Lymphangioma-like Kaposi sarcoma: case report.

Kaposi sarcoma (KS) is a multifocal vascular disease with uncertain histogenesis. It is characterized by clinical and histologic polymorphism. The "lymphangioma-like" variant is very uncommon, accounting for less than 5% of all cases. We report the case of a 76-year-old woman, HIV negative, with a 4-year history of classic Kaposi sarcoma treated with cryotherapy who developed new bullous lesions on her lower extremities. Biopsy revealed histologic findings of lymphangioma-like KS (LLKS), together with areas of classic KS; HHV-8 staining was positive. Diagnosis of LLKS was made and the patient was proposed for radiotherapy. The lymphangioma-like Kaposi sarcoma is a rare morphologic expression of KS characterized by dilated and bizarrely shaped vascular channels lined by flattened endothelium permeating the dermis. "Bulla-like" lesions have been considered as a clinical hallmark of this variant. Its histologic appearance suggests a lymphatic origin of KS and it may resemble other vascular tumors. Findings of areas of typical KS and positive staining for HHV-8 may help to make a definitive diagnosis.