Pediatric craniopharyngioma: when hypoglycemia reveals a brain tumor. Illustrative case.

backgroundCraniopharyngiomas (CPs) usually manifest with symptoms of intracranial hypertension secondary to obstructive hydrocephalus, visual disturbances, or growth failure. Hypoglycemia as the sentinel presentation is exceptionally rare and reflects hypothalamic-pituitary dysfunction. OBSERVATIONS: A previously healthy 4-year-old girl presented with progressive headache and vomiting for 4 days, followed by coma (Glasgow Coma Scale score 6). Emergency testing revealed profound hypoglycemia (capillary glucose 40 mg/dL [2.2 mmol/L]); consciousness returned rapidly after an intravenous dextrose bolus was administered. Because she had been vomiting, the hypoglycemia was initially attributed to malnutrition secondary to poor oral intake. However, recurrence of hypoglycemia within 24 hours prompted further evaluation. Abdominal CT excluded insulinoma and adrenal tumors. Endocrine testing revealed low morning cortisol and free thyroxine with inappropriately low thyroid-stimulating hormone, consistent with central adrenal insufficiency and hypothyroidism, while other hypothalamic-pituitary axes were preserved. Brain MRI showed a cystic sellar-suprasellar mass displacing the optic chiasm. Gross-total resection was achieved via a pterional approach. Histology confirmed an adamantinomatous CP. Postoperatively, hypoglycemia resolved, and the patient remained stable on hydrocortisone and levothyroxine replacement. LESSONS: CP, although relatively frequent, may exceptionally present with severe recurrent hypoglycemia and coma. Unexplained pediatric hypoglycemia warrants prompt endocrine evaluation and sellar imaging. Early recognition and multidisciplinary management (neurosurgery and endocrinology teams) are crucial for favorable outcomes. https://thejns.org/doi/10.3171/CASE25727.