Korean J Gastroenterol.  2021 Dec;78(6):349-352. 10.4166/kjg.2021.116.

Natural Killer-cell Enteropathy of the Stomach in an Elderly Woman: A Case Report

• Koo Yy
• Lee J
• Kim B
• Jeong SJ
• Oh EH
• Park YE
• Park J
• Kim TO

• KMID: 2523597
• DOI: http://doi.org/10.4166/kjg.2021.116

Abstract

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.

Keyword

Killer cells; natural; Intestinal diseases; Lymphoma; Stomach

Figure

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  Fig. 1 Initial endoscopic images. (A, B) Esophagogastroduodenoscopy shows an 8-mm, reddish ulcer-like lesion surrounded by erythema, edema, and mild mucosal hemorrhage on the gastric fundus.

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  Fig. 2 Histopathological findings. (A) In low-power magnification, medium-sized lymphocytes proliferated in lamina propria (hematoxylin and eosin stain [H&E], ×50). (B) Lymphoid cells showed clear cytoplasm and slightly enlarged nuclei. Lymphoepithelial lesions were noted (black arrow). (H&E, ×200). (C) CD56 immunohistochemical staining was positive (CD56 stain, ×200). (D) EBER in situ hybridization was negative (EBV ISH, ×200).

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  Fig. 3 Follow-up endoscopic images. (A) Two months later, repeated endoscopy shows regression of lesion with mild erythema. (B) Narrow-band image with magnification.

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