Intravascular large cell lymphoma: a patient with asymptomatic purpuric patches and a chronic clinical course.

Intravascular large cell lymphoma (malignant angioendotheliomatosis) is a rare, multifocal, intravascular neoplasm of lymphoid cells that preferentially involves the vasculature of the skin and central nervous system. We describe a 54-year-old man with asymptomatic purpuric patches on the lower extremities for 10 years duration and a more recent lesion on the right arm. A biopsy specimen showed intravascular collections of tumor cells with irregular nuclear contours and prominent nucleoli. These cells were leukocyte common antigen (CD45), CD20, and CDW75 positive, but CD3, CD43, CD45RO, and cytokeratin negative. Polymerase chain reaction analysis of the skin for immunoglobulin heavy chain gene rearrangement detected a clonal population of B cells, supporting the diagnosis of a B-cell lymphoma. Peripheral blood showed no abnormal circulating cells. This case of malignant angioendotheliomatosis is unusual for its prolonged clinical course and presence of purpuric patches.