Diffuse large B cell lymphoma CD5-positive arising in an immune deficiency and immune dysregulation setting: A case report and brief review of the literature

Abstract

Rationale: In the era of antiretroviral therapy, lymphoma is the primary cause of cancer-related death among human immunodeficiency virus (HIV)-infected people and the most prevalent and aggressive non-Hodgkin lymphoma is diffuse large B cell lymphoma, which usually has an aggressive clinical course. CD5-positive diffuse large B cell lymphoma (DLBCL) is an insufficiently studied, relatively new entity, which accounts for 5% to 10% of the DLBCL population. The current study presents the clinicopathological features, diagnostic approach, and clinical outcomes of this HIV-related lymphoma and highlights the importance of the early diagnosis of CD5-positive DLBCL. Patient concerns: We present a case of a 30-year-old male patient, with a medical history of HIV-positive serology and antiviral treatment, presenting with diffuse abdominal pain and symptoms related to obstruction or perforation, followed by exploratory laparotomy and surgical resection of the small intestine with other areas of involvement. The surgical specimen was morphologically evaluated and immunohistochemical stained. Diagnoses and Interventions: Histopathologic examination revealed a diffuse neoplastic proliferation of large B lymphocytes within the small intestine, lacking features of other defined types of large B cell lymphoma. The diagnosis of CD5-positive DLBCL subtype was made after immunostaining with twelve monoclonal antibodies (CD3, CD5, CD10, CD20, CD23, CD30, CD68, Cyclin D1, MUM1, Bcl2, Bcl6, and Ki-67). The expression profile of immunohistochemical markers (CD10, Bcl6, and MUM1) established the cell of origin of this case of DLBCL by using the Hans algorithm. Lessons: The current report highlights the importance of early diagnosis of CD5-positive DLBCL because of its poor prognosis and calls attention to the critical importance to identify immunodeficiencies because doing so affects the types of treatments available. Although cell-of-origin is useful for predicting outcomes, the germinal center B cell like and activated-B cell like subtypes remain heterogeneous, with better, and worse prognostic subsets within each group.