Insulinoma presenting as medically intractable temporal lobe epilepsy

We describe a female insulinoma patient who presented with recurrent attacks of abnormal behavior, confusion, and seizure. Her interictal EEG showed epileptiform discharges on the left temporal area, therefore she was initially misdiagnosed as temporal lobe epilepsy. In the video-EEG monitoring, hypoglycemic state was detected during the seizure attack, so the right diagnosis was made after the endocrinologic investigations. After surgical removal of the tumor, the patient became seizure-free, and no abnormality was found in the follow-up EEG after six months. Since insulinoma shares some common clinical and EEG features with complex partial seizure of temporal lobe origin, insulioma should be included in the differential diagnosis for medically intractable temporal lobe epilepsy.