A rare case report of reversible glucose counterregulation in an insulinoma patient with type 2 diabetes.

Context: Insulinoma is a neuroendocrine tumor derived from pancreatic β -cells whose clinical manifestation is recurrent hypoglycemia. Insulinoma in a patient with preexisting diabetes is extraordinarily rare, and the unmasking of type 2 diabetes (TDM) after insulinoma surgery is even rarer.

Case Report: This article reports a 49-year-old male patient with insulinoma that masked the diagnosis of TDM.