Congenital craniopharyngioma and hypercalcemia induced by parathyroid hormone-related protein

To report a case of congenital craniopharyngioma and parathyroid hormone-related protein (PTHrP)-associated humoral hypercalcemia.

Details of this unusual case are reviewed, from detection of fetal hydrocephalus and a brain tumor, through cesarean delivery at 36 weeks of gestation, to subsequent laboratory studies, management, and confirmation of the diagnosis.

Although PTHrP has been well documented as a cause of humoral hypercalcemia of malignancy (HHM) in adult patients with cancer, HHM is uncommon in children. In addition, HHM has rarely been ascribed to nonmalignant tumors. To the best of our knowledge, we report the first case of a neonate with congenital craniopharyngioma and refractory hypercalcemia (peak ionized calcium level of 1.92 mmol/L; normal, 1.05 to 1.3) attributed to an elevated PTHrP value of 8.6 pmol/L (normal, less than 4.7). Intact parathyroid hormone was appropriately undetectable (less than 10 pg/mL; normal, 15 to 65). Despite calcitonin treatment, the hypercalcemia persisted. Although pamidronate infusion stabilized the serum calcium level, the baby did not survive.

The diagnosis of craniopharyngioma was confirmed at autopsy, and immunohistochemical studies substantiated that the craniopharyngioma produced PTHrP.