Leiomyomas are a benign type of submucosal nodule usually found in the lower section of the esophagus. They can also occur in the stomach, rectum, or colon. Most leiomyomas cause no symptoms, but in some cases, they can cause dysphagia, or difficulty swallowing. Surgical removal of the leiomyoma may be recommended when dysphagia occurs, but when there are no symptoms, no treatment is required.
Granular Cell Tumors
Granular cell tumors are a type of submucosal nodule most commonly found in the esophagus, but they can also occur in the stomach, colon, rectum, and bile ducts. They are usually benign, but larger, faster-growing tumors can be cancerous. Removal of granular cell tumors is often recommended for both diagnosis and treatment.
Simple and Duplication Cysts
Simple cysts are fluid-filled sacs that can occur anywhere along the GI tract. Duplication cysts are rare congenital abnormalities. They can also occur anywhere along the GI tract, but they are least common in the stomach. Cysts are usually benign.
Occasionally, other organs, such as the liver, heart, gallbladder, or a blood vessel, protrude into the stomach, causing what looks like a submucosal nodule in some imaging tests. This is called extrinsic compression. Generally, an extrinsic compression cannot be identified without endoscopic ultrasound, or EUS.