A Rare Cause of Obscure Gastrointestinal Bleeding

Excerpt

A 76-year-old male presented with persistent tarry stools and a significant drop in hemoglobin levels to 6.9 g/dL. Despite thorough examinations via upper endoscopy and colonoscopy, which yielded no notable findings, a subsequent abdominal computed tomography scan revealed focal thickening of the jejunum wall (Fig. 1, arrows). Consequently, a deep enteroscopy through an oral route was performed, uncovering an ulcerated mass in the deep jejunum. This mass was prone to contact bleeding and was associated with a small bowel loop connection (as shown in Fig. 2 and Supplementary Video 1). Due to ongoing bleeding, surgical consultation was sought, revealing the lesion 100 cm distal to the Treitz ligament, actively bleeding and accompanied by an entero-enteric fistula formation (Fig. 3).Histopathological analysis of the excised specimen revealed an aggregation of large, atypical lymphoid cells spanning the lamina propria, submucosa, muscularis propria, and serosa. Immunohistochemical studies confirmed the lymphoma cells to be CD20(+), CD3(−), CD10(−), Bcl-6(+), MUM-1(weakly positive at 35%), EBER(−), and Ki-67(80%). These findings led to the diagnosis of primary small intestinal diffuse large B-cell lymphoma.

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