Abstract
We report a case of an insulinoma of which localization was identified by selective arterial stimulation and venous sampling (ASVS) as well as pre- and intra-operative imaging diagnoses, with resultant surgical resection. The patient was a 67-year-old woman. She was brought into the hospital because of unconsciousness by ambulance, when the blood glucose concentration was low, 36mg/dl. Rapid intravenous injection of glucose yielded prompt improvement of unconsciousness. Dynamic CT scan, magnetic resonance imaging scan, and abdominal angiography showed a tumor 1.5cm in diameter at the uncus of the pancreas. ASVS disclosed a remarkable increase in blood immunoreactive insulin (IRI) in the superior mesenteric artery. We identified the tumor by intraoperative ultrasonography and palpation, and then enucleated the tumor. Further we measured peripheral blood sugar concentration, IRI, portal IRI before and after the enucleation, and confirmed that the tumor was completely removed. No symptoms such as hypoglycemic episodes were seen after the operation.
Since insulinomas are benign and are expected to have favorable prognosis by surgical resection in most cases, the treatment of choice for them is surgical resection while the pancreatic function is preserved as possible as we can. For that, correct diagnosis of the localization of the tumor and intraoperative confirmation of complete removal are important, and from this standpoint, further accumulation of clinical cases is expected.
