Insulinoma: a rare neuroendocrine pancreatic tumor.

Insulinomas are functional endocrine tumors originating from the pancreatic b-cells. In 1902 Nicholls described the first adenoma of pancreatic islets, while the first insulinoma was described in 1927 in Mayo Clinic, which was dissected two years later in 1929 in Toronto. The first enucleation of insulinoma took place in a St. Jouis hospital in 1931, and after four years, in 1935, Whipple described the classic diagnostic triad: symptoms of fasting hypoglycemia or fatigue, blood glucose levels under 50 mg/dl and disappearance of symptoms after glucose administration.