Monomorphic epitheliotropic intestinal T-cell lymphoma may mimic intestinal inflammatory disorders

Abstract

There is a significant overlap between intestinal lymphoproliferative disorders (LPDs) and inflammatory conditions of the intestine, including inflammatory bowel disease (IBD), in clinical, endoscopic, or histologic appearance, leading to diagnostic challenges. We report two cases of monomorphic epitheliotropic intestinal T-cell lymphoma (MEITL) that were initially considered to be ulcerative colitis (UC) and lymphocytic colitis, respectively. Both patients presented with diarrhea and abdominal pain. Colonoscopy revealed hyperemia and scattered shallow ulcerations in the colon, without obvious mass. Microscopically, the first case exhibited features of active chronic colitis. The second case exhibited features mimicking lymphocytic colitis and ileitis. Correct diagnosis of lymphoma was established when the cases were received as consultation, with additional ancillary tests performed. Being familiar with the endoscopic features and unusual histologic patterns of MEITL described here is critical for prompt diagnosis and timely treatment, which may be conductive to a better prognosis.

Keywords: inflammatory bowel disease; lymphocytic colitis; microscopic colitis; monomorphic epitheliotropic intestinal T-cell lymphoma; ulcerative colitis.

Figure 1.

Colonoscopy with biopsies for case 1. (a) Ulcers in the descending colon. (b) Ulcers in the sigmoid. (c) Mild congestion and edema in the rectum. (d) In contrast to the relatively mild endoscopic findings of the rectum, histologically the infiltration is marked by dense atypical lymphoid cells with loss of crypts. (e) Low power view of the rectal lymphomatous infiltrate. (f) Higher power view of (e). Immunohistochemically the tumor cells are positive for (g) CD8, (h) CD56, (i) with high Ki-67 index.

Figure 2.

Esophagogastroduodenoscopy and biopsies of case 1. (a) Erosions in the gastric body. (b) Narrow band image of the gastric body. (c) Biopsy of the body mucosa showing marked atrophy. (d) High power view showing intraepithelial infiltrate by lymphomatous cells.

Figure 3.

Histologic findings in repeated biopsies of case 2. Infiltration by atypical lymphoid cells in (a) stomach, (b) duodenum, and (c) rectum. (d) Higher power view of (c), showing intraepithelial infiltration by monotonous medium-sized lymphoid cells with pale cytoplasm. (e) Immunostain for CK20 highlighting lymphoepithelial lesion. In addition, the tumor cells are strongly positive for (f) CD3, (g) CD8, and (h) CD56.