Insulinomas are rare tumors with an incidence of approximately four cases per million person-years. Nineteen cases of insulinoma during pregnancy have been reported. Hypoglycemic symptoms usually appear during the first trimester. A 28-year-old primigravida was admitted at 6 weeks of gestation after referral for uncontrolled seizures. Her previous seizure work-up included a normal EEG and a normal magnetic resonance imaging of the brain. Elevated fasting insulin and C-peptide levels accompanied severe hypoglycemia. The patient was managed with glucose monitoring, frequent small meals, and rare doses of glucagon. Postpartum testing was consistent with insulinoma, and magnetic resonance imaging indicated a mass in the tail of the pancreas. During surgical exploration with intraoperative ultrasound, two insulinomas were removed from the tail of the pancreas. The hypoglycemic episodes resolved and the fasting glucose levels normalized. Insulinomas are rare in pregnancy and can be difficult to diagnose. Symptoms may resolve during the second and third trimesters, possibly due to changes in glucose metabolism associated with pregnancy. Misdiagnosis has been fatal. Careful management during pregnancy and aggressive treatment after delivery are essential.
Target audience: Obstetricians and Gynecologists, Family Physicians.
Learning objectives: After completion of this article, the reader will be able to describe the pathophysiology of an insulinoma, to list the potential tests used to make the diagnosis of insulinoma, and to outline potential treatment options for a patient with an insulinoma.