Endocrine Abstracts

Introduction: Insulinoma is a pancreatic tumor that induces hypoglycemia due to over secretion of Insulin. Common symptoms include headache, diplopia, palpitations, blurred vision and unconsciousness. Approximately 90% of insulinomas are benign. Insulinoma is characterized by the Whipple triad, which includes symptoms of hypoglycemia, concomitant plasma glucose of less than 50 mg/dl, and reversal of symptoms after correction of hypoglycemia.

Case presentation: We report a case of a 40-year-old female, married, who presented to us with fit-like activity for 8 years and low blood sugars for 3 years. The patient first experienced fit-like activity in 2015. It was characterized by tremors, and up rolling of eyes, followed by decreased responsiveness. She would remain drowsy for a few hours and then regain full consciousness after intravenous treatment, the record of which was unavailable. Anti-epileptic medications were started. Her symptoms resolved after a few weeks. She then experienced the same symptoms in 2017 that resolved simultaneously. Symptoms recurred in 2020; her random blood sugar level at that time was 35 mg/dl. Her symptoms resolved after intravenous treatment. She was hospitalized in 2023 and her lumbar puncture was done which showed predominant lymphocytic leukocytosis, anti-tuberculosis treatment (ATT) was started. Commencement of ATT also did not resolve her symptoms. After admission to our hospital, supervised hypoglycemia was induced with fasting; her fasting Insulin, C-peptide and cortisol levels were sent once the patient got symptomatic. Hypoglycemia was corrected with intravenous dextrose bolus after drawing a blood sample which led to the resolution of her symptoms. Her laboratory investigations ordered at the time of fasting were; Blood sugar: 28 mg/dl, Insulin: 42.8 mIU/l, C-peptide: 4.05 ng/ml, serum cortisol: 17.7 mg/dl. She fulfilled the Whipple triad and was diagnosed with insulinoma. CT scan abdomen with contrast was unremarkable. Insulinoma was localized in the pancreatic tail via endoscopic ultrasound and was ablated via ethanol. Post ablation, the patient’s blood sugars were normal. Her MRI brain and EEG were done to rule out any central pathology, and both were unremarkable. Her repeat CSF-DR was in the reference range with nil White-cell count. ATT was continued. She was then discharged and anti-epileptic medications were tapered off. She has had no fit-like activity post-discharge.

Conclusion: Our patient with Insulinoma was misdiagnosed with epilepsy. It led to inappropriate prescription of anticonvulsants. Therefore, we conclude that Insulinoma should be suspected in patients exhibiting fit-like activity associated with hypoglycemia. Appropriate clinical judgment is essential for timely management.