Epstein–Barr virus-positive ileal extraosseous plasmacytoma containing plasmablastic lymphoma components with CD20-positive lymph node involvement

Makoto Saito,¹ Masanobu Morioka,¹ Ko Izumiyama,¹ Akio Mori,¹ Tatsuro Irie,¹ Masanori Tanaka,¹ Yoshihiro Matsuno<sup>2

1</sup>Department of Internal Medicine and Hematology, Aiiku Hospital, Sapporo, Japan; ²Department of Surgical Pathology, Hokkaido University Hospital, Sapporo, Japan

Abstract: We report a case of Epstein–Barr virus (EBV)-positive ileal extraosseous plasmacytoma containing plasmablastic lymphoma components with CD20-positive lymph node involvement. A 34-year-old healthy Japanese male developed intussusception due to an ileal plasmacytoma. The lesion was positive for EBV-encoded small nuclear RNA in in situ hybridization, with the surrounding lymph nodes showing the expression of CD20. Tumor cells in the ileal and lymph node lesions contained high-grade malignant features compatible with plasmablastic lymphoma. Because his abdominal lymph nodes recurred 6 months after resection, he received six cycles of R-CHOP chemotherapy (rituximab, cyclophosphamide, doxorubicin, vincristine, and prednisolone), and had a complete remission. Although his case was complicated by acute promyelocytic leukemia, he has so far survived, recurrence-free, for more than 7.5 years after chemotherapy for extraosseous plasmacytoma.

Keywords: ileal extraosseous plasmacytoma, plasmablastic lymphoma, Epstein–Barr virus (EBV), lymph node involvement, CD20, R-CHOP