Primary Effusion Lymphoma

General: Primary effusion lymphoma is a rare type of large B-cell lymphoma that occurs most frequently in HIV-infected patients. It usually presents in patients as an effusion in the absence of lymphadenopathy or mass. Pericardial, pleural, or peritoneal cavities may be involved. The lymphoma is highly associated with HHV-8 and most, but not all, cases are EBV-positive. It is an aggressive lymphoma with short survival.7778

Pathology: On Wright stain the cells are pleomor-phic. Some cells may have features of immunoblasts with large nuclei and prominent nucleoli. Others are more anaplastic with multilobated nuclei and/or mult-inucleation. The cytoplasm is deeply basophilic. Vacuoles may be present. Histologic sections, when a mass is present, show similar cells.7778

Immunophenotype: The cells are usually negative for pan B-cell antigens such as CD19 and CD20 but show expression of plasmacytic differentiation such as CD38 and CD138. CD30 is often expressed as is epithelial membrane antigen. Surface and cytoplasmic immunoglobulin are not detectable.77,78

Molecular genetics: IGH is rearranged, as expected. The HHV-8 viral genome encodes for several genes that may be involved in lymphomagenesis such as cyclin genes, cytokines, and molecules important in regulating apoptosis and nuclear transcription factors.79-82

0 0

Post a comment