Jejunal Gastrointestinal Stromal Tumor Presenting as Life-Threatening Melena and Profound Anemia: A Case Report.

Gastrointestinal stromal tumors (GISTs) are rare mesenchymal neoplasms and the most common sarcomas of the gastrointestinal tract. Small bowel GISTs, particularly jejunal tumors, frequently present with occult or overt bleeding leading to anemia, but are uncommon causes of melena when routine endoscopy has not been performed. We report a 67-year-old man who presented with one week of intermittent melena and profound anemia (hemoglobin 5.3 g/dL). Computed tomography (CT) angiography revealed a 5 cm jejunal mass without active bleeding. The patient underwent exploratory laparotomy with segmental resection and side-to-side anastomosis. Pathology confirmed a low-grade spindle cell GIST confined to the submucosa and muscularis propria, with strong diffuse CD117 and DOG1 positivity, scattered CD34 staining, and a Ki-67 index of ~3%. The patient recovered uneventfully with resolution of bleeding and normalization of hemoglobin. This case highlights the importance of considering small bowel GIST in unexplained melena and severe anemia and demonstrates the curative potential of timely surgical resection in localized low-risk disease.