Disappearing Subepithelial Lesion

Abstract

Purpose: A 74 y/o veteran with ESRD on HD was found to have a 4.5 cm lesion in the gastric wall on a non contrast CT scan of abdomen done to evaluate a suprapubic catheter site for infection. The patient had no GI complaints. Subsequent EGD revealed a submucosal lesion in the proximal body of the stomach measuring approximately 4 cm. EUS was done and identified a 3.7 by 5 cm subepithelial complex lesion with anechoic components arising possibly from the 4th EUS layer; suspicious for GIST. FNA was not done due to coagulopathy. Repeat EGD with EUS was performed 10 days later for FNA; previously seen lesion could no longer be identified, by EUS or by direct visualization. Repeat CT with IV contrast confirmed absence of previously seen lesion but revealed evidence of necrotizing pancreatitis. Unfortunately, the patient decompensated further and expired. Discussion: Lesions, often referred to as submucosal, are fairly common findings on upper endoscopy and usually seen as a bulge, mass, or impression within gastric lumen that is covered by normal appearing epithelium. These lesions are more correctly termed subepithelial since they may arise from layers other then histological submucosa or may even be from extrinsic compression by a number of intra-abdominal structures, normal and abnormal. Approach and management of these lesions are in evolution and varies depending on availability of resources and technical expertise. Differential diagnosis for subepithelial lesion is broad and includes extrinsic compression due to pancreatic pseudocyst. It has been well known that pancreatic pseudocyst may regress or self-decompress on its own. There has been reported case of a pancreatic pseudocyst mimicking as a subepithelial lesion on endoscopy and CT scan, which regressed spontaneously with conservative management. Given the subsequent findings of necrotizing pancreatitis on CT with IV contrast and complete disappearance of the subepithelial lesion in this presented case the subepithelial lesion thought to be originating from one of the gastric layers was in actuality a pseudocyst, which then decompressed into the stomach lumen. Conclusion: Gastric subepithelial lesions are a common finding in endoscopy with a broad spectrum of differential diagnosis. Fortunately, with recent advances in imaging and EUS, these lesions are becoming easier to image and diagnose. However, clinicians should be aware of limitations of EUS. FNA in conjunction with EUS is crucial in initial assessment of these subepithelial lesions.