Leiomyosarcomas of the gastrointestinal tract are smooth-muscle tumors that arise in the muscularis propria [1]. The tumors are uncommon, accounting for 1% of gastric, 20% of small-bowel, and 0.1% of colorectal tumors [2]. Most gastrointestinal leiomyosarcomas occur in the stomach [1]. These tumors are most frequently seen in adults (median age, 56 years), with more men than women being affected (male-female ratio, 2:1).
The average duration of symptoms at presentation is 4-6 months; symptoms include nausea and vomiting, pain, weight loss, bleeding, or a palpable mass [1]. Endoscopy is often performed for assessment, but because the lesions are submucosal and usually extraluminal, a biopsy specimen with positive findings may not be obtained [1]. CT is useful in the detection and characterization of the mass and in the evaluation of possible spread. The purpose of this pictorial essay is to review the CT findings of the primary tumor and metastatic lesions of gastric leiomyosarcoma and to highlight CT features that are most helpful for diagnosis.