Epstein-Barr virus-associated intravascular lymphomatosis within Kaposi's sarcoma in an AIDS patient

Intravascular lymphomatosis (IL) is an unusual neoplasm characterized by mu ltifocal proliferation of lymphoma cells exclusively within the blood vesse ls. We report here a patient with acquired immunodeficiency syndrome (AIDS) and disseminated Kaposi's sarcoma. A 233-bp amplification product of HHV-8 was detected in the DNA extracted from specimens of Kaposi's sarcoma at di fferent sites by polymerase chain reaction (PCR). At autopsy, the vessels w ithin the Kaposi's sarcoma were dilated and filled with atypical large mono nuclear cells. No such feature was seen in the vessels of non-Kaposi's sarc omatous regions. Immunohistochemically, the spindle cells of Kaposi's sarco ma were positive for CD31 (endothelial cell marker). The intravascular tumo r cells were positive for CD45 (leukocyte common antigen) but negative for others, including chloroacetate esterase, CD45-RO (UCHL-1, Pan-T), CD3, CD4 3, CD20 (L26 Pan-B), CD30 (Ki-1), immunoglobulin heavy chains and light cha ins, CD56 (natural killer cell antigen), and CD31. Monoclonal rearrangement of immunoglobulin heavy chain gene was detected in the DNA extracts from f resh tissue of Kaposi's sarcoma by PCR, which indicated that the lymphoma c ells within the Kaposi's sarcoma were of monoclonal B cell origin. In situ hybridization revealed that EBER-1 transcripts were present in the lymphoma cells of IL but not in the spindle cells of Kaposi's sarcoma. To the autho rs' best knowledge, this is the first instance of IL in an AIDS patient wit h direct evidence of EBV association.