Gastric Schwannoma: A Case Report of a Rare Differential Diagnosis to Consider in Gastric Tumours

Schwannomas are rare mesenchymal spindle cell tumors arising from Schwann cells. They account for approximately 0.2% of all gastric tumors and originate from the Auerbach and Meissner plexuses. We report the case of a 61- year- old man with a 5- cm exophytic lesion located in the gastric antrum, incidentally detected on routine imaging, which prompted upper gastrointestinal endoscopy. Endoscopic evaluation revealed a subepithelial tumor without mucosal ulceration. Further assessment with endoscopic ultrasound confirmed that the lesion originated from the muscularis propria. A biopsy was performed, establishing the diagnosis of schwannoma based on histological and immunohistochemical findings. Following discussion at a multidisciplinary meeting, surgical management was recommended. The patient underwent laparoscopic subtotal gastrectomy with Billroth II reconstruction. Gastric lesions encompass a broad spectrum of differential diagnoses with variable prognoses. Although rare, gastric schwannomas should be considered by both surgeons and pathologists. As these tumors are predominantly benign, the principal challenge lies in achieving an accurate diagnosis before initiating treatments aimed at alternative differential diagnoses.