INTRODUCTION
Insulinoma, a prevalent functional pancreatic neuroendocrine tumor
(pNET), is characterized by specific insulin secretion, leading to
endogenous hyperinsulinemia and subsequently resulting in
hypoglycemia.[1] Insulinoma is the predominant cause of hypoglycemia
related to endogenous hyperinsulinemia, which occurs in approximately 1
to 4 individuals per million.[2] The primary clinical manifestations
of insulinoma include spontaneous hypoglycemia, psychiatric
abnormalities, and neurological symptoms such as impaired consciousness
and seizures.[3] While qualitative diagnosis of insulinoma is
straightforward, the challenge lies in localizing the often small and
hidden tumor. Some patients, despite traditional imaging, remain
undiagnosed or are misdiagnosed. Herein, in this report, we present a
case of insulinoma with an occult tumor and provide a comprehensive
review of the relevant literature, aiming to raise awareness among
clinicians regarding early diagnosis and treatment of insulinoma.