Gastrointestinal Autonomic Nerve Tumor: A Case Report with Electron Microscopic and Immunohistochemical Analysis and Review of the Literature

Abstract

A case of an adolescent girl with metastatic gastric stromal tumor is described. There were three metastatic nodules in the liver at the time of the admission. A subtotal gastrectomy was performed. The tumor had distinctly nodular appearance and was composed of a variety of cells suggestive of smooth muscle differentiation. Electron microscopy revealed cytoplasmic neural processes and densecore neurosecretory granules. Immunohistochemistry showed positive neuron-specific enolase, synaptophysin, and chromogranin A in some of the tumor cells. Similar findings in the primary tumor and its liver metastases indicated a primitive neural differentiation and enabled us to classify the lesion as a gastric autonomic nerve tumor. No other tumors that would suggest that the 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 months after the gastrectomy.