Gastric schwannomas revisited: has precise preoperative diagnosis become feasible?

BACKGROUND: Gastric schwannomas are not common but are clinically important in terms of differential diagnosis from other submucosal lesions. The precise preoperative diagnosis, however, has been challenging mainly owing to the lack of specific findings in conventional imaging studies. The aim of this study was to revisit the possibilities and limitations of modern preoperative diagnostic modalities for gastric schwannomas.
METHODS: Fourteen consecutive patients with a final pathological diagnosis of gastric schwannoma were retrospectively analyzed. Data included demographics, preoperative imaging studies/diagnosis, surgery, histopathology, and follow-up results.
RESULTS: The series included 6 males and 8 females, with a median age of 49 years (range 26-68 years). No symptoms were presented, except for 1 patient with epigastric pain. The tumors were located in the upper (n = 5), middle (3), and lower stomach (6), with a median size of 41 mm (range 20-75 mm). Twelve schwannomas (86%) showed homogeneous enhancement on computed tomography. Ulceration was seen on endoscopy in 4 of 12 available cases (33%). Positron emission tomography was performed in the last 4 patients, showing fluorodeoxy-glucose uptake in all cases (100%). A preoperative diagnosis of schwannoma was not obtained in the majority of cases (13/14, 93%); only 1 case was correctly diagnosed, by endoscopic aspiration cytology. Laparoscopic partial gastrectomy was attempted and completed in 13 cases. The patients have been followed up for 4.7 years (range 2.1-20.3 years), with no recurrencesor metastases and acceptable gastrointestinal function.
CONCLUSIONS: The precise preoperative diagnosis of gastric schwannomas remains difficult even with modern imaging studies. Surgery, therefore, should be positively considered for patients without a conclusive preoperative diagnosis.