A rare case of insulinoma presented with neurological manifestations: A case report

Insulinoma is a rare, most commonly benign tumor with several manifestations that may be misattributed to psychiatric, cardiac, or neurological disorders.

In this report, we describe the case of a 47-year-old woman who presented with neurological manifestations, including seizures, that were misdiagnosed initially as seizures due to small vessel ischemic disease and managed accordingly with various antiepileptic drugs without any benefit. An endocrinologist's assessment suggested measuring the levels of glucose, insulin, and C-peptide. The results were abnormal. Subsequently, an enhanced-contract CT scan followed by an MRI of the abdomen was requested, and it revealed a well-delineated lesion measuring about (3,2 × 2,1 × 2,2) cm located in the tail of the pancreas. On laparoscopic visualization, a partial pancreatectomy was accomplished using a stapler. Histopathology of the surgical specimen revealed a benign insulinoma with free margins. The follow-up after three months demonstrated that the patient was doing well.

Although insulinoma is mostly benign, conservative surgery such as enucleation or partial pancreatectomy is usually the cornerstone of treatment. If other indicators such as large size, multiplicity, proximity to the major pancreatic duct, association with MEN1, and malignancy were present, radical resection was considered.

A high index of suspicion is requested to establish the diagnosis of insulinoma, especially when presenting with severe neurological symptoms like seizures and coma. It should be kept in mind that insulinoma is the most common cause of hypoglycemia associated with endogenous hyperinsulinism.