Current clinical and pathologic perspectives on gastric stromal tumors.

Gastric stromal tumors are heterogeneous and poorly understood. Investigators have studied these tumors by histologic and immunocytochemical characteristics, but interlaboratory variations have impeded clinical application of these techniques. Although many gastric stromal tumors can be categorized as benign or malignant with some certainty, occasional instances may present great difficulty in this distinction. Uncertainty about malignant potential and the biologic factors of the lesion will therefore generally suggest excision with a 1 to 2 centimeter margin for diagnosis and definitive therapy of these tumors. Subsequent prognosis will be dictated primarily by tumor size, histologic factors and mitotic index. Gastric stromal tumors in young women should suggest the possibility of Carney's triad. Functional extra-adrenal paragangliomas and pulmonary chondromas should be sought preoperatively. The paraganglioma should be managed first and the gastric lesion then addressed. Distal gastrectomy of at least 50 percent would seem to represent a reasonable resection limit. Identification of the specific cellular biologic factors of these lesions will be necessary to accurately classify particular tumors, gauge prognosis and individualize their management.