Natural killer (NK) cell enteropathy is not well understood. Although NK-cell enteropathy is typically benign, aggressive NK-cell lymphoma is an important differential diagnosis. This paper reports a rare case of NK-cell enteropathy of the stomach presenting with dyspepsia and weight loss. In this case, upper endoscopy revealed an ulcer-like lesion (approximately 7 mm) surrounded by erythema, edema, and mucosal hemorrhage. The biopsy revealed atypical lymphocyte cells expressing CD56 without an Epstein-Barr virus infection, which is consistent with NK-cell enteropathy. Follow-up endoscopy 2 months later revealed lesion regression with mild erythema. The patient was observed closely for 6 months, with no evidence of lymphoma.
Keywords: Intestinal diseases; Killer cells, natural; Lymphoma; Stomach.