Primary gastric Hodgkin's lymphoma expressing a B-Cell profile including Oct-2 and Bob-1 proteins.

Classic Hodgkin's lymphoma (cHL) most often involves lymph nodes, and gastric involvement is rare. Hodgkin's and Reed-Sternberg (H-RS) cells in cHL are known to often lack expression of several B-lineage markers, such as CD20, CD79a, Oct-2, and Bob-1. We present an extremely rare case of mixed-cellularity cHL in the stomach in which expression of these B-cells was detected immunohistochemically. The patient was an 83-year-old Japanese woman who developed a sensation of abdominal fullness and appetite loss. Endoscopic and abdominal computed tomography examinations revealed a gastric ulcer lesion and swelling of para-aortic lymph nodes, respectively. A subtotal gastrectomy was performed, and the histopathologic diagnosis was established as a typical cHL compatible with stomach origin. The patient underwent postoperative chemotherapy of 3 cycles of ABVD (doxorubicin, bleomycin, vinblastine, and dacarbazine) and has since been in complete remission. Immunohistochemically, the H-RS cells in the cHL were positive not only for CD30 but also for CD20, CD79a, Oct-2, and Bob-1, whereas they were negative for CD3, CD15, CD45, EMA, and ALK1. Our patient may have had an intermediate cHL disease overlapping that of non-Hodgkin's peripheral B-cell lymphoma, possibly reflecting derivation from germinal-center B-cells.