Microvenular hemangioma

Microvenular hemangioma is an acquired benign vascular tumor that presents as an asymptomatic, slowly growing, 0.5- to 2.0 cm reddish lesion on the forearms or other sites of young to middle-aged adults.^[2] The cause of microvenular hemangioma is unknown, however it has been associated with immunosuppression.

Microvenular hemangioma
Other names	Microcapillary hemangioma[1]
Specialty	Oncology

Signs and symptoms

Microvenular hemangioma appears as slow-growing, frequently numerous lesions, erythematous, violaceous, or moderately pruriginous macules, papules, or nodules without any symptoms.^[3] They usually appear on the forearm. There have also been reports of lesions on the soles of the feet, forehead, legs, and chest.^[4]

Causes

Although the exact cause of microvenular hemangioma is uncertain, it has been found in certain instances during pregnancy or after changes in hormonal contraception.^[5] In certain circumstances, imbalanced sex hormones could potentially be the cause.^[6] Microvenular hemangioma has also been associated with immunosuppression.^[7]

Diagnosis

Multiple distinct red globules are seen under a microscope, and a finely pigmented network is seen around the periphery.^[8] Histologically, microvenular hemangioma is made up of venules with thin walls that branch erratically and have barely noticeable vascular lumina. The dermis's collagen bundles are thickened.^[6] Pericytes envelop the endothelial cells,^[9] which can exhibit a combination of plump and flat cells without pleomorphism or mitotic patterns.^[10]

Immunohistochemically, an microvenular hemangioma's endothelial cells show positive staining for CD31, CD34, and factor VIII, while its pericytes show positive staining for SMA.^[8][11] However, neither cell shows positive staining for podoplanin.^[12]

The differential diagnosis for microvenular hemangioma includes acquired (tufted) angioma, Kaposi sarcoma, Kaposiform hemangioendothelioma, and sclerosing hemangioma.^[13]

Treatment

The treatment for microvenular hemangioma is surgical excision.^[13]

See also

• Hemangioma
• List of cutaneous conditions