The Experience from Ten Insulinoma Cases

ABSTRACT

Introduction: Insulinoma is a rare, pancreatic functional neuroendocrine tumor, characterized by endogenous hyperinsulinemia, fasting hypoglycemia, and neuroglycopenic symptoms. It is diagnosed by a 72-h-fasting test, followed by localization studies. The common treatment option is the surgical excision. We hereby aim to discuss our clinical experience related to the patients of insulinoma.

Material and Method: A retrospective analysis was done on the history of the patients, who were hospitalized to our clinic due to hypoglycemia and biochemically detected insulinoma (glucose <55 mg/dL, whereas insulin > 3 μU/mL and C-peptide >0.6 ng/mL), between June 2007 and May 2015. Findings: The average age of the patients was 52,6 and ranged from 18 to 85 years. Five patients were men and five were women. All of the patients presented with fasting hypoglycemia. In one patient, the tumor was detected by DOTATATE scintigraphy. Seven patients underwent surgery and were cured. One patient demonstrated metastasis. The tumor could not be localized by ultrasound, CT, and MRI in two patients, and therefore, they were subjected to surgery after localizing the tumor by advanced imaging methods.

Discussion: In patients with fasting hypoglycemia and neuroglycopenia, along with Whipple’s triad, insulinoma should mainly be considered and a 72-h-fasting test should be conducted for diagnosis. The localization studies should be performed if the results are < 55 mg/dL for blood glucose, >3 μU/mL for insulin and > 0.6 ng/mL for C-peptide in blood sampled during the appearance of symptoms. We found that the triphasic thin slice CT, with multi-detector, was very useful for tumor localization in the test patients.