Symptomatic hepatic metastasis of insulinoma 15 years after pancreatic resection

Abstract

Malignant insulinomas are infrequent endocrine tumors with miscellaneous clinical courses. In this report, wepresent a rare case of insulinoma that recurred with solitary hepatic metastasis 15 years after the initial resection ofthe primary tumor from the pancreas. A 20-year-old woman first presented with the symptoms of hypoglycemia in1996. The diagnosis of pancreatic insulinoma was confirmed by laboratory findings, and the initial surgery had beenperformed involving complete enucleation of the pancreatic mass. Histopathologically, the tumor was diagnosed asa benign adenoma. After 15 years, the patient experienced symptoms of hypoglycemia again, and laboratory findings and abdominal computed tomography identified a lesion in the liver. Intraoperative ultrasound did not showany lesion in the pancreas, and wedge resection was performed for the hepatic lesion. Postoperative blood glucoselevels returned to normal. Histopathologic examination confirmed the diagnosis of liver metastasis of a neuroendocrine tumor. This is the longest interval between primary tumor and the metastasis reported in the literature, forinsulinoma. Thus, it should be remembered that long-term follow-up is mandatory for the patients with insulinomaeven after resection of the primary tumor. Resection is recommended when a metastatic lesion is observed.