Authors: Hui Yuan , Tingyv Huang , Lijuan Kang , Xue Li

Abstract

Background: Monomorphic epitheliotropic intestinal T-cell lymphoma (MEITL) is a rare, highly aggressive primary intestinal T-cell lymphoma predominantly observed in male populations in Asia and Latin America. The disease most commonly involves the proximal small intestine, particularly the jejunum, and is characterized by non-specific clinical manifestations. 

Case Presentation: We report the case of a 37-year-old male who presented with periumbilical abdominal pain of indeterminate etiology, which subsequently migrated to the left upper quadrant. Computed tomography (CT) of the abdomen revealed focal wall thickening in the small intestine within the right lower quadrant and left middle-upper abdomen, alongside marked irregular thickening and rigidity in the left upper abdomen, findings suggestive of a neoplastic lesion. Intraoperatively, a firm mass measuring approximately 8 cm × 10 cm was identified in the small intestine. Histopathological examination confirmed the diagnosis of MEITL; notably, the tumor cells exhibited expression of the B-cell immunohistochemical marker CD20.

Conclusion: MEITL is characterized by a low incidence and poses significant challenges for early detection. T-cell lymphomas co-expressing CD20 are rare, and the prognostic implications of CD20 expression in MEITL remain controversial. Further studies with larger sample sizes are warranted to elucidate this relationship, with the goal of facilitating more precise treatment strategies and improving patient outcomes.

Keywords: Intestinal T-cell lymphoma, monomorphic epitheliotropic intestinal T-cell lymphoma, immunohistochemistry, prognosis.