Gastric calcifying fibrous tumor removed by endoscopic submucosal dissection

The World Health Organization describes calcifying fibrous tumors (CFTs) as rare, benign lesions characterized by hypocellular, densely hyalinized collagenization with lymphoplasmacytic infiltration. These tumors rarely involve the gastrointestinal (GI) tract. A routine endoscopic upper gastrointestinal screen detected a 10-mm submucosal tumor (SMT) in the lesser curvature of the lower corpus of the stomach of an apparently healthy, 37-year-old woman with no history of Helicobacter pylori infection. Endoscopic ultrasonography (EUS) localized the internally isoechoic, homogeneous SMT mainly within the submucosa. Malignancy was ruled out using endoscopic submucosal dissection (ESD). A pathological examination confirmed complete resection of the SMT, and defined a hypocellular, spindle-cell tumor with a densely hyalinized, collagenous matrix, scattered lymphoplasmacytic aggregates as well as a few psammomatous, dystrophic calcified foci. The mass was immunohistochemically positive for vimentin and negative for CD117 (c-kit protein), CD34, desmin, smooth muscle actin (SMA) and S100. Therefore, the histological findings were characteristic of a CFT. To date, CFT resection by ESD has not been described. This is the first case report of a gastric calcifying fibrous tumor being completely resected by ESD after endoscopic ultrasonography.