A malignant cause of hypoglycaemia: a metastatic insulin-secreting pancreatic neuroendocrine carcinoma.

Most cases of insulinomas are benign. We report a case of a malignant form of insulinoma. A 46-year-old man presented with behavioural changes associated with hypoglycaemia. Diagnostic work up revealed high serum insulin, high C-peptide and low glucose levels, compatible with endogenous hyperinsulinaemic hypoglycaemia. CT imaging of the abdomen revealed a pancreatic head mass and multiple liver masses. Biopsy of the pancreatic mass revealed a grade three pancreatic neuroendocrine carcinoma. Histological analysis of a liver mass showed that it was identical to the pancreatic mass, confirming its metastatic nature. The patient underwent distal pancreatectomy with en bloc splenectomy. There was persistence of hypoglycaemic symptoms after removal of the pancreatic mass, suggesting that the liver metastases were also functioning. Symptoms were controlled by diazoxide and octreotide long-acting release. The patient is already 1 year postsurgery with no recurrence of severe hypoglycaemia, and he has good functional capacity and has returned to his office job. 2016 BMJ Publishing Group Ltd.