HIV-Negative Plasmablastic Lymphoma: Not in the Mouth

Plasmablastic lymphoma (PBL) is an aggressive variant of non-Hodgkin lymphoma initially reported in the oral cavity of HIV-positive individuals. Since its original description, several cases have been reported in patients who do not have HIV infection. However, despite its recognition as a distinct subtype of diffuse large B-cell lymphoma several years ago, comprehensive reviews of this entity are lacking. A MEDLINE search through June 2010 was performed to identify cases with a pathologic diagnosis of HIV-negative PBL based on morphology and minimal immunohistochemical criteria. Our study included a total of 76 cases. The median age was 57 years (range, 1 to 90 years) with a male-to-female ratio of 1.7. Seventy-four percent of cases did not have an apparent association with immunosuppression, 18% had a concurrent lymphoproliferative or autoimmune disorder and 9% developed PBL after solid organ transplantation. Oral involvement was observed in 21%, advanced stage in 60%, Epstein-Barr virus–encoded RNA expression was positive in 45% and Ki-67 expression of greater than or equal to 80% in 61% of the cases. Chemotherapy was documented in 43 patients, from which 43% received the cyclophosphamide, doxorubicin, vincristine, prednisone (CHOP)–like regimens. The median and the 2-year overall survival for the whole group were 9 months and 10%, respectively. Patients who had HIV-negative PBL have distinct clinicopathological characteristics, such as short overall survival and lower rates of oral involvement and Epstein-Barr virus–encoded RNA expression than the previously reported in HIV-positive patients.