We report a 63-year-old man with violaceous nummular patches on the trunk. Histopathologic studies were consistent with a diagnosis of malignant angioendotheliomatosis or angiotropic lymphoma. Immunohistochemical study of skin was positive for UCHL-1 antigen and leukocyte common antigen and negative for L-26, Ulex europaeus lectin I, vimentin, cytokeratin, and epithelial membrane antigen. Ultrastructural study ruled out an endothelial origin of the neoplastic cells. These data confirmed the diagnosis of malignant proliferative angioendotheliomatosis. Five years before, a soft tissue lymphoma had been excised. This is an unusual case of malignant angioendotheliomatosis for the following two reasons: (1) a previous association with a soft tissue lymphoma and (2) the rarely described T immunophenotype of neoplastic lymphoid cells.Le texte complet de cet article est disponible en PDF.