Monomorphic Epitheliotropic Intestinal T-cell Lymphoma Presenting With Significant Villous Atrophy in the Small Intestine.

Monomorphic epitheliotropic intestinal T-cell lymphoma (MEITL) is a rare and aggressive primary intestinal T-cell lymphoma with a high mortality rate and poor prognosis. Although endoscopy plays a key role in early diagnosis, reports on detailed endoscopic findings are limited. Here, we present a case of MEITL with refractory diarrhea and significant villous atrophy, as observed on endoscopy. A 67-year-old woman was admitted to our hospital with refractory diarrhea and weight loss. Esophagogastroduodenoscopy revealed microgranular mucosa with significant villous atrophy in the duodenum. Enhanced magnifying endoscopy with narrow band imaging showed flattening and loss pattern of the villi in the transverse part of the duodenum. Colonoscopy also showed significant villous atrophy in the ileum. Biopsy specimens from the duodenum and ileum showed diffuse proliferation of small- to medium-sized atypical lymphoid cells in the lamina propria and intraepithelial lymphocytes. Immunohistochemistry revealed that the cells were positive for CD3, CD8, CD56, and Granzyme B. Diagnosing MEITL, PVPP (sobuzoxane, etoposide, and prednisone) chemotherapy was administered. However, since the patient developed intestinal obstruction after two courses of chemotherapy, it was discontinued. The patient died of intestinal perforation 82 days after diagnosis. MEITL can cause villous atrophy in the small intestine. Hence, magnifying endoscopy and follow-up histological examination are essential when villous atrophy is observed in patients with refractory diarrhea.