Oral and Extraoral Plasmablastic Lymphoma: Similarities and Differences in Clinicopathologic CharacteristicsThe Authors’ Reply

Abstract

To the Editor We read with great interest the article by Hansra and colleagues1 in which they concluded that oral and extraoral plasmablastic lymphomas (PBLs) represent 2 distinct clinicopathologic entities. They found that oral PBLs commonly demonstrated monomorphic plasmablastic morphologic features without plasmacytic differentiation, whereas extraoral PBLs universally displayed plasmacytic differentiation. They also showed that patients with oral PBL had a higher incidence of Epstein-Barr virus (EBV) infection and better overall survival compared with patients with extraoral PBL. The article presents valuable information on the clinical, pathologic, and immunophenotypic features and outcome of oral and extraoral PBLs. In contrast with these results, we found some differences between their findings and those reported in the literature and our own experience.2–8 For example, their classifying PBLs based on anatomic locations may be problematic. Boy and coworkers2 evaluated 45 cases of oral PBL and found that all cases showed monomorphic, large blastic cells with some degree of plasmacytic differentiation. Colomo and colleagues3 found that anatomic locations of the tumors had little relation to morphologic characteristics: only 11 (48%) of 23 PBL cases of oral mucosa type (monomorphic, blastic appearance with no or minimal plasmacytic differentiation) occurred in the oral mucosa, with the remaining cases in extraoral sites. Likewise, in the same study, 2 of 16 cases of PBL with plasmacytic differentiation originated in oral mucosa. It has also been reported that PBLs with plasmacytic differentiation in the initial specimen transformed into monomorphic PBLs without plasmacytic differentiation in the recurrent tumor.4 These observations …