[Systemic proliferative angioendotheliomatosis: a cutaneous manifestation of malignant B-cell lymphomas. Histologic and immunohistologic studies of two cases].

Angioendotheliomatosis proliferans systemisata (AEPS) is a rare disease entity characterized by a predominantly intravascular proliferation of tumour cells. Two forms of AEPS are differentiated: a very rare, benign and self-limiting form, which is endothelial in origin, and a more common, malignant form, which is an angiotropic intravascular malignant B-cell lymphoma. Histological and immunohistological investigations of the malignant form of AEPS are presented: In a 69-year-old woman cutaneous lesions appeared 5 months before the diagnosis of B-immunoblastic lymphoma. In a 57-year-old woman lesions were observed simultaneously with the relapse of a high-grade malignant B-cell lymphoma. Immunohistological identification of the proliferating cell type made diagnosis of intravascular B-cell lymphoma possible in paraffin-embedded biopsies.