CT of benign polypoid gastric masses: pearls, pitfalls & differential diagnosis

Any discrete protruding lesion in the stomach seen on endoscopy or imaging can be described as a 'polypoid' lesion. Polypoid lesions may represent simple benign gastric polyps that originate from the epithelium, or they may represent benign gastric masses including glomus tumor, lipoma, leiomyoma, schwannoma, gastric antral vascular ectasia (GAVE), and heterotopic pancreas. Glomus tumors are generally hypervascular solitary lesions found in the antrum. Lipomas are well-circumscribed, low-attenuation lesions composed of adipose tissue. Leiomyomas are well-circumscribed, hypodense lesions commonly found in the cardia. Schwannomas are rare, well-defined tumors that may show progressive enhancement. Heterotopic pancreas is a developmental anomaly that appears as a polypoid lesion, commonly in the antrum. GAVE appears as thickened antral folds that may mimic polypoid lesions. While benign epithelial polyps are the most common and are usually diagnosed and treated endoscopically, polypoid benign tumors are less common, often overlooked on imaging, and can mimic malignancy or be mistaken for simple polyps. This pictorial review highlights the characteristic CT appearances of these benign polypoid lesions, also shown in the visual abstract, and their differentiation from malignant mimics to help radiologists improve diagnosis and guide appropriate management.