Ventricular fibrillation resulting from electrolyte imbalance reveals vipoma in MEN1 syndrome.

Sporadic VIPoma is an exceedingly rare tumor with an annual incidence of 1:10 million people worldwide, yet it is described in approximately 5 % of MEN1 patients. The majority of VIPomas are malignant and radical surgery is the best therapeutic option. A 58-year-old man presented with cardiocirculatory arrest due to ventricular fibrillation. The patient had a 3-month history of epigastric pain with diarrhea. After reanimation, laboratory data revealed severe hypokalemia and hypercalcemia. Further investigations showed hyperparathyroidism, left adrenal adenoma and pituitary microprolactinoma and genetic diagnosis of MEN1 syndrome was made. Abdominal computed tomography revealed a 45 × 30 mm mass of the pancreatic head and two hepatic lesions, which proved to be neuroendocrine after 68 Ga PET and needle biopsy. Vasoactive intestinal peptide (VIP) serum level had increased. Subsequently the patient underwent pylorus-preserving pancreaticoduodenectomy and hepatic resection. Intraoperative VIP returned to normal values. Histopathology confirmed a pancreatic VIPoma metastatic to the liver. The postoperative course was unremarkable and the patient is well with no evidence of disease at a 48 months follow-up. Even in case of anusual presentation, when two or more main clinical findings of MEN1 related tumors are present, unrespectively to the presence of MEN1 mutation, MEN1 syndrome should be suspected. Surgery in MEN1 pancreatic neuroendocrine tumors is indicated both to treat symptoms and to avoid oncological progression even in advanced cases.