Submucosal tumors of the stomach: a study of 100 operative cases

Mass screening for gastric cancer has been established in Japan, and asymptomatic submucosal tumors are often detected. This retrospective study was made to evaluate the proper surgical management of malignant submucosal tumors of the stomach.

One hundred submucosal tumors of the stomach were surgically resected, irrespective of symptoms and size. Up to 45% of these tumors, including 44 myogenic lesions, 23 non-Hodgkin's lymphomas, and 11 schwannomas, proved malignant. Myogenic sarcomas were classified in low and high grades according to mitotic rates, cellularity, and pleomorphism.

Thirty-five of 55 benign tumors and four of nine low-grade sarcomas underwent enucleation only, without recurrence. The remaining five low-grade and 11 high-grade sarcomas were treated by radical gastrectomy; the 5-year survival was 100% for the former and 80% for the latter. Eighteen patients with lymphomas underwent total or subtotal gastrectomy, and three patients underwent noncurative resection; the 5-year survival rates were 54.2% and 0%, respectively, with a clear significant difference (p < 0.001). Adjuvant chemotherapy was significantly superior to surgery alone (p < 0.05). Other factors did not affect survival of lymphoma.

With these observations, we believe that following the patients with submucosal tumor without surgery is not reasonable. Enucleation will suffice for low-grade sarcomas and benign tumors; high-grade sarcomas can be well treated by gastrectomy. Total or subtotal gastrectomy with systematic lymph node dissection when performed for cure can provide good results for resectable lymphomas.