Filling defects within the stomach can be divided into four basic categories including primary neoplasms, polyps, submucosal neoplasms, and granulomatous disease. Primary neoplasms of the stomach include carcinoma and lymphoma. Gastric carcinoma is the third most common gastrointestinal malignancy, most commonly adenocarcinoma. Predisposing factors include smoking, asbestosis, atrophic gastritis, pernicious anemia, H. pylori, gastrojejunostomy, and male gender (2:1). It can present as gastric ulcers, infiltrating superficial spreading masses, and polypoid masses. Any polyp greater than 2 cm in diameter must be considered malignant until proven otherwise. The cardia, antrum, and lesser curvature are most commonly involved. Lymphoma is rare (2% of all gastric malignancies), however the stomach is the most common location involved in the gastrointestinal tract. Lymphoma, usually non-hodgkins, can present as polypoid solitary masses, ulcerative masses, and diffuse infiltration.
Polyps occurring within the stomach include hyperplastic, adenomatous, and hamartomatous polyps. Hyperplastic polyps are most common (80%), usually small (<1 cm) and multiple. They predominantly affect the body and fundus and are associated with chronic gastritis. Adenomatous polyps (20%) are generally sessile, solitary, and most often present in the antrum. Associations include pernicious anemia, familial polyposis and Gardnerâ€™s syndrome. Malignant transformation is high. Hamartomatous polyps rare, have are very low malignant potential, and are most commonly seen in Peutz-Jeghers syndrome.
Submucosal neoplasms of the stomach include leiomyomas/sarcomas, lipomas, neurofibromas, and metastases. Leiomyomas/sarcomas arise from the smooth muscle of the stomach. In an upper GI series, leiomyomas most commonly appear as submucosal nodules. Ulceration is common, and can result in massive hematemesis. Neurofibromas also commonly appear as submucosal nodules, and are associated with neurofibromatosis type I. Metastatic disease can present as submucosal nodules and ulcerated masses. Melanoma, bronchus, breast, lung, lymphoma, Kaposiâ€™s, and adenocarcinoma commonly metastasize to the stomach.
Granulomatous causes of filling defects within the stomach include eosinophilic gastroenteritis, Chronâ€™s disease, tuberculosis, and sarcoidosis.
Mucosal edema surrounding peptic ulcers can have the appearance of a polyp with central collection of contrast material.
Finally, ectopic pancreatic tissue can occasionally present as gastric filling defects.