Case of plasmablastic lymphoma of the sigmoid colon and literature review

Figure 1 Computed tomography of abdomen. Computed tomography scan showed a mass measuring 5 cm in diameter, multiple diverticula in the sigmoid colon and enlarged lymph nodes in the sigmoid mesentery.

Figure 2 Gross appearance of the primary tumor lesion. A: A tumor (5 cm in diameter) is present in the sigmoid colon. Coagulation is on the surface; B: The tumor showed hemorrhage on the surface and a white mass within and was soft in consistency.

Figure 3 Plasmablastic lymphoma of the sigmoid colon. A: Tumor cells have large hyperchromatic nuclei with prominent nucleoli. Some tumor cells showed plasmacytic differentiation [hematoxylin and eosin (HE) staining, original magnification × 400]; B: The atypical cells are negative for the B-cell marker CD20 (original magnification × 400); C: The atypical cells are diffusely positive for the plasma cell marker CD138 (original magnification × 400); D: The nuclei of the atypical cells are positive for EBER, which is Epstein-Barr encoded RNA (original magnification × 400); E: The atypical cells are negative for the leukocyte common antigen CD45RO (UCHL1) (original magnification × 400); F: The atypical cells are negative for the T-cell marker CD3 (original magnification × 400); G: The atypical cells are negative for the pan-B-cell marker CD79a (original magnification × 400).