1290 Years of Undiagnosed Recurrent Hypoglycemia in a Child

Abstract

INTRODUCTION: Below we present a case of a child with an insulinoma, a rare and difficult to diagnose cause of hypogylcemia. CASE DESCRIPTION/METHODS: A previously healthy 12-year-old child presented to the emergency department with an unresponsive episode. Her father found her in bed, “unable to open her eyes” and extremely lethargic. Her blood sugar was noted to be less than 20 and she had ketones in her urine. Her glucose improved with oral intake and was discharged with a presumptive diagnosis of a well known cause of hypoglycemia in this age group, ketotic hypoglycemia. She remained well for around a year but then returned to the ED with lethargy. She was deemed have symptoms consistent with her originally diagnosed condition and was discharged. After an illness free period of 18 months, she presented to the ED with a low glucose of 33, high insulin of 14, and high c-peptide of 3.3. She had a negative CT scan was again discharged home. For the next few months, she having daily symptoms of fatigue and “cranky” behaviors, with only partial response to glucose intake. At age 16, after being seen by an endocrinologist, an insulinoma was considered as a possible diagnosis. MRI was ordered, but didn't detect a mass in the pancreas. Thus, GI was consulted for endoscopic ultrasound (EUS) and a 2 cm mass in the uncinate process was detected. FN-B of the pancreatic mass was consistent with neuroendocrine tumor. The patient had a surgical resection and, eventually, complete resolution of symptoms. DISCUSSION: Insulinomas are a very rare cause of hypoglycemia, with around 1 to 4 new cases occurring per million persons per year, and particularly uncommon in children with only limited number of published case reports. Classically, the “Whipple's triad” is expected with insulinoma: a low plasma glucose, symptoms consistent with hypoglycemia, relief of symptoms when the glucose is raised to normal. This patient did have certain aspects of the triad of symptoms, but she didn't always respond to glucose thus complicating diagnosis. This case is a reminder that, while rare, insulinoma is a important cause of hyperinsulinemic hypoglycemia in the pediatric population. Also important to know I is that while CT is generally considered first line for diagnosis of insulinoma and has good sensitivity and specificity and MRI has even better accuracy, neither test is perfect, thus EUS is sometimes required to identify lesions.