Central diabetes insipidus and adipsia due to astrocytoma: diagnosis and management.

Adipsia and/or diabetes insipidus is rarely a direct complication of astrocytoma. We report a young man with recurrence of anaplastic astrocytoma who presented as severe hypernatremia. This case highlights key diagnostic and therapeutic challenges: (1) the interpretation of the response to exogenous vasopressin in a patient with steroid-induced hyperglycemia and (2) the potential risk of brain edema and herniation if excess water is prescribed along with vasopressin supplementation. The patient was successfully managed with prescribed fluid replacement, daily weights, and regular electrolyte monitoring but no exogenous vasopressin for 8 months until he succumbed to his tumor.