S836 Unmasking Esophageal Granular Cell Tumors: Clinical and Endoscopic Insights

Introduction: Esophageal granular cell tumors (EGCTs) are rare subepithelial neoplasms comprising less than 1% of all GCTs. Their variable presentations and histologic complexity pose diagnostic and management challenges. There are currently no established guidelines for the evaluation and treatment of EGCTs, leading to variability in clinical practice. This study aimed to describe the clinical features, diagnostic methods, and outcomes of patients with esophageal GCTs at a single center, with the goal of contributing to a more standardized approach to their management. Methods: We conducted a retrospective review of 19 patients diagnosed with esophageal GCTs from January 2010 to November 2024. Data collected included demographics, clinical presentation, tumor characteristics, endoscopic and histologic findings, treatment approach, and outcomes. Results: The mean age was 43 years, with a slight female predominance. Most lesions were incidentally found during evaluation for refractory gastroesophageal reflux disease (GERD) and were located in the lower esophagus. Endoscopic ultrasound (EUS) revealed hypoechoic submucosal nodules in 11 cases. Conventional endoscopic mucosal resection (EMR) was the most common treatment (68.4%), followed by EMR with hot snare and cap-assisted EMR. One case was managed conservatively. No complications, recurrences, or malignant transformations were observed. Immunohistochemistry was available for 11 cases, all positive for S-100, with CD68 and inhibin positive in 36%. Conclusion: EGCTs are rare, typically benign neoplasms increasingly detected due to widespread endoscopy use. Most are incidental findings, often located in the mid- to distal esophagus. Diagnosis relies on endoscopic appearance, EUS features, and confirmation via histology and immunohistochemistry (e.g., S-100 positivity). EMR is the preferred management for small, localized tumors, offering high rates of complete resection with minimal complications. In our series, all resected lesions were removed en bloc without recurrence. Cap-assisted and ligation-assisted EMR techniques were effective and safe. Notably, GERD symptoms were present in most patients, and a predominance of distal lesions raises the possibility of an association. Further studies are needed to clarify the clinical significance of this relationship and optimize management strategies.