Giant jejunal gastrointestinal stromal tumor presenting as refractory anemia: a case report of complex R0 resection.

Introduction and importance: Gastrointestinal stromal tumors (GISTs) are the most common mesenchymal tumors of the digestive tract. Small-bowel GISTs account for 20-30% of cases and often present late because of exophytic growth and nonspecific symptoms. Chronic mucosal ulceration may result in iron-deficiency anemia. Presentation of the case: A 51-year-old man with type 2 diabetes mellitus, bronchial asthma, obesity, hypertension, and chronic ischemic heart disease presented with 4 months of melena, abdominal discomfort, weakness, and dizziness. His hemoglobin decreased to 60 g/L before referral, requiring transfusion of three units of packed red blood cells. On admission, hemoglobin was 86 g/L with microcytosis and thrombocytosis. Contrast-enhanced computed tomography revealed a 14 × 9 × 8 cm exophytic jejunal mass with heterogeneous enhancement, central low-density change, and involvement of adjacent bowel loops. Differential diagnoses included GIST, adenocarcinoma, lymphoma, neuroendocrine tumor, leiomyosarcoma, desmoid-type fibromatosis, and metastatic disease. Open en bloc resection of the involved bowel segments with two side-to-side anastomoses achieved R0 resection without tumor rupture. Clinical discussion: Histopathology demonstrated spindle-cell GIST with 4-6 mitoses per 50 high-power fields, diffuse CD117 and DOG1 positivity, and a Ki-67 index of 10%. Based on its size, jejunal location, and mitotic activity, the tumor was classified as high-risk according to the AFIP/Miettinen criteria. The postoperative course was stable. Long-term follow-up data were unavailable. Conclusion: A giant jejunal GIST should be considered in patients with unexplained gastrointestinal bleeding and severe anemia. Early imaging, surgical planning, avoidance of tumor rupture, standardized risk assessment, and oncologic management are essential.