HIV, Intussusception, and a Hidden Malignancy Masquerading Abdominal Tuberculosis: Diffuse Large B-Cell Lymphoma Unveiled

Diffuse large B-cell lymphoma (DLBCL) is a common aggressive non-Hodgkin lymphoma, frequently seen in immunocompromised individuals. This report details the case of a 40-year-old HIV-positive female admitted for abdominal pain, vomiting, and imaging suggestive of disseminated tuberculosis, who was ultimately diagnosed with DLBCL of the ileum complicated by intussusception. Initial investigations revealed anemia and thrombocytosis. Contrast-enhanced CT showed multiple necrotic granulomatous lesions and jejunoileal intussusception, mimicking tuberculosis. Surgical exploration and resection of the intussuscepted ileal segment revealed a polypoidal tumor. Histopathological examination indicated a diffuse proliferation of lymphoma cells with plasmacytoid morphology. Immunohistochemistry confirmed DLBCL (germinal center B-cell subtype), with tumor cells positive for Oct-2, CD20, PAX5, BCL-6, and CD10 and negative for CD38, CD138, and MUM1. This case highlights the diagnostic challenges in differentiating intestinal DLBCL from infectious and inflammatory conditions such as tuberculosis in HIV-positive patients. It underscores the commentative role of biopsy and immunohistochemistry in accurate diagnosis and timely initiation of appropriate therapy, ultimately improving patient outcomes.