An Insulinoma Discovered in a Patient with Diffusely Calcified Chronic Pancreatitis.

Severe pancreatic calcification is a rare complication of neuroendocrine tumors (NET) (1, 2). We herein report the case of a 66-year-old man who suffered hypoglycemia following orthopedic surgery. A starvation test caused hypoglycemia (40 mg/dL) with a high serum level of insulin (18.2 μU/mL), satisfying Whipple’s triad. An abdominal CT scan showed diffuse pancreatic calcification (Picture A, B) with an early enhanced nodule in the uncus (Picture C), which was detected as a highly-intense region by diffusion MRI (Picture D). Arterial stimulation with venous sampling indicated that the gastro-duodenal artery was the main feeder. An endoscopic ultrasound (EUS)-guided pancreatic biopsy revealed an NET that immunostained with chromogranin A, synaptophysin and insulin. After a pancreatoduodenectomy with the removal of the stones, the blood glucose levels normalized without any medication. Pancreatolithiasis occurs in 22-60% of patients with chronic pancreatitis, while chronic pancreatitis can be a risk factor for sporadic NET (1). When the existence of an NET is suspected in patients showing pancreatic calcification, MRI, octreotide scintigraphy or EUS are recommended to detect a latent NET.