocytic subtypes, and Table 16.2 outlines the immunophenotypical findings.
Cutaneous Extramedullary Hematopoiesis
Extramedullary hematopoiesis (EMH) is a common finding among patients with myeloid malignancies and hemoglobinopathies (Korsten et al. 1970; Glew et al. 1973; Rice et al. 1980; Lewkow and Shah 1984; Gowitt and Zaatari 1985; Gumbs et al. 1987; Shih et al. 1988; de Morais et al. 1996; Dibbern et al. 1997) or due to compromise of normal marrow space from foreign cells, cytokine-driven myeloid expansion, or stromal fibrosis (O’Malley 2007).
Definition
Cutaneous extramedullary hematopoiesis (CEMH) is defined as involvement of the skin with precursor hematopoietic tissue, which is normally in the bone marrow. The usual EMH sites include the liver and spleen, but almost all anatomical body locations can be affected including the skin (Koch et al. 2003; Pitcock et al. 1962; Mizoguchi et al. 1990). EMH is essential in fetal life, but after birth it is usually considered an abnormality (Koch et al. 2003). In a series of 510 patients with EMH, there were 27 patients (5.3 %) who were diagnosed with nonhepatosplenic EMH, and out of these, two patients had cutaneous EMH (Koch et al. 2003).
Epidemiology
The most common underlying condition associated with EMH is primary myelofibrosis. Little is known about the exact etiology of CEMH because of its rarity, with most information coming from case reports or small series. Large series from three reports of 220 patients with myelofibrosis reported only one with CEMH (Bouroncle and Doan 1962; Pitcock et al. 1962; Ward and Block 1971). Literature documentation of CEMH comprises a total of about 30 cases and appears to be most frequently associated with myelofibrosis or myeloproliferative disorders (Patel et al. 1995; Revenga et al. 2000; Fernandez Acenero et al. 2003). Increased levels of transforming growth factor-beta appear to be associated with CEMH in patients with idiopathic myelofibrosis (Collie et al. 2013; Corella et al. 2008; Haniffa et al. 2006; Kawakami et al. 2008; Kwon et al. 1999; Lane et al. 2002; Miyata et al. 2008; Mizoguchi et al. 1990; Pagerols et al. 1998; Rodriguez et al. 1991; Rogalski et al. 2002; Ruberto et al. 1995).
Clinical Appearance of Cutaneous Lesions
Lesions presented as firm nodules in dermis and subcutaneous tissue. Pink, reddish, or bluish plaques, papules, or nodules are commonly seen and hemorrhage can develop around the lesion (Mizoguchi et al. 1990).
Pattern of Infiltration
Infiltrates are perivascular and may be limited to the dermis and subcutaneous tissue without epidermotropism.
Cytomorphology
Hematopoietic cells of different lineages and admixture could be seen. These include myeloid precursor cells in several stages of maturation, nucleated erythroid precursors, and mature megakaryocytes (Haniffa et al. 2006) (see Fig. 16.1). The presence of pure myeloid or erythroid precursors is rare, and in those cases with immature cells or blasts, a diagnosis of myeloid sarcoma should be ruled out (Mizoguchi et al. 1990).
Extramedullary myeloid infiltrate in a child post-chemotherapy, (arrows) point to immature erythroid precursors and (stars) note the multinucleated megakaryocytes
Clinical Behavior
The prognosis in patients with nonhepatosplenic EMH is based on the underlying etiology. Hence, finding a cutaneous EMH should prompt a process for finding a systemic cause or even performing a bone marrow biopsy and a hematology consult. As a group, nonhepatosplenic EMH have poor outcome with the median survival of 13 months (Koch et al. 2003). Treatment is based on treating the underlying disorder, most commonly primary myelofibrosis.
Differential Diagnosis
CEMH is a type of infiltrative process in the “cutis” and is seen in patients with an underlying marrow disorder or even acute leukemia, and a bone marrow biopsy should be done in patients with isolated CEMH. Myeloid sarcoma with differentiated cells can also mimic CEMH, and immunohistochemistry for myeloid-monocytic markers such as CD43, lysozyme, CD68, and stem cell markers CD34 or CD117 may separate the immature from mature extramedullary hematopoiesis (Porcu et al. 1999). In general, a CD3-negative and CD43-positive immature single-field dermal infiltrate suggests a myeloid sarcoma instead of T-cell lymphoma.
Cutaneous Myelomonocytic Infiltrate in Patients with MDS/MPD
Introduction
Common myelomonocytic infiltrations under the generic nonspecific term “leukemia cutis” and more specifically myeloid sarcoma have been observed in patients with cutaneous lesions (List et al. 1991). Patients with an underlying myeloid disorder can develop specific (clonal, malignant) or nonspecific (reactive, benign) cutaneous lesions (Bluefarb and Webster 1953; Wong et al. 1995). Lesions that are specific are those in which the skin is involved by myelomonocytic leukemic cells and show histological changes compatible with leukemia cutis (LC). Nonspecific lesions include leukemoid reactions that may be due to bacterial, viral, and fungal infections secondary to immunosuppression or a hemorrhagic diathesis resulting in petechiae or purpura (Wong et al. 1995). Another subset of patients can developed neutrophilic infiltrates of the skin such as seen in pyoderma gangrenosum, bullous pyoderma, and Sweet’s syndrome (Burton 1980) (see Chap. 15 for discussion on pyoderma gangrenosum and Sweet’s syndrome). This chapter focuses the discussion on LC.
Definition
Cutaneous infiltrates that have similar histopathologic findings to the clonal underlying hematopoietic disorder are characterized as leukemia cutis (LC). LC is a clinical term applied to tumors in skin associated with underlying primary bone marrow neoplasms which could include mature and immature leukemia such as chronic lymphocytic leukemia, precursor lymphoblastic/leukemia, and acute to chronic myelomonocytic leukemia (Su 1994; Kumar 1997; Burns et al. 2005; Kaune et al. 2009; Lee et al. 2010; Wagner et al. 2012). LC discussion in this section is limited to those infiltrates that are histopathologically of myelomonocytic in origin.
Epidemiology
LC has been well described in patients with acute myelogenous leukemia but has rarely been associated with MDS or MPD. In one series of 44 cases of LC, 41 cases were related to myeloid leukemia and 2 to MDS, and 1 was related to polycythemia vera (Wong et al. 1995).
Clinical Appearance of Cutaneous Lesions
Lesions can be located anywhere on the body and can appear as either solitary or multiple purpuric papules or plaques. They can also be ulcerated or non-ulcerated nodules or subcutaneous masses. The most common anatomical location is the lower extremities, followed by the upper extremities, back, trunk, and face (Paydas and Zorludemir 2000).
Pattern of Infiltration
Dense and diffuse cellular infiltrate occupying the dermis and extending into the subcutaneous tissue is seen (Wong et al. 1995). In 18 of 44 cases of nonlymphocytic leukemias (mostly acute myeloid leukemia, two MDS, and a polycythemia vera), sparing of the grenz zone was observed. Infiltration of the nerves as well as the hair follicles, sebaceous glands, sweat glands, and vessels with a prominent “Indian filing”; perivascular targetoid pattern; or single-cell filing pattern of immature blast forms was also seen. Some infiltrates also involved exclusively the subcutaneous fat. Less common patterns include kaposiform-like and neutrophilic infiltrates with scattered blasts (8 of 52 cases), and atypical immature myeloid cells with a predominately perivascular pattern with associated MDS (Wong et al. 1995).
Cytomorphology
Morphology is similar to the primary myeloid neoplasm and shows dysplastic cells in those with an underlying myelodysplastic syndrome or myeloproliferative syndrome. At higher power, these cells can show variable cytological differentiation and marked pleomorphism and can stain positive for chloroacetate esterase or Leder stain if myelomonocytic in origin. Periodic acid-Schiff (PAS) stains most lymphoblasts in a dot pattern.
Depending on tumor cell differentiation, a blastic (undifferentiated) or maturing (differentiated) morphology could be seen. Blastic pattern shows monomorphous infiltrate of blasts. Neoplastic, neutrophilic, or eosinophilic precursors could be seen in differentiated forms (see Fig. 16.2a). Round myeloblasts admixed with myelocytes with nuclear folds are the rule in acute myeloid leukemia and in chronic myeloid leukemia (CML) and other myeloproliferative/MDS disorders. The morphologic hallmark is a maturing leukemic cellular pattern of myeloblasts, eosinophilic myelocytes, bands, and neutrophils that mimic the marrow appearance of CML. In acute monocytic leukemia, deeply folded grooved or kidney-shaped vesicular nuclei, positive for nonspecific esterase but negative for Leder stain, are the typical picture.
(a) Myeloid sarcoma from a patient with a myeloproliferative neoplasm with eosinophilic differentiation. Note the cytoplasmic eosinophilic granules in some dysplastic eosinophils and immature cells. (b) Chronic lymphocytic leukemia/lymphoma involving skin with prolymphocytes (inset) CD20 (inset2) CD5 and (c) CD23 positivity
Immunophenotype
Immunophenotypical markers corresponding to the primary underlying myeloid neoplasm are observed. Most myeloid sarcoma should stain with CD43, lysozyme, and myeloperoxidase (MPO). MPO staining may be absent in monocytic LC (Cho-Vega et al. 2008).
Cytogenetic/Molecular Findings
LC is seen commonly in patients with acute myeloid leukemia with trisomy of chromosome 8 (Sen et al. 2000; Agis et al. 2002; Pileri et al. 2007). Tetrasomy and pentasomy of chromosome 8 have been reported as well (Ferrara et al. 1996; Gould et al. 2000).
Clinical Behavior
Patients with LC follow a clinical course similar to that of the underlying disease.
Differential Diagnosis
Myeloid sarcoma and Langerhans cell histiocytosis should be ruled out in patients with LC. Myeloid sarcoma can present as a type of leukemia cutis but can be differentiated from mature lymphocytic and lymphoblastic forms based on morphology, clinical history, and immunohistochemical profiling (see text on myeloid sarcoma). Most precursor B lymphoblasts should stain with CD79a, TDT, or CD10 with precursor T blast staining with cytoplasmic CD3 instead. Mature lymphocytic leukemia will mark with corresponding markers for chronic lymphocytic leukemia/lymphoma (CLL): CD23, CD5, and CD20 (see Fig. 16.2b).
Myeloid or Granulocytic Sarcoma
The skin is one of the most common sites of involvement of myeloid sarcoma (MS). The mechanism by which myeloid blasts migrate to the skin is poorly understood, but it may be due to the expression of chemokine receptors and adhesion molecules by the blasts and the various cell types residing in the skin (Cho-Vega et al. 2008).
Definition
A myeloid sarcoma is by definition a tumor mass that is composed of myeloid blasts with or without maturation occurring at any anatomical site other than the bone marrow and resulting in an effacement of underlying tissue architecture. The lesion was first described by Burns in 1811 (Burns 1811). In 1853 the term “chloroma” was given to the lesion because such tumors often display a greenish color that fades on exposure to air due to the presence of myeloperoxidase (King 1853). MS is also known as a granulocytic sarcoma, chloroma, or extramedullary myeloid cell tumor (Rappaport 1966). MS is included in the 2008 WHO classification of myeloid neoplasm as distinct manifestation of acute myeloid leukemia (Swerdlow et al.2008). Patients with known myeloid leukemia infiltrates of any site of the body by myeloid blasts are not classified as MS unless the tumor effaces the tissue architecture. Skin, lymph node, gastrointestinal tract, bone, soft tissue, and testis are the most frequently affected sites (Falini et al. 2007; Pileri et al. 2007). Rarely, multiple anatomical sites are affected in a single patient.
Epidemiology
MS has been reported in 2.5–9.1 % of patients with AML and can occur concomitantly, following, or prior to systemic bone marrow leukemia (Wiernik and Serpick 1970; Liu et al. 1973; Krause 1979; Neiman et al. 1981). Males are more affected than females with a ratio of 1.2:1. Median age is 56 years but is also seen in older patients (Falini et al. 2007; Pileri et al. 2007; Hurley et al. 2013). In one series of 61 biopsied cases, 13 had skin involvement (Neiman et al. 1981). Incidence of MS after allogeneic hematopoietic cell transplantation has been reported to be 0.2–1.3 % with poor overall survival (Bekassy et al. 1996; Szomor et al. 1997).
Clinical Appearance of Cutaneous Lesions
Multiple skin lesions such as papules, plaques, and/or nodules are commonly described. The torso is more commonly involved, but one study did favor the involvement of the upper body (Hurley et al. 2013).
Pattern of Infiltration
Pleomorphic blasts are seen in the dermis and subcutaneous tissue.
Cytomorphology
Blasts are identifiable by their immature cytomorphology with dispersed nuclear chromatin with nucleoli and abundant mitotic activity with scattered apoptotic cells (Liu et al. 1973; Krause 1979; Neiman et al. 1981; Eshghabadi et al. 1986; Meis et al. 1986). Eosinophilic myelocytes can also been seen (Lin et al. 1990). Myelomonocytic or pure monoblastic morphology can be seen (Falini et al. 2007; Pileri et al. 2007) (see Fig. 16.3).
Myeloid sarcoma without differentiation (blastic form). Note the atypical blasts with open vesicular and dispersed chromatin
Immunophenotype
CD68/KP1 is the most commonly expressed marker followed by MPO, CD117, CD99, lysozyme, CD34, TdT, CD56, CD61, CD30, and CD4 (Pileri et al. 2007). In one series lysozyme was positive in all cases, with myeloperoxidase in 56 %, CD68 in 100 %, and CD34 in 19 % of patients (Hurley et al. 2013). Cases can demonstrate aberrant expression of T- or B-cell lineages which can lead to an erroneous diagnosis (Hanson et al. 1993).
Cytogenetic/Molecular Findings
Chromosomal aberrations by FISH or cytogenetics are detectable in 55 % of cases (Pileri et al. 2007). Monosomy 7; MLL (myeloid/lymphoid or mixed-lineage leukemia) rearrangement; trisomy 4; monosomy 16, 16q, 5q, and 20q; and trisomy 11 are some of the reported abnormalities (Pileri et al. 2007). Trisomy of chromosome 8 and inversion 16 are more common in MS involving the skin (Dachary et al. 1986; Cronin et al. 2009; Hurley et al. 2013). NPM1 mutations are seen in 16 % of cases (Falini et al. 2005, 2007).
Clinical Behavior
Prognosis is poor in patients with MS. MS is considered an equivalent of a diagnosis of acute myeloid leukemia and should be treated with induction chemotherapy (Eshghabadi et al. 1986; Lin et al. 1990). Allogeneic hematopoietic cell transplantation carries a higher probability of prolonged survival or cure (Breccia et al. 2004; Pileri et al. 2007). Radiation therapy can be useful in emergency or palliative settings (Bakst et al. 2012).
Differential Diagnosis
T- and B-cell malignancies especially non-Hodgkin lymphoma can be differentiated by cytomorphology and immunohistochemistry (46 % of cases in one series) (Byrd et al. 1995). Lymphoblastic leukemia, melanoma, Ewing’s sarcoma, blastic plasmacytoid dendritic cell neoplasm (see section on BPDCN below), and immature EMH should be considered as well (Ngu et al. 2001).
Blastic Plasmacytoid Dendritic Cell Neoplasm (BPDCN)
Definition
BPDCN is an aggressive tumor derived from the precursors of plasmacytoid dendritic cells. BPDCNs have myeloid ancestors in common with monocytes and are found in the bone marrow and skin (Liu et al. 2009). BPDCN was previously known as blastic NK-cell lymphoma, CD4 + CD56+ hematodermic neoplasm, and plasmacytic dendritic cell leukemia, making it difficult to track historically (Lim et al. 2013). Cutaneous findings are seen universally in BPDCN and 50 % of patients present with isolated cutaneous lesions (Cota et al. 2010).
Epidemiology
BPDCN is a very rare neoplasm representing approximately 0.8 % of the primary cutaneous lymphomas (Petrella and Facchetti 2010). There is a 3.3:1 male/female ratio with most patients being elderly with a mean age at diagnosis of 61 years. Though it usually occurs in the elderly, it can occur in children and has been reported in patients as young as 8 years of age (Lim et al. 2013). There is no increased incidence in any one ethnic group (Feuillard et al. 2002; Jacob et al. 2003; Herling and Jones 2007).
Clinical Appearance of Cutaneous Lesions
Patients usually present with asymptomatic brownish to violaceous nodules, plaques, or bruise-like areas which can be solitary or in multiple locations on the skin (Feuillard et al. 2002; Julia et al. 2013; Lim et al. 2013). In one study 73 % of patients had nodular lesions only and 12 % had bruise-like patches, while 15 % had disseminated and mixed lesions (Julia et al. 2013). Twenty percent of patients will have regional lymphadenopathy (Lim et al. 2013).
Pattern of Infiltration
BPDCN is characterized by a diffuse, monomorphous infiltrate of medium-sized blast cells with irregular nuclei, fine chromatin, and one to several small nucleoli. Tumor cells occupy the dermis and spare the epidermis but will eventually invade the subcutaneous fat (Petrella et al. 1999, 2005; Cota et al. 2010).
Cytomorphology
A plasmacytoid cytological appearance is seen in medium- to high-power view, but these cells usually lack a perinuclear hof of true plasma cells (see Fig. 16.4). The cells are derived from plasmacytoid dendritic cells, an antigen presenting cell, resident in skin and lymph nodes. Cytoplasm is usually scant to moderate, may be eccentric, and appears gray blue and agranular on Giemsa stain. Mitoses are rarely prominent and angioinvasion is rare. BPDCN is negative with nonspecific esterase and myeloperoxidase cytochemical stains.
Blastic plasmacytoid dendritic cell leukemia involving the skin. (a) Subepidermal plasmacytoid blasts with single-cell pattern. (b) Targetoid perivascular pattern
Immunophenotype
BPDCN cells are positive for CD4, CD56, CD123, and TCL1 (Tecchio et al. 2009; Cota et al. 2010). Rarely CD56 can be negative, but if CD4, CD123, and TCL1 are present, this does not exclude the diagnosis. Occasionally CD7, CD33, CD43, CD45RA, TL1-A, and HLA-DR can be positive. Most tumors lack conventional myeloid and lymphoid T- and B-cell antigens (Petrella et al. 1999, 2002; Herling et al. 2003; Petrella et al. 2004, 2005; Reichard et al. 2005; Willemze et al. 2005; Assaf et al. 2007; Herling and Jones 2007; Pilichowska et al. 2007; Garnache-Ottou et al. 2009). Newer markers that can be diagnostic include CD2AP (Marafioti et al. 2008), BDCA-2 (CD303), and BDCA-4 (CD304) (Garnache-Ottou et al. 2009). CD68 is expressed in 50 % of cases as small cytoplasmic dots (Petrella et al. 2004, 2005).
Cytogenetic/Molecular Findings
Cytogenetic analysis often shows a complex karyotype (Feuillard et al. 2002; Petrella et al. 2005; Herling and Jones 2007; Ascani et al. 2008; Garnache-Ottou et al. 2009) or deletions of tumor suppressor genes in the majority of cases (Jardin et al. 2009). Genomic losses affecting 5q21 or 5q34, 12p13, 13q21, 6q23, 15q, and chromosome 9 have been reported (Petrella et al. 1999; Leroux et al. 2002; Reichard et al. 2005; Guo et al. 2011; Lucioni et al. 2011; Julia et al. 2013). A recent study suggested that a mutation of CDKN2A/CDKN2B on chromosome 9 could help identify more aggressive cases (Lucioni et al. 2011). One study showed that IgH and TCR-gamma gene rearrangement analysis done in 34 biopsies from 27 patients showed a polyclonal smear in all cases (Cota et al. 2010).
Clinical Behavior
The majority of patients present with asymptomatic solitary or multiple skin lesions usually with nodules and plaques. Low-level bone marrow involvement is often seen at presentation or soon after (Feuillard et al. 2002; Herling and Jones 2007; Ascani et al. 2008; Garnache-Ottou et al. 2009). Leukemic dissemination is part of the natural progression of the disease and can be present before, at the same time with, or after skin lesions (Julia et al. 2013). In one series 61 % of patients had bone marrow, lymph node, and/or blood involvement (Julia et al. 2013). Lymphadenopathy and/or splenomegaly are common. Overall prognosis is poor with medial overall survival duration of 12–14 months (Feuillard et al. 2002; Lim et al. 2013). Increased age predicts a worse prognosis. Patients with skin involvement only have initially less aggressive course and can benefit from skin-directed therapy or steroids (Pileri et al. 2012). This approach is especially useful in older patients or younger patients with multiple comorbidities who are not eligible for systemic intensive chemotherapy or allogeneic stem cell transplant. Treatment with radiation therapy and chemotherapy has been used with varying success in patients with BPDCN. Radiation therapy can achieve a complete response in 80 % of patients with localized disease but is associated with a short time to relapse, with a mean of 5.5 months (Dalle et al. 2010). Combined chemotherapy regimens have been given with varying success including cyclophosphamide, doxorubicin, vincristine, prednisone (CHOP-like), or cytarabine-based treatments. Complete responses have been documented in 50–75 % of patients, but relapses usually occur within months and chemotherapy resistance develops (Ng et al. 2006; Dalle et al. 2010). Recently, the incorporation of L-asparaginase in chemotherapy regimen showed promising results (Gruson et al. 2013). Skin findings are almost always present at relapse. In elderly patients who are not a candidate for systemic therapy, skin lesions can respond to monotherapy with steroids. Allogeneic stem cell transplantation is the only known curative approach with mean survival of 31 months. It should be considered in younger patients who achieve complete remission with induction chemotherapy (Reimer et al. 2003; Dalle et al. 2010).
Differential Diagnosis
Skin localizations of myelomonocytic disorders and MS would have overlapping immunohistologic findings, but a CD56, CD4, and CD123 positive blastic skin leukemic infiltrate with plasmacytoid cytomorphology would favor a BPDCN. Extranodal natural killer/T-cell nasal-type tumors and PTCL-unspecified and pleomorphic T-cell lymphomas can be ruled out with immunohistochemistry and cytomorphology with EBV + favoring extranodal NK cell and T cells that are CD30- and CD68-negative T-cell infiltrate, favoring the two latter entities (Petrella et al. 2005).
Interdigitating Dendritic Cell Sarcoma (IDCS)
Definition
Interdigitating dendritic cells present antigens to T cells and regulate cellular immune response (Steinman et al. 1997; Imai et al. 1998; Steinman 2003; Chung et al. 2004; Maeda et al. 2005; Saygin et al. 2013). These cells originate from hematopoietic precursors through the conversion of Langerhans cells as they travel to the lymph node and from the differentiation of myeloid and lymphoid precursor cells (Wood et al. 1985; Rosenzweig et al. 1996; Steinman et al. 1997; Wu and Liu 2007; Saygin et al. 2013). IDCS is a malignant disorder of interdigitating dendritic cells.
Epidemiology
IDCS is an extremely rare disease and skin involvement has rarely been reported. In a large pooled analysis of a total of 462 cases of dendritic cell sarcomas, there were 100 cases of IDCS with seven having skin findings (Saygin et al. 2013). Median age at diagnosis in this pooled analysis was 56.5 years (range 21 months to 88 years) with an M/F ratio of 1.38:1 (Saygin et al. 2013). A clonal relationship between IDCS and low-grade B-cell lymphomas has been reported in patients with both diseases (Feldman et al. 2008; Fraser et al. 2009; Shao et al. 2011). IDCS has been reported following the use of calcineurin inhibitors, and this may be due to their effect by dampening the responses of T cells to which IDCs present antigens (Gordon et al. 2007; Wu et al. 2010; Saygin et al. 2013).
Clinical Appearance of Cutaneous Lesions
Most lesions are asymptomatic and are nodular in nature. Nodules can be erythematous or brownish but not ulcerative. These lesions can occur anywhere and can appear in crops (Hui et al. 1987; Lee et al. 2009).
Pattern of Infiltration
IDCS usually is found throughout the dermis but spares the epidermis. The tumor can invade the subcutaneous tissue and can be seen in a fascicular pattern forming intertwining bundles (Hui et al. 1987; Lee et al. 2009).
Cytomorphology
Large spindle to ovoid cells are seen forming whorls. Cells have coarse nuclear chromatin with moderate to abundant cytoplasm resembling histiocytes albeit with indistinct borders (Ylagan et al. 2003). Small lymphocytes intermingling with the large histiocytic cell population is a key diagnostic feature that is less typical of carcinomas and sarcomas (Ylagan et al. 2003). In one series lymphoplasmacytic infiltration was seen in 63 % of tumors and rarely epithelioid cells were seen (7 %) (Saygin et al. 2013).
Immunophenotype
Cells are S100 positive and CD45 positive and have variable CD68 positivity (Gaertner et al. 2001; Pileri et al. 2002). Some IDCS are vimentin, HLA-DR, and fascin positive (Maeda et al. 2005). Lysozyme can also be positive (Gaertner et al. 2001). CD21 and CD35 will be negative (Ylagan et al. 2003). B-cell markers such as CD20 and T-cell markers such as CD3 and CD5 are usually negative. Cytokeratin, myeloperoxidase, CD1a, CD21, CD23, CD30, CD35, CD21, CD34, CD79a, BCL-2, and BCL-6 should all be negative (Gaertner et al. 2001; Pileri et al. 2002, 2007; Jiang et al. 2013). ATPase can be strongly positive in some cases (Turner et al. 1984; Fonseca et al. 1998). Birbeck granules are not seen on ultrastructure examination (Gaertner et al. 2001; Pileri et al. 2002).
Cytogenetic/Molecular Findings
Immunoglobulin and T-cell receptor genes are in a germ line configuration (Weiss et al. 1990).
Clinical Behavior
Prognosis is poor in cases of disseminated disease, and about half the patients will die of their disease. In the pooled analysis of 100 cases of IDCS, the median survival for patients with metastatic disease was 9 months, but cases with local disease did not reach median and 2-year survival rates (Saygin et al. 2013). In patients with localized disease, there was no difference in the overall survival between surgery and nonsurgical modalities such as radiation therapy (Saygin et al. 2013). In the metastatic setting, combined chemotherapy such as CHOP, ICE, and ABVD was most commonly used in patients with IDCS (Saygin et al. 2013). In metastatic IDCS, there was a statistical trend (P = 0.1) toward improved overall survival in those patients who received surgery, and these authors recommended surgery with adjuvant chemotherapy (Saygin et al. 2013).
Differential Diagnosis
Inflammatory pseudotumors typically show no histological atypia and are seen in patients with fever and other constitutional symptoms. Hodgkin lymphoma, which is remarkably rare in skin, and non-Hodgkin lymphoma may be considered if fibrosis is present inducing a pseudo-spindle morphology (Jayaram and Abdul Rahman 1997; Fonseca et al. 1998; Mohanty et al. 2003; Pillay et al. 2004). Langerhans cell sarcomas and other sarcomas such as peripheral nerve sheath tumors should be ruled out (Ylagan et al. 2003). Intranodal myofibroblastoma, true histiocytic lymphomas, melanomas, and anaplastic large-cell lymphomas are also considerations if spindle and anaplastic pattern is prominent (Fonseca et al. 1998).
Follicular Dendritic Cell Sarcoma (FDCS)
Definition
Follicular dendritic cells (FDC) present and retain antigens for B cells and stimulate B-cell proliferation and differentiation while having complex interactions with T cells (Tew et al. 1990; Wu et al. 1996; Fonseca et al. 1998). They are of mesenchymal origin. FDCS is a malignant expansion of FDC. FDCS usually presents as lymphadenopathy in the majority of cases but can present in a wide variety of extra nodal sites including the skin. In a large pooled analysis including 462 cases, 343 had FDCS and two of these had skin findings (Saygin et al. 2013).
Epidemiology
There is a wide age range with an adult predominance and a mean age of 44 years (Pileri et al. 2002; Nguyen et al. 2005). There is a female predominance for the inflammatory pseudotumor variant (Cheuk et al. 2001; Pileri et al. 2002; Vargas et al. 2002). FDCS can occur in association with Castleman disease usually in the hyaline vascular type (Chan et al. 1994). The inflammatory pseudotumor-like variant is associated with Epstein-Barr virus (EBV) (Arber et al. 1998). There may be an association between FDCS and autoimmunity with paraneoplastic pemphigus and myasthenia gravis seen in cases of FDCS (Lee et al. 1999; Wang et al. 2005; Meijs et al. 2008; Saygin et al. 2013).
Clinical Appearance of Cutaneous Lesions
Lesions can appear as subcutaneous nodules (Kazakov et al. 2005). In patients with FDCS, a paraneoplastic pemphigus can also occur and resembles ulcerations on the skin or mucosal surfaces, erythematous patches, or lichen planus.
Pattern of Infiltration
FDCS invading the tissue presents as spindle-shaped infiltrates in the dermis that may extend into the subcutaneous or even muscle but spares the epidermis (Kazakov et al. 2005).
Cytomorphology
Spindled to ovoid cells forming fascicles, whorls, diffuse sheets, or nodules are characteristic. Individual cells generally show indistinct cell borders and a moderate amount of eosinophilic cytoplasm. Nuclei are oval or elongated and finely dispersed chromatin. Nuclear pseudo-inclusions are common and binucleated and multinucleated tumor cells are seen (2008). On electron microscopy, the long cytoplasmic projections and desmosomal junctions are seen, while Birbeck granules and numerous lysosomes are not seen (Fonseca et al. 1998). Lymphoplasmacytic infiltration is frequently present in greater than 90 % of cases (Saygin et al. 2013). Rarely, Reed-Sternberg-like cells can lead to a mistaken diagnosis of Hodgkin disease (Mohanty et al. 2003) (see Fig. 16.5).
Follicular dendritic cell sarcoma (FDCS) with CD21 + CD35+ (inset) histiocytes
Immunophenotype
CD21, CD35, R4/23, Ki-FDC1p, and KiM4 are positive in FDCS (Chan et al. 1997; Fonseca et al. 1998; Ylagan et al. 2003). There is variable expression of CD68. Clusterin is strongly positive but is negative or weakly positive in other dendritic cell tumors (Grogg et al. 2004, 2005). Desmoplakin, vimentin, fascin, epidermal growth factor receptor (EGFR), CD45, and HLA-DR can be variable (Chan and Chan 1997; Fonseca et al. 1998; Sun et al. 2003; Ylagan et al. 2003).
Cytogenetic/Molecular Findings
Immunoglobulin and T-cell receptor genes are germ line configuration (Weiss et al. 1990). There is very limited data on genetic changes seen in patients with FDCS (Sander et al. 2007).
Clinical Behavior
Not much is known about skin-specific findings or clinical behavior because of the rarity of this disease in the skin. The most frequent location of lymphadenopathy is cervical and intra-abdominal and about half of patients will present with a local mass (Saygin et al. 2013). FDCS has a fairly benign course with median survival for local disease was 168 months (range 2–360 months). Risk of local recurrence and distant metastasis is around 27–28 % (Saygin et al. 2013). Larger tumor size (≥6 cm), presence of coagulative necrosis, high mitotic count (≥5 per 10 high-power fields), and cytological atypia are associated with poor prognosis (Chan et al. 1997; Shia et al. 2006; Saygin et al. 2013). Surgery is the mainstay of treatment for FDCS. Adjuvant therapy for fully resected patients is unclear. A pooled analysis showed no benefit of adjuvant radiation therapy (Saygin et al. 2013). This analysis did show that in the metastatic setting, treatment with combined adjuvant chemotherapy and radiotherapy (n = 23) only resulted in two deaths due to disease showing the importance of adjuvant treatment in advanced FDCS. Regimens designed for the management of aggressive lymphomas such as CHOP (cyclophosphamide, vincristine, doxorubicin, prednisone), ICE (ifosfamide, carboplatin, etoposide), and ABVD (adriamycin, bleomycin, vincristine, dacarbazine) have been tried with variable success (Saygin et al. 2013).
Differential Diagnosis
FDCS has the same differential diagnosis as IDCS. This includes ruling out inflammatory pseudotumors, histiocytic lymphomas, melanomas, Langerhans cell sarcomas, other sarcomas such as peripheral nerve sheath tumors (Ylagan et al. 2003), ALCL, IDCS, Hodgkin disease, intranodal myofibroblastoma, and NHL (Jayaram and Abdul Rahman 1997; Fonseca et al. 1998; Mohanty et al. 2003; Pillay et al. 2004).
Cutaneous Langerhans Cell Histiocytosis
Definition
Langerhans cell histiocytosis (LCH) represents a clonal accumulation of Langerhans cells that are a cutaneous antigen presenting cells (Newman et al. 2007). After being triggered by a new antigen, the LC migrates to the regional lymph nodes and activates antigen-specific T cells that return to the skin (Romani et al. 2003). Cutaneous lesions are present in one third of patients. In the Hashimoto-Pritzker disease, also known as congenital, self-healing reticulohistiocytosis, disease is limited to the skin and resolves rapidly over a period of weeks (Divaris et al. 1991). This is a rare disease and is more commonly seen in children than adults.
Epidemiology
Incidence is 5 per million populations per year with most cases occurring in childhood. There is a predilection for males (Pileri et al. 2002; Salotti et al. 2009). The WHO states that the disease is more common in northern European descent patients and rare in blacks (2008). LCH usually presents with either unifocal or multifocal bone disease or as a multisystem disease. LCH has been associated with Epstein-Barr virus, malaria, and leukemias (Newman et al. 2007). In a large series of 314 patients diagnosed between 1946 and 1996, the median age at diagnosis was 24.5 years (Howarth et al. 1999). Isolated skin findings were seen in 14 patients of this series. There are disease processes that include LCH. Letterer-Siwe disease usually presents in the first 2 years of life and is the acute disseminated form of LCH (Newman et al. 2007). Hand-Schuller-Christian disease is a chronic multisystem disease seen in older children and consists of the classic triad of bone disease, diabetes insipidus, and exophthalmos (Gianotti and Caputo 1985). Eosinophilic granuloma of bone is a common manifestation of LCH in adults. The most frequent anatomical sites of LCH in adults were the lung (62 %), bone (50 %), and skin (15 %). One-third of patients developed multiple organ involvement (Gotz and Fichter 2004).
In contrast to acute illness observed in children, LCH in adults has usually more chronic course.
Clinical Appearance of Cutaneous Lesions
Patients with Letterer-Siwe disease have extensive cutaneous lesions and classically resemble seborrheic dermatitis with involvement of the scalp, face, trunk, and perineum (Zachary and MacDonald 1983). Hand-Schuller-Christian disease has papulonodular, granulomatous, or seborrheic dermatitis-like lesions (Zachary and MacDonald 1983). In Hashimoto-Pritzker disease, lesions are seen at birth and are widespread reddish-brown nodules that regress (Divaris et al. 1991). LCH can also present with papules, pustules, vesicles, petechiae, or purpura (Zachary and MacDonald 1983; Stein et al. 2001; Park et al. 2012).
Pattern of Infiltration
Dermal infiltrate of large epithelioid cells with abundant eosinophilic cytoplasm and indented or reniform nuclei (Hashimoto and Pritzker 1973).
Cytomorphology
Oval cells about 10–15 μm in size with grooved, folded, or indented or lobulated nuclei with fine chromatin are seen (2008) (WHO) (see Fig. 16.6). Placental alkaline phosphatase can be used in archival material to evaluate for LCH (Newman et al. 2007). Eosinophils are scattered throughout the infiltrate and the epidermis is free of infiltrating cells (Hashimoto and Pritzker 1973). Letterer-Siwe disease has infiltrates that are composed largely of LCs with scattered lymphocytes, eosinophils, and occasional neutrophils (Wells 1979). In Hand-Schuller-Christian disease, there is a prominent granulomatous reaction made of aggregates of histiocytes and rarely cells with xanthomatous changes (Altman and Winkelmann 1963). In Hand-Schuller-Christian disease, clusters of eosinophils are prominent and there are occasional multinucleated giant cells (Risdall et al. 1983). Birbeck granules which have a tennis racquet shape and zipper-like appearance are present in 0–40 % of cells by electron microscopy (Zunino-Goutorbe et al. 2008). An ultrastructural finding that has been proposed to be specific for congenital self-healing reticulohistiocytosis (CSHR) is the presence of concentrically laminated dense-core bodies in the same cells that contain Birbeck granules (Hashimoto et al. 1984).
Langerhans cell histiocytosis with eosinophilic neoplastic cells, some with grooved nuclei positive for CD1a and S100
Immunophenotype
LCH stain positive for S-100 protein, CD1a, CD45, and CD101. CD1a staining is specific for LCH (Newman et al. 2007). CD68 staining can be positive (Wheller et al. 2013). Langerin (CD207) is also specific for LCH (Chikwava and Jaffe 2004; Lau et al. 2008). Placental alkaline phosphatase can be used in archival material to evaluate for LCH (Newman et al. 2007). LCH do not express CD34 or MS-1 (a marker for dendritic perivascular macrophages that are found in non-LCD histiocytosis) (Goerdt et al. 1993).
Cytogenetics/Molecular Findings
LCH has been shown to be clonal by X-linked androgen receptor gene assay (HUMARA) (Willman et al. 1994; Yu et al. 1994; Yousem et al. 2001). No consistent molecular genetic defect has been identified (Murakami et al. 2002). Recently, recurrent BRAF V600E somatic mutation was identified in 35 of 61 patients (57 %) with LCH (Badalian-Very et al. 2010).
Clinical Behavior
Self-limited LCH should be distinguished from other forms of LCH because disseminated disease has a worse prognosis and requires an aggressive therapy such as chemotherapy. Thorough investigation and follow-up of patients with LCH should be performed because clinically, histopathologically, and immunohistochemically, one cannot determine those individuals with more aggressive disease (Kapur et al. 2007; Wheller et al. 2013). In self-limited disease, one group suggests a follow-up period of 2 years including laboratory tests and radiographs (abdominal ultrasound and chest x-ray (Zunino-Goutorbe et al. 2008). LCH can lead to diabetes insipidus due to infiltration and scarring in the hypothalamic pituitary area or due to an autoimmune process with antibodies to vasopressin (Dunger et al. 1989; Grois et al. 1995, 2006). The most important risk factor for developing DI in patients with LCH was multisystem disease (Grois et al. 2006). Self-limited disease of the skin can be treated with topical nitrogen mustard (Wong et al. 1986; Munn and Chu 1998; Stein et al. 2001), psoralen plus ultraviolet A (PUVA) phototherapy (Munn and Chu 1998; Stein et al. 2001), imiquimod (Taverna et al. 2006), excimer laser (Vogel et al. 2008), and radiation therapy (Lichtenwald et al. 1991). Though most patients are initially treated with corticosteroids, thalidomide (Imanaka et al. 2004; Park et al. 2012), and etoposide have the best results for patients with widespread cutaneous disease (Munn and Chu 1998; McClain 2005; McClain and Kozinetz 2007; Gadner et al. 2008; Park et al. 2012). Agents such as methotrexate, cyclophosphamide, cyclosporine, 6-mercaptopurine, and vinblastine have also been reported to work (McLelland et al. 1990; Munn and Chu 1998; Stockschlaeder and Sucker 2006; Park et al. 2012). Current treatment should be based on the Histiocyte Society evaluation and treatment guidelines with current recommendations for treatment of all categories, excluding single-system disease to be systemic therapy (Minkov et al. 2009; French Histiocytosis Society 1996). Currently, for systemic involvement, prednisone and vinblastine for 12 months are the recommended treatment (Gadner et al. 2008; Minkov et al. 2009; Gadner et al. 2013). One year of therapy was proven to decrease recurrence when compared to six cycles (Gadner et al. 2013). Progressive disease or recurrence should be treated with 2-chlorodeoxyadenosine and cytarabine (Bernard et al. 2005). Stem cell transplantation should be considered in these patients (Steiner et al. 2005). This disease can affect the skin or other organs. Recent case series has suggested that an inhibitor of mutated BRAF (vemurafenib) could be a novel promising targeted therapy for patients with LCH carrying V600E mutation (Haroche et al. 2013).
Differential Diagnosis
LCH can be mistaken for disorders that cause Langerhans cell hyperplasia such as scabies, contact dermatitis, indeterminate dendritic cell infiltrates, pityriasis lichenoides et varioliformis acuta, and different T-cell lymphoproliferative disorders such as lymphomatoid papulosis, mycosis fungoides, parapsoriasis, or cutaneous T-cell hyperplasia (Christie et al. 2006; Pigozzi et al. 2006; Bhattacharjee and Glusac 2007; Drut et al. 2010). Since it can involve the skeleton in adults, it can be confused for multiple myeloma (Malpas 1998).
Dermal Dendrocytic Infiltrates
Definition
Dermal dendrocytes encompass a double population of dermal-resident cells that include CD34+ cells and factor XIIIa-positive cells. These two cell types have different resident sites and function (Sontheimer et al. 1989; Hoyo et al. 1993; Narvaez et al. 1996; Drut 2007). CD34 also labels dermal dendrocytes, with an overlapping immunoprofile with CD34 expression seen in cellular dermatofibroma. Lesions may harbor some cells expressing the alternative antigen though the majority do not (Goldblum and Tuthill 1997).
Epidemiology
Rare cases often mistaken for neurofibromas. Can present in infant and early childhood as hamartomas.
Clinical Appearance of Cutaneous Lesions
Well-circumscribed atrophic and wrinkled patch on the skin. These can look similar to a congenital melanocytic nevus or skin-colored papules (Cerio et al. 1989; Ohata and Kawahara 2002; Drut 2007).
Pattern of Infiltration
Dermal proliferation of fusiform cells. Epidermal atrophy can be seen.
Cytomorphology
Fusiform or spindle-shaped cells that are seen in the dermis. These can be arranged in several layers and around small vessels (Drut 2007).
Immunophenotype
The tumor cells are positive for CD34+ and factor XIIIa and are usually negative for S100 (Cerio et al. 1989; Hoyo et al. 1993; Narvaez et al. 1996; Goldblum and Tuthill 1997).
Clinical Behavior
These lesions are usually benign and do not require intensive treatment (see Fig. 16.7).
Factor XIIIa positive dendrocytes
Differential Diagnosis
Neurofibroma, dermatofibrosarcoma protuberans, and giant-cell fibroblastoma should all be considered in the differential. Xanthomas and even indeterminate dendritic neoplasm can stain with Factox XIII and figures in the differential of immunstain results. Staining for factor XIIIa is the most sensitive test for dermal dendrocytic infiltrates (Cerio et al. 1989; Sontheimer et al. 1989; Gray et al. 1990; Hoyo et al. 1993; Narvaez et al. 1996; Goldblum and Tuthill 1997; Ohata and Kawahara 2002; Drut 2007).
Indeterminate Dendritic Cell Infiltrates
Definition
Indeterminate dendritic cell tumor, also known as indeterminate cell histiocytosis (ICH), is a neoplastic proliferation of normal dendritic accessory cells, usually found in the dermis. These cells should lack intracytoplasmic Birbeck granules but share morphologic and immunophenotypical features with Langerhans cells (Ferran et al. 2007). Since Langerhans cells lose their Birbeck granules when cultured and since some indeterminate cells migrate to the epidermis and may become Langerhans cells, some authors speculate that indeterminate cells may represent a mature form of Langerhans cells (Chu et al. 1982; Romani et al. 1989; Teunissen et al. 1990; Weiss et al. 2005).
Epidemiology
Indeterminate dendritic cell tumor is a very rare disorder and may be associated with low-grade B-cell lymphoma (Vasef et al. 1995).
Clinical Appearance of Cutaneous Lesions
Solitary or multiple asymptomatic maculopapular or papulo-nodular lesions (Rosenberg and Morgan 2001; Ferran et al. 2007). Most lesions are located on the trunk, face, neck, or extremities. Rarely, generalized distribution has been reported (Sidoroff et al. 1996).
Pattern of Infiltration
A diffuse infiltrate comprising of cells with irregular nuclear grooves and clefts that resemble Langerhans cells. Infiltration is seen in the dermis but may extend into the subcutaneous fat. The epidermis is sparred (Rosenberg and Morgan 2001).
Cytomorphology
Cells resemble Langerhans cells with irregular nuclear grooves and clefts. Cytoplasm is abundant and eosinophilic. Multinucleated giant cells may be seen and there may be spindling of some cells. Cytoplasm is abundant and is eosinophilic. These cells lack Birbeck granules. Desmosomes are lacking but the cells can have interdigitating cell processes (2008).
Immunophenotype
Indeterminate cells usually express S-100 and CD1a antigens but always lack Birbeck granules on ultrastructural exam (Ferran et al. 2007). Desmosomes are lacking but there can be complex interdigitating cell processes. These cells are negative for specific B- and T-cell markers, CD30, CD163, CD21, CD23, and CD35. There is variable positivity for CD45, CD68, lysozyme, and CD4 (Vener et al. 2007) (see Fig. 16.8).
(a) Indeterminate dendritic cell sarcoma. (b) CD68 stain. (c) S100 stain
Cytogenetic/Molecular Findings
One case was shown to be clonal by human androgen receptor gene assay (Vener et al. 2007).
Clinical Behavior
Disease is usually limited to the skin and extra cutaneous lesions and systemic symptoms are rare (Ferran et al. 2007). Etiology of this disorder remains unknown, but it has been postulated that it can represent a reactive disorder secondary to antigenic exposure (Ratzinger et al. 2005). Proliferations of indeterminate cells have been seen in nodular scabies (Hashimoto et al. 2000) and in healed lesions of pityriasis rosea (Wollenberg et al. 2002).
Differential Diagnosis
The differential diagnosis is similar to that for LCH and includes LCH, scabies, pityriasis rosea, and T-cell lymphomas.
Conclusions
The different myelomonocytic infiltrates can be associated with underlying systemic disorders such as EMH in patients with primary myelofibrosis or infiltrates related to MDS or AML or can be a primary disorder on their own. The broad differential diagnosis includes being able to differentiate myelomonocytic infiltrates into a specific subtype and also to exclude other similar causes such as precursor lymphoblastic leukemia (see Fig. 16.9) which may present with papulo-nodular tumors as with other myelomonocytic infiltrates but will have a different cytomorphology and immunophenotypical profile (CD10, Pax5, CD22 positive). Table 16.2 summarizes the different immunophenotypical markers that can be used to help differentiate between the different myelomonocytic infiltrates discussed above.
(a) Lymphoblastic lymphoma in skin. (b) Lymphoblasts with abnormal mitosis, finely dispersed chromatin. (c) TdT nuclear-positive lymphoblasts
Differentiation of each disease entity relies on the use of clinical findings and careful evaluation of the cytomorphology and immunophenotypical profile including evaluation of atypical cells circulating in the peripheral blood (see Fig. 16.10).
(a) Circulating cerebriform lymphocytes and (b) circulating blast, in oil magnification, to contrast the nuclear chromatin pattern and contours
Consensus on the treatment of these disorders continues to be difficult due to the rare nature of many of these diseases. Consortium group recommendations and when possible, clinical trials should be the mainstay of treatment decisions. Prognosis can be variable and further research is needed to use targeted therapy in these rare tumor subtypes.
References
A multicentre retrospective survey of Langerhans’ cell histiocytosis: 348 cases observed between 1983 and 1993. The French Langerhans’ Cell Histiocytosis Study Group. Arch Dis Child. 1996;75(1): 17–24.
Swerdlow et al. (eds). WHO classification of tumours of haematopoietic and lymphoid tissues. Lyon: International Agency for Research on Cancer; 2008.
Agis H, Weltermann A, et al. A comparative study on demographic, hematological, and cytogenetic findings and prognosis in acute myeloid leukemia with and without leukemia cutis. Ann Hematol. 2002;81(2):90–5.
Altman J, Winkelmann RK. Xanthomatous cutaneous lesions of histiocytosis X. Arch Dermatol. 1963;87:164–70.
Arber DA, Weiss LM, et al. Detection of Epstein-Barr virus in inflammatory pseudotumor. Semin Diagn Pathol. 1998;15(2):155–60.
Ascani S, Massone C, et al. CD4-negative variant of CD4+/CD56+ hematodermic neoplasm: description of three cases. J Cutan Pathol. 2008;35(10):911–5.
Assaf C, Gellrich S, et al. CD56-positive haematological neoplasms of the skin: a multicentre study of the Cutaneous Lymphoma Project Group of the European Organisation for Research and Treatment of Cancer. J Clin Pathol. 2007;60(9):981–9.
Badalian-Very G, Vergilio JA, et al. Recurrent BRAF mutations in Langerhans cell histiocytosis. Blood. 2010;116(11):1919–23.
Bakst R, Wolden S, et al. Radiation therapy for chloroma (granulocytic sarcoma). Int J Radiat Oncol Biol Phys. 2012;82(5):1816–22.
Bekassy AN, Hermans J, et al. Granulocytic sarcoma after allogeneic bone marrow transplantation: a retrospective European multicenter survey. Acute and Chronic Leukemia Working Parties of the European Group for Blood and Marrow Transplantation. Bone Marrow Transplant. 1996;17(5):801–8.
Bernard F, Thomas C, et al. Multi-centre pilot study of 2-chlorodeoxyadenosine and cytosine arabinoside combined chemotherapy in refractory Langerhans cell histiocytosis with haematological dysfunction. Eur J Cancer. 2005;41(17):2682–9.
Bhattacharjee P, Glusac EJ. Langerhans cell hyperplasia in scabies: a mimic of Langerhans cell histiocytosis. J Cutan Pathol. 2007;34(9):716–20.
Bluefarb SM, Webster JR. Leukemia cutis simulating venereal disease. Q Bull Northwest Univ Med Sch. 1953;27(1):18–20.
Bouroncle BA, Doan CA. Myelofibrosis. Clinical, hematologic and pathologic study of 110 patients. Am J Med Sci. 1962;243:697–715.
Breccia M, Mandelli F, et al. Clinico-pathological characteristics of myeloid sarcoma at diagnosis and during follow-up: report of 12 cases from a single institution. Leuk Res. 2004;28(11):1165–9.
Burns A. Observations of surgical anatomy, head and neck. Edinburgh: Thomas Royace and Company; 1811. p. 364–6.
Burns CA, Scott GA, et al. Leukemia cutis at the site of trauma in a patient with Burkitt leukemia. Cutis. 2005;75(1):54–6.
Burton JL. Sweet’s syndrome, pyoderma gangrenosum and acute leukaemia. Br J Dermatol. 1980;102(2):239.
Byrd JC, Edenfield WJ, et al. Extramedullary myeloid cell tumors in acute nonlymphocytic leukemia: a clinical review. J Clin Oncol. 1995;13(7):1800–16.
Cerio R, Spaull J, et al. Histiocytoma cutis: a tumour of dermal dendrocytes (dermal dendrocytoma). Br J Dermatol. 1989;120(2):197–206.
Chan J, Chan J. PRoliferative lesions of follicular dendritic cells: an overview, including a detailed account of follicular dendritic cell sarcoma, a neoplasm with many faces and uncommon etiologic associations. Adv Anat Pathol. 1997;4:387–411.
Chan JK, Fletcher CD, et al. Follicular dendritic cell sarcoma. Clinicopathologic analysis of 17 cases suggesting a malignant potential higher than currently recognized. Cancer. 1997;79(2):294–313.
Chan JK, Tsang WY, et al. Follicular dendritic cell tumor and vascular neoplasm complicating hyaline-vascular Castleman’s disease. Am J Surg Pathol. 1994;18(5):517–25.
Cheuk W, Chan JK, et al. Inflammatory pseudotumor-like follicular dendritic cell tumor: a distinctive low-grade malignant intra-abdominal neoplasm with consistent Epstein-Barr virus association. Am J Surg Pathol. 2001;25(6):721–31.
Chikwava K, Jaffe R. Langerin (CD207) staining in normal pediatric tissues, reactive lymph nodes, and childhood histiocytic disorders. Pediatr Dev Pathol. 2004;7(6):607–14.
Cho-Vega JH, Medeiros LJ, et al. Leukemia cutis. Am J Clin Pathol. 2008;129(1):130–42.
Christie LJ, Evans AT, et al. Lesions resembling Langerhans cell histiocytosis in association with other lymphoproliferative disorders: a reactive or neoplastic phenomenon? Hum Pathol. 2006;37(1):32–9.
Chu A, Eisinger M, et al. Immunoelectron microscopic identification of Langerhans cells using a new antigenic marker. J Invest Dermatol. 1982;78(2):177–80.
Chung NP, Chen Y, et al. Dendritic cells: sentinels against pathogens. Histol Histopathol. 2004;19(1):317–24.
Collie AM, Uchin JM, et al. Cutaneous intravascular extramedullary hematopoiesis in a patient with post-polycythemia vera myelofibrosis. J Cutan Pathol 2013;40(7):616–20.
Corella F, Barnadas MA, et al. A case of cutaneous extramedullary hematopoiesis associated with idiopathic myelofibrosis. Actas Dermosifiliogr 2008;99(4):297–300.
Cota C, Vale E, et al. Cutaneous manifestations of blastic plasmacytoid dendritic cell neoplasm-morphologic and phenotypic variability in a series of 33 patients. Am J Surg Pathol. 2010;34(1):75–87.
Cronin DM, George TI, et al. An updated approach to the diagnosis of myeloid leukemia cutis. Am J Clin Pathol. 2009;132(1):101–10.
Dachary D, Bernard P, et al. Acute myeloid leukemia with marrow hypereosinophilia and chromosome 16 abnormality. Cancer Genet Cytogenet. 1986;20(3–4):241–6.
Dalle S, Beylot-Barry M, et al. Blastic plasmacytoid dendritic cell neoplasm: is transplantation the treatment of choice? Br J Dermatol. 2010;162(1):74–9.
de Morais JC, Spector N, et al. Spinal cord compression due to extramedullary hematopoiesis in the proliferative phase of polycythemia vera. Acta Haematol. 1996;96(4):242–4.
Dibbern Jr DA, Loevner LA, et al. MR of thoracic cord compression caused by epidural extramedullary hematopoiesis in myelodysplastic syndrome. AJNR Am J Neuroradiol. 1997;18(2):363–6.
Divaris DX, Ling FC, et al. Congenital self-healing histiocytosis. Report of two cases with histochemical and ultrastructural studies. Am J Dermatopathol. 1991;13(5):481–7.
Drut R. Polypoid dermal dendrocytic hamartoma in a giant congenital melanocytic nevus. Int J Surg Pathol. 2007;15(1):73–6.
Drut R, Peral CG, et al. Langerhans cell hyperplasia of the skin mimicking Langerhans cell histiocytosis: a report of two cases in children not associated with scabies. Fetal Pediatr Pathol. 2010;29(4):231–8.
Dunger DB, Broadbent V, et al. The frequency and natural history of diabetes insipidus in children with Langerhans-cell histiocytosis. N Engl J Med. 1989;321(17):1157–62.
Eshghabadi M, Shojania AM, et al. Isolated granulocytic sarcoma: report of a case and review of the literature. J Clin Oncol. 1986;4(6):912–7.
Falini B, Lenze D, et al. Cytoplasmic mutated nucleophosmin (NPM) defines the molecular status of a significant fraction of myeloid sarcomas. Leukemia. 2007;21(7):1566–70.
Falini B, Mecucci C, et al. Cytoplasmic nucleophosmin in acute myelogenous leukemia with a normal karyotype. N Engl J Med. 2005;352(3):254–66.
Feldman AL, Arber DA, et al. Clonally related follicular lymphomas and histiocytic/dendritic cell sarcomas: evidence for transdifferentiation of the follicular lymphoma clone. Blood. 2008;111(12):5433–9.
Fernandez Acenero MJ, Borbujo J, et al. Extramedullary hematopoiesis in an adult. J Am Acad Dermatol. 2003;48(5 Suppl):S62–3.
Ferran M, Toll A, et al. Acquired mucosal indeterminate cell histiocytoma. Pediatr Dermatol. 2007;24(3):253–6.
Ferrara F, Cancemi D, et al. Tetrasomy 8 and t(1;11)(p32;q24) in acute myelo-monocytic leukemia with extensive leukemic cutaneous involvement. Leuk Lymphoma. 1996;20(5–6):513–5.
Feuillard J, Jacob MC, et al. Clinical and biologic features of CD4(+)CD56(+) malignancies. Blood. 2002;99(5):1556–63.
Fonseca R, Yamakawa M, et al. Follicular dendritic cell sarcoma and interdigitating reticulum cell sarcoma: a review. Am J Hematol. 1998;59(2):161–7.
Fraser CR, Wang W, et al. Transformation of chronic lymphocytic leukemia/small lymphocytic lymphoma to interdigitating dendritic cell sarcoma: evidence for transdifferentiation of the lymphoma clone. Am J Clin Pathol. 2009;132(6):928–39.
Gadner H, Grois N, et al. Improved outcome in multisystem Langerhans cell histiocytosis is associated with therapy intensification. Blood. 2008;111(5):2556–62.
Gadner H, Minkov M, et al. Therapy prolongation improves outcome in multisystem Langerhans cell histiocytosis. Blood. 2013;121(25):5006–14.
Gaertner EM, Tsokos M, et al. Interdigitating dendritic cell sarcoma. A report of four cases and review of the literature. Am J Clin Pathol. 2001;115(4):589–97.
Garnache-Ottou F, Feuillard J, et al. Extended diagnostic criteria for plasmacytoid dendritic cell leukaemia. Br J Haematol. 2009;145(5):624–36.
Gianotti F, Caputo R. Histiocytic syndromes: a review. J Am Acad Dermatol. 1985;13(3):383–404.
Glew RH, Haese WH, et al. Myeloid metaplasia with myelofibrosis. The clinical spectrum of extramedullary hematopoiesis and tumor formation. Johns Hopkins Med J. 1973;132(5):253–70.
Goerdt S, Kolde G, et al. Immunohistochemical comparison of cutaneous histiocytoses and related skin disorders: diagnostic and histogenetic relevance of MS-1 high molecular weight protein expression. J Pathol. 1993;170(4):421–7.
Goldblum JR, Tuthill RJ. CD34 and factor-XIIIa immunoreactivity in dermatofibrosarcoma protuberans and dermatofibroma. Am J Dermatopathol. 1997;19(2):147–53.
Gordon MK, Kraus M, et al. Interdigitating dendritic cell tumors in two patients exposed to topical calcineurin inhibitors. Leuk Lymphoma. 2007;48(4):816–8.
Gotz G, Fichter J. Langerhans’-cell histiocytosis in 58 adults. Eur J Med Res. 2004;9(11):510–4.
Gould J, Iqbal A, et al. Pentasomy 8 in acute monoblastic leukemia. Cancer Genet Cytogenet. 2000;117(2):146–8.
Gowitt GT, Zaatari GS. Bronchial extramedullary hematopoiesis preceding chronic myelogenous leukemia. Hum Pathol. 1985;16(10):1069–71.
Gray MH, Smoller BR, et al. Giant dermal dendrocytoma of the face: a distinct clinicopathologic entity. Arch Dermatol. 1990;126(5):689–90.
Grogg KL, Lae ME, et al. Clusterin expression distinguishes follicular dendritic cell tumors from other dendritic cell neoplasms: report of a novel follicular dendritic cell marker and clinicopathologic data on 12 additional follicular dendritic cell tumors and 6 additional interdigitating dendritic cell tumors. Am J Surg Pathol. 2004;28(8):988–98.
Grogg KL, Macon WR, et al. A survey of clusterin and fascin expression in sarcomas and spindle cell neoplasms: strong clusterin immunostaining is highly specific for follicular dendritic cell tumor. Mod Pathol. 2005;18(2):260–6.
Grois N, Flucher-Wolfram B, et al. Diabetes insipidus in Langerhans cell histiocytosis: results from the DAL-HX 83 study. Med Pediatr Oncol. 1995;24(4):248–56.
Grois N, Potschger U, et al. Risk factors for diabetes insipidus in Langerhans cell histiocytosis. Pediatr Blood Cancer. 2006;46(2):228–33.
Gruson B, Vaida I, et al. L-asparaginase with methotrexate and dexamethasone is an effective treatment combination in blastic plasmacytoid dendritic cell neoplasm. Br J Haematol. 2013;163:543–5.
Gumbs RV, Higginbotham-Ford EA, et al. Thoracic extramedullary hematopoiesis in sickle-cell disease. AJR Am J Roentgenol. 1987;149(5):889–93.
Guo J, Si L, et al. Phase II, open-label, single-arm trial of imatinib mesylate in patients with metastatic melanoma harboring c-Kit mutation or amplification. J Clin Oncol. 2011;29(21):2904–9.
Haniffa MA, Wilkins BS, et al. Cutaneous extramedullary hemopoiesis in chronic myeloproliferative and myelodysplastic disorders. J Am Acad Dermatol. 2006;55(2 Suppl):S28–31.
Hanson CA, Abaza M, et al. Acute biphenotypic leukaemia: immunophenotypic and cytogenetic analysis. Br J Haematol. 1993;84(1):49–60.
Haroche J, Cohen-Aubart F, et al. Dramatic efficacy of vemurafenib in both multisystemic and refractory Erdheim-Chester disease and Langerhans cell histiocytosis harboring the BRAF V600E mutation. Blood. 2013;121(9):1495–500.
Hashimoto K, Fujiwara K, et al. Post-scabetic nodules: a lymphohistiocytic reaction rich in indeterminate cells. J Dermatol. 2000;27(3):181–94.
Hashimoto K, Pritzker MS. Electron microscopic study of reticulohistiocytoma. An unusual case of congenital, self-healing reticulohistiocytosis. Arch Dermatol. 1973;107(2):263–70.
Hashimoto K, Takahashi S, et al. Congenital self-healing reticulohistiocytosis. Report of the seventh case with histochemical and ultrastructural studies. J Am Acad Dermatol. 1984;11(3):447–54.
Herling M, Jones D. CD4+/CD56+ hematodermic tumor: the features of an evolving entity and its relationship to dendritic cells. Am J Clin Pathol. 2007;127(5):687–700.
Herling M, Teitell MA, et al. TCL1 expression in plasmacytoid dendritic cells (DC2s) and the related CD4+ CD56+ blastic tumors of skin. Blood. 2003;101(12):5007–9.
Howarth DM, Gilchrist GS, et al. Langerhans cell histiocytosis: diagnosis, natural history, management, and outcome. Cancer. 1999;85(10):2278–90.
Hoyo E, Kanitakis J, et al. The dermal dendrocyte. Pathol Biol (Paris). 1993;41(7):613–8.
Hui PK, Feller AC, et al. Skin tumor of T accessory cells (interdigitating reticulum cells) with high content of T lymphocytes. Am J Dermatopathol. 1987;9(2):129–37.
Hurley MY, Ghahramani GK, et al. Cutaneous myeloid sarcoma: natural history and biology of an uncommon manifestation of acute myeloid leukemia. Acta Derm Venereol. 2013;93(3):319–24.
Imai Y, Yamakawa M, et al. The lymphocyte-dendritic cell system. Histol Histopathol. 1998;13(2):469–510.
Imanaka A, Tarutani M, et al. Langerhans cell histiocytosis involving the skin of an elderly woman: a satisfactory remission with oral prednisolone alone. J Dermatol. 2004;31(12):1023–6.
Jacob MC, Chaperot L, et al. CD4+ CD56+ lineage negative malignancies: a new entity developed from malignant early plasmacytoid dendritic cells. Haematologica. 2003;88(8):941–55.
Jardin F, Callanan M, et al. Recurrent genomic aberrations combined with deletions of various tumour suppressor genes may deregulate the G1/S transition in CD4+CD56+ haematodermic neoplasms and contribute to the aggressiveness of the disease. Leukemia. 2009;23(4):698–707.
Jayaram G, Abdul Rahman N. Cytology of Ki-1-positive anaplastic large cell lymphoma. A report of two cases. Acta Cytol. 1997;41(4 Suppl):1253–60.
Jiang YZ, Dong NZ, et al. Interdigitating dendritic cell sarcoma presenting simultaneously with acute myelomonocytic leukemia: report of a rare case and literature review. Int J Hematol. 2013;97(5):657–66.
Julia F, Petrella T, et al. Blastic plasmacytoid dendritic cell neoplasm: clinical features in 90 patients. Br J Dermatol. 2013;169:579–86.
Kapur P, Erickson C, et al. Congenital self-healing reticulohistiocytosis (Hashimoto-Pritzker disease): ten-year experience at Dallas Children’s Medical Center. J Am Acad Dermatol. 2007;56(2):290–4.
Kaune KM, Baumgart M, et al. Solitary cutaneous nodule of blastic plasmacytoid dendritic cell neoplasm progressing to overt leukemia cutis after chemotherapy: immunohistology and FISH analysis confirmed the diagnosis. Am J Dermatopathol. 2009;31(7):695–701.
Kawakami T, Kimura S, et al. Transforming growth factor-beta overexpression in cutaneous extramedullary hematopoiesis of a patient with myelodysplastic syndrome associated with myelofibrosis. J Am Acad Dermatol 2008;58(4):703–6.
Kazakov DV, Morrisson C, et al. Sarcoma arising in hyaline-vascular castleman disease of skin and subcutis. Am J Dermatopathol. 2005;27(4):327–32.
King A. A case of chloroma. Mon J Med. 1853;17:97.
Koch CA, Li CY, et al. Nonhepatosplenic extramedullary hematopoiesis: associated diseases, pathology, clinical course, and treatment. Mayo Clin Proc. 2003;78(10):1223–33.
Korsten J, Grossman H, et al. Extramedullary hematopoiesis in patients with thalassemia anemia. Radiology. 1970;95(2):257–63.
Krause JR. Granulocytic sarcoma preceding acute leukemia: a report of six cases. Cancer. 1979;44(3):1017–21.
Kumar PV. Leukemia cutis. Fine needle aspiration findings. Acta Cytol. 1997;41(3):666–71.
Kwon KS, Lee JB, et al. A case of cutaneous extramedullary hematopoiesis in myelofibrosis with a preponderance of eosinophilic precursor cells. J Dermatol 1999;26(6):379–84.
Lane JE, Walker AN, et al. Cutaneous sclerosing extramedullary hematopoietic tumor in chronic myelogenous leukemia. J Cutan Pathol 2002;29(10):608–12.
Lau SK, Chu PG, et al. Immunohistochemical expression of Langerin in Langerhans cell histiocytosis and non-Langerhans cell histiocytic disorders. Am J Surg Pathol. 2008;32(4):615–9.
Lee IJ, Kim SC, et al. Paraneoplastic pemphigus associated with follicular dendritic cell sarcoma arising from Castleman’s tumor. J Am Acad Dermatol. 1999;40(2 Pt 2):294–7.
Lee JC, Christensen T, et al. Metastatic interdigitating dendritic cell sarcoma masquerading as a skin primary tumor: a case report and review of the literature. Am J Dermatopathol. 2009;31(1):88–93.
Lee E, Park HJ, et al. Leukemia cutis as early relapse of T-cell acute lymphoblastic leukemia. Int J Dermatol. 2010;49(3):335–7.
Leroux D, Mugneret F, et al. CD4(+), CD56(+) DC2 acute leukemia is characterized by recurrent clonal chromosomal changes affecting 6 major targets: a study of 21 cases by the Groupe Francais de Cytogenetique Hematologique. Blood. 2002;99(11):4154–9.
Lewkow LM, Shah I. Sickle cell anemia and epidural extramedullary hematopoiesis. Am J Med. 1984;76(4):748–51.
Lichtenwald DJ, Jakubovic HR, et al. Primary cutaneous Langerhans cell histiocytosis in an adult. Arch Dermatol. 1991;127(10):1545–8.
Lim D, Goodman H, et al. Blastic plasmacytoid dendritic cell neoplasm. Australas J Dermatol. 2013;54(2):e43–5.
Lin CK, Liang R, et al. Myelodysplastic syndrome presenting with generalized cutaneous granulocytic sarcomas. Acta Haematol. 1990;83(2):89–93.
List AF, Gonzalez-Osete G, et al. Granulocytic sarcoma in myelodysplastic syndromes: clinical marker of disease acceleration. Am J Med. 1991;90(2):274–6.
Liu PI, Ishimaru T, et al. Autopsy study of granulocytic sarcoma (chloroma) in patients with myelogenous leukemia, Hiroshima-Nagasaki 1949–1969. Cancer. 1973;31(4):948–55.
Liu K, Victora GD, et al. In vivo analysis of dendritic cell development and homeostasis. Science. 2009;324(5925):392–7.
Lucioni M, Novara F, et al. Twenty-one cases of blastic plasmacytoid dendritic cell neoplasm: focus on biallelic locus 9p21.3 deletion. Blood. 2011;118(17):4591–4.
Maeda K, Takahashi T, et al. Interdigitating cell sarcoma: a report of an autopsy case and literature review. J Clin Exp Hematopathol. 2005;45:37–44.
Malpas JS. Langerhans cell histiocytosis in adults. Hematol Oncol Clin N Am. 1998;12(2):259–68.
Marafioti T, Paterson JC, et al. Novel markers of normal and neoplastic human plasmacytoid dendritic cells. Blood. 2008;111(7):3778–92.
McClain KL. Drug therapy for the treatment of Langerhans cell histiocytosis. Expert Opin Pharmacother. 2005;6(14):2435–41.
McClain KL, Kozinetz CA. A phase II trial using thalidomide for Langerhans cell histiocytosis. Pediatr Blood Cancer. 2007;48(1):44–9.
McLelland J, Broadbent V, et al. Langerhans cell histiocytosis: the case for conservative treatment. Arch Dis Child. 1990;65(3):301–3.
Meijs M, Mekkes J, et al. Paraneoplastic pemphigus associated with follicular dendritic cell sarcoma without Castleman’s disease; treatment with rituximab. Int J Dermatol. 2008;47(6):632–4.
Meis JM, Butler JJ, et al. Granulocytic sarcoma in nonleukemic patients. Cancer. 1986;58(12):2697–709.
Minkov M, Grois N, et al. Langerhans cell histiocytosis: histiocyte society evaluation and treatment guidelines. 2009. Retrieved from https://www.histiocytesociety.org/document.doc?id=290. Accessed 23 June 2013.
Miyata T, Masuzawa M, et al. Cutaneous extramedullary hematopoiesis in a patient with idiopathic myelofibrosis. J Dermatol 2008;35(7):456–61.
Mizoguchi M, Kawa Y, et al. Cutaneous extramedullary hematopoiesis in myelofibrosis. J Am Acad Dermatol. 1990;22(2 Pt 2):351–5.
Mohanty SK, Dey P, et al. Cytologic diagnosis of follicular dendritic cell tumor: a diagnostic dilemma. Diagn Cytopathol. 2003;29(6):368–9.
Munn S, Chu AC. Langerhans cell histiocytosis of the skin. Hematol Oncol Clin N Am. 1998;12(2):269–86.
Murakami I, Gogusev J, et al. Detection of molecular cytogenetic aberrations in Langerhans cell histiocytosis of bone. Hum Pathol. 2002;33(5):555–60.
Narvaez D, Kanitakis J, et al. Immunohistochemical study of CD34-positive dendritic cells of human dermis. Am J Dermatopathol. 1996;18(3):283–8.
Neiman RS, Barcos M, et al. Granulocytic sarcoma: a clinicopathologic study of 61 biopsied cases. Cancer. 1981;48(6):1426–37.
Newman B, Hu W, et al. Aggressive histiocytic disorders that can involve the skin. J Am Acad Dermatol. 2007;56(2):302–16.
Ng AP, Lade S, et al. Primary cutaneous CD4+/CD56+ hematodermic neoplasm (blastic NK-cell lymphoma): a report of five cases. Haematologica. 2006;91(1):143–4.
Ngu IW, Sinclair EC, et al. Unusual presentation of granulocytic sarcoma in the breast: a case report and review of the literature. Diagn Cytopathol. 2001;24(1):53–7.
Nguyen TT, Schwartz EJ, et al. Expression of CD163 (hemoglobin scavenger receptor) in normal tissues, lymphomas, carcinomas, and sarcomas is largely restricted to the monocyte/macrophage lineage. Am J Surg Pathol. 2005;29(5):617–24.
O’Malley DP. Benign extramedullary myeloid proliferations. Mod Pathol. 2007;20(4):405–15.
Ohata C, Kawahara K. CD34-reactive myxoid dermal dendrocytoma. Am J Dermatopathol. 2002;24(1):50–3.
Pagerols X, Curc N, et al. Cutaneous extramedullary haematopoiesis associated with blast crisis in myelofibrosis. Clin Exp Dermatol 1998;23(6):296–97.
Park L, Schiltz C, et al. Langerhans cell histiocytosis. J Cutan Med Surg. 2012;16(1):45–9.
Patel BM, Su WP, et al. Cutaneous extramedullary hematopoiesis. J Am Acad Dermatol. 1995;32(5 Pt 1):805–7.
Paydas S, Zorludemir S. Leukaemia cutis and leukaemic vasculitis. Br J Dermatol. 2000;143(4):773–9.
Petrella T, Facchetti F. Tumoral aspects of plasmacytoid dendritic cells: what do we know in 2009? Autoimmunity. 2010;43(3):210–4.
Petrella T, Dalac S, et al. CD4+ CD56+ cutaneous neoplasms: a distinct hematological entity? Groupe Francais d’Etude des Lymphomes Cutanes (GFELC). Am J Surg Pathol. 1999;23(2):137–46.
Petrella T, Comeau MR, et al. ‘Agranular CD4+ CD56+ hematodermic neoplasm’ (blastic NK-cell lymphoma) originates from a population of CD56+ precursor cells related to plasmacytoid monocytes. Am J Surg Pathol. 2002;26(7):852–62.
Petrella T, Meijer CJ, et al. TCL1 and CLA expression in agranular CD4/CD56 hematodermic neoplasms (blastic NK-cell lymphomas) and leukemia cutis. Am J Clin Pathol. 2004;122(2):307–13.
Petrella T, Bagot M, et al. Blastic NK-cell lymphomas (agranular CD4+CD56+ hematodermic neoplasms): a review. Am J Clin Pathol. 2005;123(5):662–75.
Pigozzi B, Bordignon M, et al. Expression of the CD1a molecule in B- and T-lymphoproliferative skin conditions. Oncol Rep. 2006;15(2):347–51.
Pileri SA, Grogan TM, et al. Tumours of histiocytes and accessory dendritic cells: an immunohistochemical approach to classification from the International Lymphoma Study Group based on 61 cases. Histopathology. 2002;41(1):1–29.
Pileri SA, Ascani S, et al. Myeloid sarcoma: clinico-pathologic, phenotypic and cytogenetic analysis of 92 adult patients. Leukemia. 2007;21(2):340–50.
Pileri A, Delfino C, et al. Blastic plasmacytoid dendritic cell neoplasm (BPDCN): the cutaneous sanctuary. G Ital Dermatol Venereol. 2012;147(6):603–8.
Pilichowska ME, Fleming MD, et al. CD4+/CD56+ hematodermic neoplasm (“blastic natural killer cell lymphoma”): neoplastic cells express the immature dendritic cell marker BDCA-2 and produce interferon. Am J Clin Pathol. 2007;128(3):445–53.
Pillay K, Solomon R, et al. Interdigitating dendritic cell sarcoma: a report of four paediatric cases and review of the literature. Histopathology. 2004;44(3):283–91.
Pitcock JA, Reinhard EH, et al. A clinical and pathological study of seventy cases of myelofibrosis. Ann Intern Med. 1962;57:73–84.
Porcu P, Neiman RS, et al. Splenectomy in agnogenic myeloid metaplasia. Blood. 1999;93(6):2132–4.
Rappaport H. Tumors of the hematopoietic system, atlas of tumor pathology, section III, fascicle 8. Washington, DC: Armed Forces Institute of Pathology; 1966. p. 241–3.
Ratzinger G, Burgdorf WH, et al. Indeterminate cell histiocytosis: fact or fiction? J Cutan Pathol. 2005;32(8):552–60.
Reichard KK, Burks EJ, et al. CD4(+) CD56(+) lineage-negative malignancies are rare tumors of plasmacytoid dendritic cells. Am J Surg Pathol. 2005;29(10):1274–83.
Reimer P, Rudiger T, et al. What is CD4+CD56+ malignancy and how should it be treated? Bone Marrow Transplant. 2003;32(7):637–46.
Revenga F, Horndler C, et al. Cutaneous extramedullary hematopoiesis. Int J Dermatol. 2000;39(12):957–8.
Rice GP, Assis LJ, et al. Extramedullary hematopoiesis and spinal cord compression complicating polycythemia rubra vera. Ann Neurol. 1980;7(1):81–4.
Risdall RJ, Dehner LP, et al. Histiocytosis X (Langerhans’ cell histiocytosis). Prognostic role of histopathology. Arch Pathol Lab Med. 1983;107(2):59–63.
Rodriguez Ramirez J, Redondo Martinez E, et al. Idiopathic myelofibrosis with cutaneous extramedullary hematopoiesis. Med Clin (Barc) 1991;97(1):24–6.
Rogalski C, Paasch U, et al. Cutaneous extramedullary hematopoiesis in idiopathic myelofibrosis. Int J Dermatol 2002;41(12):883–84.
Romani N, Lenz A, et al. Cultured human Langerhans cells resemble lymphoid dendritic cells in phenotype and function. J Invest Dermatol. 1989;93(5):600–9.
Romani N, Holzmann S, et al. Langerhans cells – dendritic cells of the epidermis. APMIS. 2003;111(7–8):725–40.
Rosenberg AS, Morgan MB. Cutaneous indeterminate cell histiocytosis: a new spindle cell variant resembling dendritic cell sarcoma. J Cutan Pathol. 2001;28(10):531–7.
Rosenzweig M, Canque B, et al. Human dendritic cell differentiation pathway from CD34+ hematopoietic precursor cells. Blood. 1996;87:535–44.
Ruberto E, Espinola R, et al. Idiopathic myelofibrosis with extramedullary hematopoiesis foci in the skin and testicles. Report of a case. Sangre (Barc) 1995;40(2):157–160.
Salotti JA, Nanduri V, et al. Incidence and clinical features of Langerhans cell histiocytosis in the UK and Ireland. Arch Dis Child. 2009;94(5):376–80.
Sander B, Middel P, et al. Follicular dendritic cell sarcoma of the spleen. Hum Pathol. 2007;38(4):668–72.
Saygin C, Uzunaslan D, et al. Dendritic cell sarcoma: a pooled analysis including 462 cases with presentation of our case series. Crit Rev Oncol Hematol. 2013;88:253–71.
Sen F, Zhang XX, et al. Increased incidence of trisomy 8 in acute myeloid leukemia with skin infiltration (leukemia cutis). Diagn Mol Pathol. 2000;9(4):190–4.
Shao H, Xi L, et al. Clonally related histiocytic/dendritic cell sarcoma and chronic lymphocytic leukemia/small lymphocytic lymphoma: a study of seven cases. Mod Pathol. 2011;24(11):1421–32.
Shia J, Chen W, et al. Extranodal follicular dendritic cell sarcoma: clinical, pathologic, and histogenetic characteristics of an underrecognized disease entity. Virchows Arch. 2006;449(2):148–58.
Shih LY, Lin FC, et al. Cutaneous and pericardial extramedullary hematopoiesis with cardiac tamponade in chronic myeloid leukemia. Am J Clin Pathol. 1988;89(5):693–7.
Sidoroff A, Zelger B, et al. Indeterminate cell histiocytosis–a clinicopathological entity with features of both X- and non-X histiocytosis. Br J Dermatol. 1996;134(3):525–32.
Sontheimer RD, Matsubara T, et al. A macrophage phenotype for a constitutive, class II antigen-expressing, human dermal perivascular dendritic cell. J Invest Dermatol. 1989;93(1):154–9.
Stein SL, Paller AS, et al. Langerhans cell histiocytosis presenting in the neonatal period: a retrospective case series. Arch Pediatr Adolesc Med. 2001;155(7):778–83.
Steiner M, Matthes-Martin S, et al. Improved outcome of treatment-resistant high-risk Langerhans cell histiocytosis after allogeneic stem cell transplantation with reduced-intensity conditioning. Bone Marrow Transplant. 2005;36(3):215–25.
Steinman RM. Some interfaces of dendritic cell biology. APMIS. 2003;111(7–8):675–97.
Steinman RM, Pack M, et al. Dendritic cells in the T-cell areas of lymphoid organs. Immunol Rev. 1997;156:25–37.
Stockschlaeder M, Sucker C. Adult Langerhans cell histiocytosis. Eur J Haematol. 2006;76(5):363–8.
Su WP. Clinical, histopathologic, and immunohistochemical correlations in leukemia cutis. Semin Dermatol. 1994;13(3):223–30.
Sun X, Chang KC, et al. Epidermal growth factor receptor expression in follicular dendritic cells: a shared feature of follicular dendritic cell sarcoma and Castleman’s disease. Hum Pathol. 2003;34(9):835–40.
Szomor A, Passweg JR, et al. Myeloid leukemia and myelodysplastic syndrome relapsing as granulocytic sarcoma (chloroma) after allogeneic bone marrow transplantation. Ann Hematol. 1997;75(5–6):239–41.
Taverna JA, Stefanato CM, et al. Adult cutaneous Langerhans cell histiocytosis responsive to topical imiquimod. J Am Acad Dermatol. 2006;54(5):911–3.
Tecchio C, Colato C, et al. Plasmacytoid dendritic cell leukemia: a rapidly evolving disease presenting with skin lesions sensitive to radiotherapy plus hyperthermia. Oncologist. 2009;14(12):1205–8.
Teunissen MB, Wormmeester J, et al. Human epidermal Langerhans cells undergo profound morphologic and phenotypical changes during in vitro culture. J Invest Dermatol. 1990;94(2):166–73.
Tew JG, Kosco MH, et al. Follicular dendritic cells as accessory cells. Immunol Rev. 1990;117:185–211.
Turner RR, Wood GS, et al. Histiocytic malignancies. Morphologic, immunologic, and enzymatic heterogeneity. Am J Surg Pathol. 1984;8(7):485–500.
Vargas H, Mouzakes J, et al. Follicular dendritic cell tumor: an aggressive head and neck tumor. Am J Otolaryngol. 2002;23(2):93–8.
Vasef MA, Zaatari GS, et al. Dendritic cell tumors associated with low-grade B-cell malignancies. Report of three cases. Am J Clin Pathol. 1995;104(6):696–701.
Vener C, Soligo D, et al. Indeterminate cell histiocytosis in association with later occurrence of acute myeloblastic leukaemia. Br J Dermatol. 2007;156(6):1357–61.
Vogel CA, Aughenbaugh W, et al. Excimer laser as adjuvant therapy for adult cutaneous Langerhans cell histiocytosis. Arch Dermatol. 2008;144(10):1287–90.
Wagner G, Fenchel K, et al. Leukemia cutis – epidemiology, clinical presentation, and differential diagnoses. J Dtsch Dermatol Ges. 2012;10(1):27–36.
Wang J, Bu DF, et al. Autoantibody production from a thymoma and a follicular dendritic cell sarcoma associated with paraneoplastic pemphigus. Br J Dermatol. 2005;153(3):558–64.
Ward HP, Block MH. The natural history of agnogenic myeloid metaplasia (AMM) and a critical evaluation of its relationship with the myeloproliferative syndrome. Medicine (Baltimore). 1971;50(5):357–420.
Weiss LM, Berry GJ, et al. Spindle cell neoplasms of lymph nodes of probable reticulum cell lineage. True reticulum cell sarcoma? Am J Surg Pathol. 1990;14(5):405–14.
Weiss T, Weber L, et al. Solitary cutaneous dendritic cell tumor in a child: role of dendritic cell markers for the diagnosis of skin Langerhans cell histiocytosis. J Am Acad Dermatol. 2005;53(5):838–44.
Wells GC. The pathology of adult type Letterer-Siwe disease. Clin Exp Dermatol. 1979;4(4):407–12.
Wheller L, Carman N, et al. Unilesional self-limited Langerhans cell histiocytosis: a case report and review of the literature. J Cutan Pathol. 2013;40(6):595–9.
Wiernik PH, Serpick AA. Granulocytic sarcoma (chloroma). Blood. 1970;35(3):361–9.
Willemze R, Jaffe ES, et al. WHO-EORTC classification for cutaneous lymphomas. Blood. 2005;105(10):3768–85.
Willman CL, Busque L, et al. Langerhans’-cell histiocytosis (histiocytosis X) – a clonal proliferative disease. N Engl J Med. 1994;331(3):154–60.
Wollenberg A, Burgdorf WH, et al. Long-lasting “christmas tree rash” in an adolescent: isotopic response of indeterminate cell histiocytosis in pityriasis rosea? Acta Derm Venereol. 2002;82(4):288–91.
Wong E, Holden CA, et al. Histiocytosis X presenting as intertrigo and responding to topical nitrogen mustard. Clin Exp Dermatol. 1986;11(2):183–7.
Wong TY, Suster S, et al. Histologic spectrum of cutaneous involvement in patients with myelogenous leukemia including the neutrophilic dermatoses. Int J Dermatol. 1995;34(5):323–9.
Wood GS, Turner RR, et al. Human dendritic cells and macrophages. In situ immunophenotypic definition of subsets that exhibit specific morphologic and microenvironmental characteristics. Am J Pathol. 1985;119(1):73–82.
Wu L, Liu YJ. Development of dendritic-cell lineages. Immunity. 2007;26(6):741–50.
Wu J, Qin D, et al. Follicular dendritic cell-derived antigen and accessory activity in initiation of memory IgG responses in vitro. J Immunol. 1996;157(8):3404–11.
Wu Q, Liu C, et al. Interdigitating dendritic cell sarcoma involving bone marrow in a liver transplant recipient. Transplant Proc. 2010;42(5):1963–6.
Ylagan LR, Bartlett NL, et al. Interdigitating dendritic reticulum cell tumor of lymph nodes: case report with differential diagnostic considerations. Diagn Cytopathol. 2003;28(5):278–81.
Yousem SA, Colby TV, et al. Pulmonary Langerhans’ cell histiocytosis: molecular analysis of clonality. Am J Surg Pathol. 2001;25(5):630–6.
Yu RC, Chu C, et al. Clonal proliferation of Langerhans cells in Langerhans cell histiocytosis. Lancet. 1994;343(8900):767–8.
Zachary CB, MacDonald DM. Hand-Schuller-Christian disease with secondary cutaneous involvement. Clin Exp Dermatol. 1983;8(2):177–83.
Zunino-Goutorbe C, Eschard C, et al. Congenital solitary histiocytoma: a variant of Hashimoto-Pritzker histiocytosis. A retrospective study of 8 cases. Dermatology. 2008;216(2):118–24.
Author information
Authors and Affiliations
Corresponding author
Editor information
Editors and Affiliations
Rights and permissions
Copyright information
© 2014 Springer Science+Business Media New York
About this chapter
Cite this chapter
Dalia, S., Sokol, L., Cualing, H.D. (2014). Cutaneous Myelomonocytic Infiltrates. In: Cualing, H., Kadin, M., Hoang, M., Morgan, M. (eds) Cutaneous Hematopathology. Springer, New York, NY. https://doi.org/10.1007/978-1-4939-0950-6_16
Download citation
DOI: https://doi.org/10.1007/978-1-4939-0950-6_16
Published:
Publisher Name: Springer, New York, NY
Print ISBN: 978-1-4939-0949-0
Online ISBN: 978-1-4939-0950-6
eBook Packages: MedicineMedicine (R0)