Gastrointestinal Tract Plasmablastic Lymphoma in HIV-Infected Adults: A Histopathological Review

Background.: Plasmablastic lymphoma (PBL) is an aggressive B-cell lymphoma that is characterized by the expression of plasma cell antigens and loss of pan B-cell antigens. The neoplasm is extensively reported in the oral cavity and anorectal region but rarely in the gastrointestinal tract, where only isolated case reports and small case series have been reported. In the current study, morphologic, immunohistochemical, and molecular features of 17 cases of gastrointestinal tract PBL were reviewed. Methods.: Ten-year retrospective study that reappraised the histomorphological and immunophenotypical profiles of HIV-associated PBLs in the gastrointestinal tract. Results.: The mean age of the study patients was 41 years with a 3:1 ratio of males to females. The most common site of tumor origin was the small intestine (42%), followed by the stomach (29%) and the colon (29%). Majority of the cases showed a predominant diffuse (82%) growth pattern. Immunoblasts and plasmablasts were observed in all cases. Plasmacytic differentiation was seen in 5 (29%) cases. Additional observations not previously described or emphasized in literature includes pseudo-alveolar growth pattern, centroblast-predominance, multinucleated giant cells, and clear cell change. Immunohistochemistry revealed absence of pan B-cell antigens and expression of plasma cell antigens in all cases. Epstein-Barr virus–encoded RNA was expressed in 53% of the cases. Conclusions.: This study highlights the spectrum of histopathological features seen in gastrointestinal tract PBLs. Awareness of this entity and its histopathological features in the gastrointestinal tract is essential for making a timely and accurate diagnosis and improving patient outcomes.