P0170 - Expect the Unexpected: An Unusual Case of Insulinoma

A 73-year-old male with no significant medical history presented with symptoms of worsening dizziness and generalized fatigue since April 2023. He experienced recurrent episodes that disrupted his daily life. He reported that during these episodes, he would drink juice or eat to return to baseline but otherwise denied any palpitations, presyncope, confusion, urinary or bowel incontinence, postural hypotension, focal neurologic deficits, abdominal pain, nausea/vomiting, change in bowel habits, and weight changes. He was referred to the hospital for further evaluation. Management of hypoglycemia required a multidisciplinary approach. Glucose levels were stabilized with IV dextrose (D5NS and D10), IM glucagon, and oral glucose tabs, with frequent adjustments. Frequent small, carbohydrate-rich meals, particularly before bedtime, and continuous glucose monitoring were implemented. Initial treatment involved carbohydrates and diazoxide, which inhibits insulin secretion from pancreatic beta cells. Our patient was initiated on diazoxide. However, diazoxide and D10 were minimally effective and caused hyponatremia, complicating the hospital course. He was transitioned to everolimus, an mTOR kinase inhibitor with antiproliferative effects, resulting in some symptom improvement before transfer to a more specialized facility. The patient still experienced occasional nocturnal hypoglycemia, but felt well overall. For patients with hepatic metastases and refractory hypoglycemia, liver-directed therapies are considered. He underwent bland hepatic artery embolization for control of liver tumor burden and was continued on everolimus, supplemented with octreotide as a combination therapy. The patient appears to be tolerating well with minimal side effects.