[Misleading Kaposi's sarcoma: usefulness of anti HHV-8 immunostaining]

We report two cases of early Kaposi's sarcoma illustrating the risk of misdiagnosis. Both lesions showed histological features and clinical aspects that mimicked lymphangioendothelioma. The diagnosis of lymphangioma-like Kaposi's sarcoma was not made until a few years later, after the lesions had become more extensive and bilateral. Because of this evolution which is uncommon for a lymphangioendothelioma, immunohistochemical staining with anti-HHV8 antibody was done, and was positive in successive biopsies of our two patients. These results reveal that these vascular lesions had been Kaposi's sarcomas of the lymphangioma-like type since the beginning. In conclusion, it seems essential to search for HHV8 within endothelial cells of any vascular lesion mimicking lymphangioendothelioma or any other vascular proliferation difficult to classify. These results lead us to question whether lymphangioendothelioma is a real entity.