Abstract
The patient was a 59-year-old woman in whom an asymptomatic pancreatic tumor was detected by ultrasonography. Dynamic CT revealed a hypervascular tumor in the body of the pancreas. We suspected it to be an islet cell tumor, but serum hormonal levels were within normal limits. The tumor was encapsulated and measured 1×1×1cm. It was extirpated in July, 1992, and histological examination revealed as islet cell tumor with evident trabecular and ribbon-like structures. No malignant cells were seen. Immunohistochemical studies showed that the tumor cells were positive for glucagon. Thus, it was diagnosed as an asymptomatic glucagon-producing tumor. No recurrence has been detected in the 6 years since the operation. We compared the clinical pathology of asymptomatic glucagon-producing tumors (group A) with symptomatic tumors (group S). The group A tumors were smaller and the patients had lower serum glucagon levels when compared with the group S. The group A also contained a higher proportion of benign tumors than the group S. We consider the prognosis of the former would be better than that of the latter.