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

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: CD20; Epstein-Barr virus (EBV); R-CHOP; ileal extraosseous plasmacytoma; lymph node involvement; plasmablastic lymphoma.

Figure 1

Gross findings of the primary lesion. A 6.5 cm × 4.0 cm tumor (A) was observed in the terminal ileum (arrows). The tumor was elevating and had a subpedunculated feature (B).

Figure 2

Histopathological findings. In the primary lesion (A), the tumor showed consistent with plasmacytoma. In some areas of the primary lesion (B), plasmablastic lymphoma-like features were observed. In the regional lymph nodes (C), involvement by plasmacytoma cells was observed (D). EBER in situ hybridization showed the tumor cells were positive. MIB-1 (Ki-67) labeling index of the tumor cells (E) was approximately 80%–90%. Primary lesion (F) was negative. Lymph node lesion (G) was positive. Notes: Original magnification of (A–G): ×400. (A–C) resulted from HE staining, (F and G) from CD20 immunostaining. Abbreviations: EBER, Epstein-Barr virus-encoded small nuclear RNA; HE, hematoxylin and eosin.

Figure 3

Abdominal computed-tomography findings. (A) The abdominal lymph nodes (indicated by arrow) were observed. (B) The lymph nodes disappeared after R-CHOP chemotherapy. Abbreviation: R-CHOP, rituximab, cyclophosphamide, doxorubicin, vincristine, and prednisolone.