GASTROINTESTINAL AUTONOMIC NERVE TUMOR - A CASE-REPORT WITH ELECTRON-MICROSCOPIC AND IMMUNOHISTOCHEMICAL ANALYSIS AND REVIEW OF THE LITERATURE

A case of an adolescent girl with metastatic gastric stromal tumor is described. There were three metastatic nodules in the liver at the tim e of the admission. A subtotal gastrectomy was performed. The tumor ha d distinctly nodular appearance and was composed of a variety of cells suggestive of smooth muscle differentiation. Electron microscopy reve aled cytoplasmic neural processes and dens-core neurosecretory granule s. Immunohistochemistry showed positive neuron-specific enolase, synap tophysin, and chromagranin A in some of the tumor cells. Similar findi ngs in the primary tumor and its liver metastases indicated a primitiv e neural differentiation and enabled us to classify the lesion as a ga stric autonomic nerve tumor. No other tumors that would suggest that t he gastric lesion is a part of Carney's triad were detected. The child was treated with chemotherapy but the liver metastases did not change significantly. She is alive with unresectable liver metastases 10 mon ths after the gastrectomy.