LAUSR

Abstract Objective: An accurate diagnosis of a subepithelial tumor (SET) using endoscopic ultrasound (EUS) without tissue acquisition is difficult. Treatment plan for a SET may be influenced by endoscopic tissue diagnosis. We aimed to clarify the clinical outcomes of direct endoscopic biopsy for SET after removal of the overlying mucosa. Methods: We evaluated the medical records of 15 patients. All patients underwent direct endoscopic biopsy for a SET larger than 20 mm (involving proper muscle layer) after removal of the overlying mucosa. The rate of achieving an accurate diagnosis and the treatment decision after the procedure were evaluated. Results: The patients’ mean age was 55.1 ± 14.7 years. The patient population predominantly comprised men (9/15, 60%). The mean tumor size was 24.3 ± 7.8 mm. The mean biopsy number was 3.5 ± 1.7. No major complications occurred with the procedure. The mean procedure time was 15 ± 7.4 min. An accurate diagnosis was achieved in 93.3% of patients (14/15). The main pathological diagnoses after direct endoscopic SET biopsy were leiomyoma (33.3%, 5/15) and ectopic pancreas (33.3%, 5/15) followed by gastrointestinal stromal tumor (GIST) (13.3%, 2/15) and schwannoma (13.3%, 2/15). The treatment plan was influenced by the result of biopsy in 80% of patients (9/15), and unnecessary surgical resection was avoided. Conclusions: Direct endoscopic SET biopsy after removal of the overlying mucosa using an endoscopic conventional snare was a useful diagnostic tool with high diagnostic accuracy and low risk of complications.