Keywords

There is a fundamental conceptual division between hemangiomas and vascular malformations—the former being proliferating tumors and the latter developmental errors.

1 Pathology

Infantile Hemangiomas

  1. 1.

    Mutation in a primitive stem cell is responsible for developing blood vessels.

  2. 2.

    Hemangioma is a model of pure, unopposed angiogenesis with a common expression of immunohistochemical markers including glut-1, Fcy RII, and Lewis Y antigen.

  3. 3.

    Possible derivation from or sharing a common precursor with placenta.

  4. 4.

    Angiogenic peptides.

    1. (a)

      Proliferating phase—expression of vascular endothelial growth factor (VEGF), basic fibroblast growth factor (bFGF), and type IV collagenase.

    2. (b)

      Involution phase—tissue inhibitor of metalloproteinases (TIMP-I) and mast cell-secreted modulators.

Vascular malformations are usually sporadic but can also be inherited in a family as an autosomal dominant trait. They are a manifestation of many different genetic syndromes that have a variety of inheritance patterns and chances for reoccurrence, depending on the specific syndrome.

2 Hemangioma Versus Vascular Malformation

Hemangiomas and vascular malformations may have nothing in common pathologically except a somewhat similar appearance. Vascular anomalies manifest with a very wide clinical spectrum of lesions ranging from small skin discoloration to very large life-threatening conditions.

Table 62.1 illustrates key clinical differences between these entities though in practice there can be difficulties in their separation (e.g., liver hemangiomas/vascular anomalies).

Table 62.1 Biological classification
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3 Specific Examples (Table 62.2)

3.1 Kasabach-Merritt Syndrome

Characterized by the combination of a rapidly growing vascular tumor, thrombocytopenia, microangiopathic hemolytic anemia and consumptive coagulopathy. The blood clotting disorder results from platelets and other clotting factors from the blood being “used up” within the tumor. Seen in extremities and some viscera (e.g., liver). There is a high mortality rate in untreated cases. Treatment may be a combination of surgical excision, interferon, systemic corticosteroids.

Table 62.2 Summary of clinical features
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3.2 Klippel-Trenaunay Syndrome (KTS)

Characterized by soft tissue hypertrophy and bony overgrowth of the extremity (usually single and lower limb) with PWS. Overgrowth is not present at birth and significant limb length discrepancy is possible later with prominent hypertrophy of the foot and toes. No CNS or visceral anomalies, Treatment: premature epiphyseal closure of longer leg, Surgical debulking not usually feasible.

3.3 Parkes Weber Syndrome (PWS)

Similar to KTS except that an arteriovenous malformation (AVM) occurs in association with a cutaneous capillary malformation and skeletal or soft tissue hypertrophy.

3.4 Sturge-Weber Syndrome (SWS)

Facial port-wine stain in the region of the trigeminal cranial nerve. V1 lesions—may cause seizures, mental retardation. Look for “railroad track” calcifications and eye lesions (ipsilateral choroidal angiomatosis, glaucoma can be seen with V2 lesions involving eyelid).

4 Investigations

Most vascular birthmarks can be diagnosed clinically without imaging studies/biopsy.

  • Laboratory—FBC, C-RP, coagulation parameters, genetic studies.

  • Imaging

    • Ultrasonography and Doppler US examinations are the best initially.

  • MR scan—usually needed in most symptomatic patients to confirm the suspected diagnosis and to evaluate the extent of the lesion (hemangioma, arteriovenous malformation or AVM, venous malformation, lymphatic malformation, cystic hygroma, etc.). In addition to making the diagnosis, MRI plays a major role in decision-making regarding how these lesions need to be treated surgery versus embolization/sclerotherapy.

  • Magnetic Resonance Angiography (MRA) and Magnetic Resonance Venography (MRV) can supply additional information on vascularity.

  • CT scan and X-ray (phleboliths, calcification) imaging have a limited role in vascular anomalies/birthmarks. On the other hand, new multi-detector CT scanners may be used.

  • CT angiography in selected patients, particularly in patients with high flow vascular birthmarks (AVM, hemangioma, arteriovenous fistula).

  • Biopsy: Rarely if malignancy cannot be excluded, e. g., infantile fibrosarcoma, teratoma, siloblastoma, and plexiform neurofibromatosis

5 Treatment

Treatment for hemangiomas depends upon their size, location, and severity.

  • Conservative treatment is usually recommended for small, noninvasive hemangiomas, since they will become smaller (involute) on their own. However, hemangiomas that cause bleeding problems, feeding or breathing difficulties, growth disturbances, or impairment of vision may require multimodality treatment.

Options include the following:

  • Medical Treatment

    • Steroid therapy: Topical, intralesional triamcinolone, or systemic oral steroids. For example, prednisolone 3, 2.5, 1.2, 0.6, 0.3 mg/kg from week 1–5 and maybe repeated up to 6–12 months. Rebound is well known.

    • Propranolol: 2–3 mg/kg 2–3 times a day but has side effects of hypoglycemia, sleepiness, GORD worsening, irritable airways and bradycardia need monitoring.

    • Antiangiogenic drugs and immunomodulation in selected cases.

  • Laser therapy

    • CT/Fluoroscopy guided—different lasers can be used for treatment.

    • Nd:YAG laser photocoagulation—particularly effective because of its deep penetration into tissue.

  • Interventional radiology—embolization of the blood vessels in internal lesions.

  • Surgical removal—large and/or life-threatening lesions after evaluation by a multidisciplinary team of specialists.

Treatment for vascular malformations depends upon the type of malformation. Each type of malformation is treated differently; the importance of obtaining a correct diagnosis is extremely important and often difficult. Most often, a combination of these various treatments is used for effective management of the lesion.

  • Laser surgery

    • Usually effective for capillary malformations or port wine stains, which tend to be flat, violet, or red patches on the face.

  • Sclerotherapy

    • Venous malformations are usually treated by direct injection of a sclerosing medication, which causes clotting of the channels. Sclerosing agents may include: ethanol (alcohol), Sodium Tetradecyl Sulfate (STD—Sotradesol™), doxycycline, and OK 432.

  • Embolization

    • Arterial malformations-blood flow into malformation is blocked by injecting material near the lesion. Embolization is the procedure in which abnormal vessels that are doing more harm than good are closed off with various substances (e.g., alcohol, glue, and coil). Various materials may be used, depending on whether vessel occlusion is to be temporary or permanent, or whether large or small vessels are being treated.

  • Surgical removal of the lesion

    • For cosmetic/functional or complications.

6 Complications

Several complications have been described including alarming hemangioma involving vital/important structures: eye, larynx, ear, and distal extremities. DIC and coagulopathy with platelet trapping can occur. Cosmetically sensitive regions are nose, lip, eye, and ear might need early intervention. Usual complications include bleeding, infection, ulceration, calcification (microthrombi), thrombosis with rapidly growing lesions, hypopigmentation, and the residual lesions. Each modality of treatment has its own complications as well.