Lymphangioma-like variant of Kaposi's sarcoma: clinicopathologic study of seven cases with review of the literature.

The clinical and pathological features of seven cases of lymphangioma-like Kaposi's sarcoma (KS) are reported. As with the other subtypes of KS, the lymphangioma-like variant occurs more often in men aged 59-80 years. Clinically, the lesion appears intermingled with the classical forms of KS, but a "bulla-like" appearance recognized in seven of 13 cases has been considered as a clinical hallmark of this variant. Although occasional cases have shown aggressive behavior, the most frequent clinical course is slowly progressive with localized or diffuse involvement of lower limbs. The histological pattern, characterized by permeation of dermal collagen by labyrinthine vascular channels lined by a flattened endothelium, must be differentiated from spindle cell hemangioendothelioma, low-grade angiosarcoma, targetoid hemosiderotic hemangioma, and benign lymphangioendothelioma.