Insulinoma-a misleading neuroendocrine tumour

Abstract

Hypoglycemia is low blood sugar that could be caused by pancreatic tumors called insulinomas or islet cell tumors. The incidence is 1–4 per million1. While these tumors are usually benign, they produce large amounts of insulin, which lowers blood glucose levels. This is the opposite of the diabetes mellitus in which low insulin levels lead to hyperglycemia. Insulinomas present with the neuroglycopenic and sympathoadrenal symptoms induced by hypoglycemia2. Recurrent confusional states are typical of insulinoma. Other symptoms include visual changes, unusual behavior, palpitations, diaphoresis, and tremulousness3. Some cases with insulinoma present with neuropsychiatric symptoms and are often misdiagnosed as psychosis4. In one study, as many as 20% of patients had been misdiagnosed with a psychiatric, seizure, or other neurological disorder before the true diagnosis of insulinoma was made5. Because of its deceptive, disguising and nonpathognomonic symptomatology, insulinoma can pose a diagnostic dilemma even to a shrewd clinician and remain undiagnosed for years. The aim of reporting this case is to create clinical awareness among the healthcare professionals in order to avoid occurrence of a serious mistake in the diagnosis and treatment of insulinoma.