A RARE CASE OF CD8-NEGATIVE MONOMORPHIC EPITHELIOTROPIC INTESTINAL T-CELL LYMPHOMA

Monomorphic epitheliotropic intestinal T-cell lymphoma (MEITL) is an uncommon subtype of intestinal lymphoma that is usually found in Asian populations. MEITL causes non-specific gastrointestinal-related symptoms; thus, it is often overlooked and misdiagnosed, resulting in complications and improper therapeutic approaches. A 75-yearold Asian female was admitted to the emergency room with signs and symptoms of ileal obstruction. She had no history of celiac disease. Surgical resection was performed; the tumor consisted of small- to medium-sized tumor cells arranged in a monomorphic and diffuse pattern. The tumor was positive for CD3 and CD56 but negative for CD8. She was diagnosed with MEITL. Although most MEITL tumors are positive for CD3, CD56, and CD8, CD8-negative MEITL has been reported in some studies and is thought to originate from double-negative intraepithelial lymphocytes. We described a rare case of MEITL with an unusual negative CD8 expression.