Objective: Submucosal tumors (SMTs) are occasionally found in the esophagus during upper endoscopy. Granular cell tumors (GCTs) are reported to be the second most common esophageal mesenchymal tumors, after leiomyomas. Endoscopic ultrasonography (EUS) is an effective tool for predicting the histologic characteristics of SMTs by providing an accurate image of the layering structure of the esophagus, but it is hard to differentiate GCTs from submucosal leiomyomas accurately with conventional EUS. The aim of the present study was to characterize the EUS features of GCTs compared with those of submucosal leiomyomas using a high-frequency catheter probe EUS.
Material and methods: A total of 41 patients with GCTs or submucosal leiomyomas were included. All of the patients underwent EUS before histologic confirmation by endoscopic resection or biopsy.
Results: There were 14 GCTs in 12 patients and 30 leiomyomas in 29 patients. GCTs had a white-to-yellow surface color more frequently than leiomyomas. In comparison with the surrounding normal proper muscle layer, the echogenicity of the leiomyomas was similar to that of the surrounding muscle layer, but more than half of the GCTs were hyperechoic compared to the surrounding muscle layer. Unclear borders were observed more frequently in GCTs than in leiomyomas. The presence of at least two of these three features in a given tumor had a sensitivity of 85.7%, a specificity of 96.7%, and an accuracy of 93.2% for predicting GCTs.
Conclusions: High-frequency probe EUS is helpful for differentiating esophageal GCTs from submucosal leiomyomas.