Long-standing Sporadic Pancreatic Insulinoma: Report of a Rare Case

Abstract

Insulinomas are rare, functional pancreatic neuroendocrine tumors arising from the pancreatic multipotent stem cells or neuroendocrine islet, occurring with a higher proportion in females. Majority of insulinomas have a sporadic etiology; however, only 5%-10% develop as a part of multiple endocrine neoplasm type 1 syndrome. They usually present with symptoms of hypoglycemia including disturbance in orientation, tremors, diaphoresis, altered mental state, seizures and visual changes among others. The diagnosis is based on appreciation of the classic Whipple triad, i.e. neuroglycopenic symptoms and sympathetic drive along with low serum glucose levels (<50 mg/dL) and a complete reversibility of these symptoms with prompt administration of glucose. The gold standard treatment for insulinoma involves complete surgical excision (i.e. enucleation), which is curative in 90% of the patients. Health care physicians should have a high index of suspicion for this tumor in patients presenting with neurological and sympathetic symptoms, particularly if they are resolved after eating. Here, we report the case of a 48-year-old female with the history of multiple episodes of hypoglycemic symptoms for the past two years which improved on glucose intake. Furthermore, we also summarized the discussion regarding diagnosis and management of pancreatic insulinoma.