A Rare Case of Gastrointestinal Stromal Tumor Outside the Gastrointestinal Tract

Extra-gastrointestinal stromal tumors are rare mesenchymal tumors occurring outside the gastrointestinal tract, comprising ~5% of all gastrointestinal stromal tumors. A 65-year-old man undergoing evaluation for nephrolithiasis was incidentally found to have a 7.2 cm mesenteric mass proven to be gastrointestinal stromal tumors on biopsy. After limited response to imatinib, the patient underwent successful surgical resection. Mesenteric gastrointestinal stromal tumors often present larger and more aggressive, but in this instance, early incidental detection permitted effective intervention. This case highlights the diagnostic challenges posed by extra-gastrointestinal stromal tumors due to their atypical location and nonspecific symptoms. Extra-gastrointestinal stromal tumors should be considered in the differential diagnosis of abdominal masses outside the gastrointestinal tract and require high clinical suspicion for diagnosis. Immunohistochemistry and molecular testing are critical for accurate identification and treatment. Early detection and multidisciplinary management are key to favorable outcomes.