Colorectal lymphoma in the setting of HIV: case report and review of the literature.

The incidence of Burkitt's lymphoma, a rare and aggressive form of non-Hodgkin's lymphoma, remains unaffected by immune reconstitution in HIV-infected individuals. We report a case of a 45-year-old patient with HIV on highly active antiretroviral therapy (HAART) who presented with symptoms of rectal pain. After two misdiagnoses, a computed tomography (CT) scan showed marked rectal wall thickening and lymphadenopathy. A flexible sigmoidoscopy with biopsy of the rectum and peripheral blood smear with bone marrow examination revealed immunophenotypic and cytogenic findings diagnostic of Burkitt's lymphoma of the rectum. The patient has initiated an intensive chemotherapy regimen with good clinical response. There have been significantly fewer reports of colorectal lymphomas in the HAART era, although HIV-infected patients are still at higher risk for developing uncommon manifestations of these types of malignancies.