Common Symptoms and a Rare Diagnosis: A Case of Duodenal Gastrointestinal Stromal Tumor Presenting as Gastrointestinal Bleeding.

Duodenal gastrointestinal stromal tumors (D-GISTs) are a rare subtype of GISTs, accounting for only 4% to 5% of all GIST cases. This case report details the presentation, diagnosis, and management of a 48-year-old female who presented with melena and anemia and was eventually diagnosed with a D-GIST. The tumor was identified through imaging studies, and histopathology performed after surgical resection revealed a submucosal neoplasm composed of spindle cells with extensive hemorrhage and necrosis. Given the tumor's rarity and its challenging presentation, which can mimic other conditions such as pancreatic masses, the case underscores the importance of considering D-GIST in differential diagnoses of duodenal or pancreatic lesions. Surgical resection remains the cornerstone of treatment, with adjuvant therapy considered in high-risk cases to prevent recurrence.