Patient with multifocal pancreatic insulinoma: a rare presentation of functional pancreatic neuroendocrine neoplasm

Abstract

Insulinoma is a type of neuroendocrine tumour with an incidence of 1—4 cases per million. Multiple insulinomas constitute less than 10% of all insulinomas. Surgery is the treatment of choice for insulinoma. The operation can be done with an open or laparoscopic approach, with cure rates ranging from 77% to 100%. Pancreatic resection is recommended for tumours larger than 2 cm in size, while enucleation is advised for lesions smaller than 2cm if the tumour is at least 2—3 mm away from the main pancreatic duct to prevent the formation of a fistula. For better intraoperative localization of lesions, bimanual palpation together with intraoperative ultrasonography (IOUS) is advised. Palpation alone has 70% sensitivity, but together with IOUS, it reaches 85—95%

A young female patient in her late 20s with non‑specific complaints and a medical history of epilepsy dating back to the age of 17 underwent a physical examination. Blood test results indicated severe hypoglycemia, and magnetic resonance imaging (MRI) revealed an 11‑mm neoplasia in the body of the pancreas. A 72‑hour fasting test confirmed the diagnosis of insulinoma, and the patient underwent laparoscopic surgery. IOUS was done for the precise localization of the lesion, and another tumour in the pancreatic tail was found. A spleen‑preserving laparoscopic distal pancreatectomy was performed. Histologic reports confirmed multifocal Grade 1 insulinoma. The postoperative course was uneventful. After 4 months of follow‑up, computed tomography (CT) was done, and there were no signs of recurrence of insulinoma, pancreatic pseudocysts, or other signs of postoperative complications. Since the operation, the patient has not had any episodes of hypoglycemia or seizures.

The wide spectrum of symptoms, which are not specific to insulinomas, in particular seizures, can make it difficult to establish a correct diagnosis and can be mistaken for other psychiatric or neurologic disorders. This case clearly shows the advantages of IOUS‑guided surgery in achieving better visualization and outcomes. After enucleation of the smaller lesion without the use of IOUS, other insulinomas would be missed and left in place because they were located deeply in the parenchyma. Simple visualization and palpation would not be enough.