Abstract
Definition: Sarcomas composed of myofibroblasts.
Access provided by Autonomous University of Puebla. Download chapter PDF
Similar content being viewed by others
Keywords
- Myogenic Differentiation
- Myofibroblastic Differentiation
- Occasional Case
- Deep Soft Tissue
- Atypical Mitosis
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.
Definition: Sarcomas composed of myofibroblasts.
Myofibroblastic sarcomas display a range of differentiation. Low-grade myofibroblastic sarcoma is identified as a specific entity in the WHO 2013 classification, while the definition of high-grade myofibroblastic sarcoma is not well established. There is evidence that myofibroblastic differentiation in pleomorphic sarcomas is associated with a more aggressive behavior.
Epidemiology: Low-grade myofibroblastic sarcomas occur predominantly in adult patients (age range: 4–75 years, mean 38), while high-grade myofibroblastic sarcomas can also occur in children. There is a slight male predominance.
Location: Low-grade myofibroblastic sarcomas most commonly occur in the head and neck region, including the oral cavity, pharynx and parapharyngeal regions, and proximal extremities and trunk; occasional cases can occur in the abdomen or pelvis. They usually arise in the deep soft tissues, but cases have been seen in the subcutis and submucosa. Visceral lesions are rare. Cases have also been described in bone, including maxilla, mandible, femur, and ilium. High-grade myofibroblastic sarcomas arise in deep soft tissues, predominantly in lower limbs and trunk, with occasional cases in head and neck.
Clinical and Imaging: Enlarging painless mass, very often with infiltrative margins. High-grade sarcomas with hemorrhage and necrosis are heterogeneous at MRI.
Histopathology: Grossly, low-grade myofibroblastic sarcomas are firm with a pale fibrous-appearing cut surface, ill-defined infiltrative margins, or sometimes with pushing margins. High-grade myofibroblastic sarcomas are large solid tumors with hemorrhage and necrosis. Histologically, low-grade myofibroblastic sarcomas are characterized by a proliferation of spindle cells arranged in a fascicular or in a storiform pattern. The neoplastic cells show tapered fusiform elongated to wavy nuclei with discernible eosinophilic cytoplasm. Sometimes the nuclei are rounded and vesicular with small punctuated nucleoli. There is at least focally moderate nuclear atypia. The margins are predominantly infiltrative, with separation rather than destruction of skeletal muscle bundles. Mitotic activity is variable but atypical mitoses are rare. Stroma is often minimal and can be variably collagenous. High-grade myofibroblastic sarcomas are composed of pleomorphic, spindle, or epithelioid cells arranged in a fascicular or in a storiform growth pattern, with scattered atypical mitotic figures. Both low- and high-grade myofibroblastic sarcomas show variable positivity for actins and/or desmin. Calponin and CD34 can be positive. EMA, S100, beta-catenin, and caldesmon are negative. Ultrastructure is the gold standard in defining normal myofibroblasts which are distinguished from smooth muscle cells by fibronectin fibril and fibronexus junctions, which are considered the most characteristic ultrastructural markers of myofibroblasts. Fibronexus, a cell-to-matrix junction, first described and designated by Singer in 1979, is a unit composed of fibronectin and 5 nm microfilaments that converge at the cell surface. It is not perfectly clear whether these features are always present in myofibroblastic sarcomas.
Course and Staging: About 33 % of low-grade myofibroblastic sarcomas locally recur, especially after incomplete excision. Metastases have been reported in approximately 10 % of cases. Progression to high-grade sarcoma has been documented. High-grade myofibroblastic sarcomas recur in 33 % of cases with metastases in over 70 %. These tumors, like the other pleomorphic sarcomas with myogenic differentiation, have a worse outcome than undifferentiated sarcomas.
Treatment: Low-grade myofibroblastic sarcomas are best managed by wide surgical excision and long-term follow-up to detect possible late metastases. High-grade myofibroblastic sarcomas should be managed by excision with wide margins and adjuvant radiation therapy and/or systemic chemotherapy.
FormalPara Immunohistochemical PanelVIM | + |
MS act | ± |
Smooth M act | ± |
Desmin | ± |
Caldesmon | − |
Calponin | + |
Selected Bibliography
Eyden B, Banerjee SS, Shenjere P, Fisher C (2009) The myofibroblast and its tumours. J Clin Pathol 62(3):236–249. Review
Fisher C (2004) Myofibroblastic malignancies. Adv Anat Pathol 11(4):190–201. Review
Fletcher CD (1998) Myofibroblastic tumours: an update. Verh Dtsch Ges Pathol 82:75–82. Review
Fletcher CDM, Bridge JA, Hogendoorn PCW, Mertens F (eds) (2013) WHO classification of tumors of soft tissue and bone, 4th edn. International Agency for Research on Cancer, Lyon
Meng GZ, Zhang HY, Zhang Z, Wei B, Bu H (2009) Myofibroblastic sarcoma vs nodular fasciitis: a comparative study of chromosomal imbalances. Am J Clin Pathol 131(5):701–709
Perez-Montiel MD, Plaza JA, Dominguez-Malagon H, Suster S (2006) Differential expression of smooth muscle myosin, smooth muscle actin, h-caldesmon, and calponin in the diagnosis of myofibroblastic and smooth muscle lesions of skin and soft tissue. Am J Dermatopathol 28(2):105–111
Author information
Authors and Affiliations
Corresponding author
Editor information
Editors and Affiliations
Rights and permissions
Copyright information
© 2014 Springer International Publishing Switzerland
About this chapter
Cite this chapter
Gambarotti, M. (2014). Myofibroblastic Sarcoma. In: Picci, P., Manfrini, M., Fabbri, N., Gambarotti, M., Vanel, D. (eds) Atlas of Musculoskeletal Tumors and Tumorlike Lesions. Springer, Cham. https://doi.org/10.1007/978-3-319-01748-8_73
Download citation
DOI: https://doi.org/10.1007/978-3-319-01748-8_73
Published:
Publisher Name: Springer, Cham
Print ISBN: 978-3-319-01747-1
Online ISBN: 978-3-319-01748-8
eBook Packages: MedicineMedicine (R0)