Primary Natural Killer-Cell Lymphoma of the Gastrointestinal Tract

Figure 1 A 70-year-old woman was admitted with lower abdominal pain. An 8-cm mass was palpable in the left lower quadrant of the abdomen. Abdominopelvic computed tomography showed irregular thickening of the small bowel on the left side of the abdominal cavity.

Figure 2 Esophagogastroduodenoscopy demonstrated an ulcerated, infiltrating lesion which occupied 50 % of the lumen in the third part of the duodenum.

Figure 3 Histological examination of the duodenal biopsy revealed a true natural killer-cell lymphoma, with transmural infiltration of large pleomorphic cells. These cells were CD56-positive (Anti-CD56; Santa Cruz Biotechnology Inc., Santa Cruz, California, USA; × 400), but did not express surface CD3 or T-cell lineage.

Figure 4 An ulcerated and excavated mass in a portion of resected jejunum showing multifocal hemorrhage and necrosis. Histologically, this was also revealed to be a true natural killer-cell lymphoma.