Hypoglycemia as the onset manifestation of somatostatinoma: A case report and review of the literature

Somatostatinoma is a rare pancreatic tumor characterized by diabetes mellitus, cholelithiases, and diarrhea. Although hypoglycemia is a distinctively unusual manifestation of the condition, most patients are symptomatic at the time of diagnosis. However, since the tumor is slow growing and symptoms are often not present for several years before diagnosis, the disease is often quite advanced by the time, patients seek medical attention and preoperative diagnosis is therefore often difficult. We reported a 30-year-old man who presented with hypoglycemia, hypersomnia and hyperinsulinemia. Magnetic resonance imaging (MRI) demonstrated a low-density mass in the head of the pancreas suggestive of a malignancy that was definitively identified as a somatostatinoma by immunohistochemical staining of a biopsy specimen.