Vascular tumors

Abstract

Cutaneous vascular tumors show different degrees of malignancy: benign (hemangiomas), borderline/low-grade malignant (hemangioendotheliomas) and malignant (angiosarcomas): they are usually very aggressive and have an unfavorable prognosis. Kaposi's sarcoma has a peculiar biology: this tumor is caused by human herpesvirus type 8 infection and shows pronounced growth, especially under immunosuppression. Vascular proliferations with lymphatic endothelial cells, previously referred to as lymphangiomas, are subsumed under lymphatic vascular malformations. The same applies to glomangioma, which has been reclassified as glomuvenous malformation. Angiosarcomas arise either de novo (primary angiosarcoma) or as secondary tumors after irradiation or in the setting of chronic lymphedema (secondary angiosarcoma). MYC amplification, which can be detected cytogenetically (fluorescence in situ hybridization) and by immunohistochemistry, is a characteristic hallmark of radiation- and lymphedema-associated secondary angiosarcoma. Angiosarcomas of the head and neck region often begin with uncharacteristic clinical symptoms, which are mostly misinterpreted as inflammatory diseases of the scalp and facial skin.