Localization of small sized insulinoma by means of combining arteriography with CT: a case report and review of the literature.

Background: The majority of pancreatic insulinomas are of small size and conventional imaging examinations such as percutaneous ultrasonography (US), Computerized Tomography (CT) and MRI usually fail to reveal the lesion. In this article we describe the potential role of combining arteriography with CT, which is superior to single arteriography or CT.

Methodology: A 45-year-old man who suffered from significant catecholaminergic and neuroglycopenic symptoms, such as hypodynamia, sweating, impaired memory and confusion, was diagnosed with insulinoma by biochemical tests. The serum level of glucose of fast in the morning was as low as 1.2 mmol/L, coincident with the low serum level of glucose; the serum level of insulin was 28.77 mIU/L. The fasting insulin-to-glucose ratio was higher than 0.4. The C-peptide of 1097.62 pmol/L was higher than normal. The lesion was not identified on US, CT scan or arteriography. However the combination of arteriography with CT revealed the small insulinoma located at junction of the body and the tail of the pancreas, about 1.0 x 0.8 cm.

Results: Intraoperative ultrasound (IOUS) verified the lesion which located in the posterior and superior aspect of the pancreas and spleen-preserving distal pancreatectomy was performed. Histopathology confirmed the diagnosis. After the surgery the patient underwent a good recovery and was discharged two weeks later. He has developed no further episodes of hypoglycemia two years after the surgery.

Conclusion: Combining arteriography with CT is a valuable examination for insulinoma, and IOUS is helpful to verify the lesion. Entire excision of the lesion is the best way of treatment.