Malignant insulinoma presenting a non-functioning metastatic liver tumor 14 years after resection of the primary tumor.

A 58-year-old woman who had undergone resection of insulinoma 14 year earlier visited our clinic complaining of abdominal discomfort. Computerized tomographic scan showed multiple liver tumors, and a diagnosis of metastatic tumor of malignant islet cell tumor was confirmed histologically. No oversecretion of hormones or hypoglycemic episode was observed on readmission. Thus, the insulinoma seemed to have transformed to a clinically non-functioning tumor. The patient was treated with transcatheter arterial embolization, resulting in clinical improvement with marked reduction in tumor size. Features of interest in this case included; (1) transformation to non-functioning metastatic liver tumor 14 years after resection of insulinoma, (2) the usefulness of transcatheter arterial embolization for multiple metastatic tumor of malignant islet cell tumor.