Pancreatic insulinoma: Diagnosis and treatment of a rare tumour with misleading symptoms — A case report

INTRODUCTION: Insulinomas are an uncommon occurrence, with an annual incidence of approximately 4 per million. These functional pancreatic neuroendocrine tumours can present with a myriad of nonspecific symptoms leading to frequent misdiagnoses. PRESENTATION OF CASE: In this case report is presented a 55-year-old man who was misdiagnosed and managed for a seizure disorder with escalating antiepileptic treatments for 11 months. A thorough history after an attack was the main tool in solving the mystery of his refractory seizures, leading to the discovery of a pancreatic insulinoma. Biochemical tests revealed fasting hypoglycaemia and a relative hyperinsulinemia, and a distal pancreatic lesion measuring approximately 1.8 cm × 1.3 cm was detected on CT, MRI and endoscopic ultrasound. Successful laparoscopic pancreatic left resection led to complete resolution of symptoms and restoration of quality of life to pre-illness levels. DISCUSSION AND CONCLUSION: Insulinomas have historically been difficult to diagnose because their symptoms mimic neurologic and psychiatric conditions. Patterns of symptom occurrence obtained from a carefully-taken history is the single most important tool in assessing patients with insulinomas, who usually present with unusual and refractory neuropsychiatric conditions.