Duodenal Stromal Tumor with Neural Differentiation

A 49-year-old woman was admitted to our hospital for detailed evaluation of an abdominal mass. Ultrasonography and computed tomography revealed two tumors, one a submucosal lesion of the duodenal second portion and the other a left adrenal tumor. Angiography showed that the tumors were hypervascular. Both tumors were removed surgically and examined histologically using hematoxylin-eosin staining. The duodenal tumor (10 × 6 × 5 cm) was initially diagnosed as a schwannoma, but immunohistochemical studies showed that it was S-100 protein negative and neuron-specific enolase positive. Therefore, this tumor was identified as a stromal tumor with neural differentiation. The left adrenal tumor was a nonfunctioning adenoma. (Internal Medicine 32: 72-76, 1993)