RF05 | PSUN365 Insulinoma: A Case Report of a Rare Functioning Neuroendocrine Tumor

: Insulinoma is a rare functional neuroendocrine tumor that causes inappropriate release of insulin, resulting in symptoms of hypoglycemia which would resolve promptly following glucose administraton. Its incidence is 1 to 3 per 1,000,000 population per year. CASE PRESENTATION: This study reports on a 64 year old female with no known co-morbidities who was seen in the endocrinology clinic due to episodes of blurring of vision, lightheadedness and shakiness. Glucose levels as low as 40mg/dL were detected with glucometer during these episodes. Symptom would improve after eating carbohydrate rich food. Symptom onset was 4 years prior to consult. Patient also reported weight gain as she would over-eat to treat her symptoms. The patient came in for evaluation and management of Hypoglycemia. Blood tests revealed high insulin (146.60 uU/mL; reference range: 5.00–10.00 uU/mL) and C-peptide level (7.45 ng/mL; reference range: 0.78–5.19 ng/mL) despite low plasma glucose level (36 mg/dL). Dynamic CT scan of the pancreas revealed an arterially enhancing nodule with intralesional calcification in the distal pancreatic body for which an insulinoma is considered. She underwent distal pancreatectomy and her symptoms showed complete resolution. Surgical pathology was consistent with well differentiated Neuroendocrine tumor. CONCLUSION: Clinicians should have a high index of suspicion for Insulinoma in patients with history of recurrent episodes of blurring of vision, lightheadedness and shakiness, particularly if these symptoms would resolve after food intake. Such condition entails proper and timely diagnosis, localization of the tumor and treatment and involves several specialties. Presentation: Saturday, June 11, 2022 1:36 p.m. - 1:41 p.m., Sunday, June 12, 2022 12:30 p.m. - 2:30 p.m.