NK-cell enteropathy

NK-cell enteropathy (also known as lymphomatoid gastropathy or NK-cell enteropathy/lymphomatoid gastropathy) is an extremely rare, benign condition characterized by the infiltration of natural killer (NK) cells into the gastrointestinal tract, most commonly affecting the stomach, small intestine, and colon. Despite its alarming histological appearance, which can mimic aggressive NK/T-cell lymphoma, this condition follows an indolent clinical course and does not progress to malignancy in the vast majority of reported cases. Patients typically present with nonspecific gastrointestinal symptoms including abdominal pain, diarrhea, nausea, bloating, and gastrointestinal bleeding. Endoscopic findings may reveal mucosal erosions, ulcerations, or polyp-like lesions. Biopsy specimens show atypical NK-cell infiltrates in the lamina propria that are positive for CD56 and cytotoxic markers, and characteristically test positive for Epstein-Barr virus (EBV) encoding region (EBER) in some but not all cases. The cells typically lack T-cell receptor gene rearrangement, helping to distinguish this entity from true lymphoma. Because NK-cell enteropathy is a benign condition, aggressive chemotherapy is not warranted and should be avoided. Management is generally conservative and supportive, focusing on symptom relief. Some patients have been treated with corticosteroids or other immunosuppressive agents with variable results. The condition may persist or wax and wane over time, but long-term prognosis is generally favorable. Accurate diagnosis is critical to prevent unnecessary treatment with lymphoma-directed chemotherapy regimens, which would expose patients to significant toxicity without benefit.

Data sourced from FDA regulatory filings and ClinicalTrials.gov. Updated periodically.

Common questions about NK-cell enteropathy