Multifocal gastrointestinal stromal tumor (GIST) of the stomach in an 11-year-old girl.

A previously healthy 11-year-old girl presented with an 8-month history of anemia and left upper quadrant abdominal pain. US examination demonstrated a 9-cm cystic mass with a fluid-fluid level in the left upper quadrant with unclear organ of origin. Abdominal MR imaging demonstrated a complex cystic mass, likely arising from the stomach. Additional T2 hyperintense submucosal lesions were identified in the gastric wall. Surgical excision confirmed the diagnosis of multifocal gastric gastrointestinal stromal tumor (GIST). MR imaging was helpful in suggesting a gastric origin of the primary mass and in demonstrating multifocal disease within the stomach.