Primary Gastric Leiomyosarcoma Presenting as an Endoscopic Diagnostic Pitfall: A Case Report.

Leiomyosarcomas are malignant tumors derived from cells that exhibit smooth muscle differentiation. Although primary leiomyosarcoma of the stomach has occasionally been reported in the form of case reports, its publication in radiology journals is exceedingly rare; therefore, preoperative diagnosis remains challenging. Herein, we report the imaging and endoscopic findings of a 71-year-old woman with primary gastric leiomyosarcoma that was initially misdiagnosed as early gastric cancer on endoscopy and as a small subepithelial tumor on CT.