Malignant Astrocytoma Arising 10 Years after Combined Treatment of Craniopharyngioma

Craniopharyngioma is the third most common intracranial tumor in childhood. Following surgery, virtually all patients present with hypopituitarism and are at considerable risk of tumor recurrence. Secondary tumors, however, are, rare, occurring usually 10 years after diagnosis and associated with poor prognosis. We report on a 5 year-old boy in whom craniopharyngioma was diagnosed due to unilateral visual loss. After surgery he underwent conventional radiation therapy with a total tumor dose of 55 Gy, and had hormonal support with DDAVP, thyroxine, and a variable dose of hydrocortisone. Growth velocity declined slowly in the first 4 years, but improved later on again without GH therapy despite abnormal provocative tests. At the age of 15 years he developed peripheral facial nerve palsy due to a malignant astrocytoma (WHO grade III/IV). Repeated conventional radiation therapy with an additional stereotactic boost and chemotherapy could not prevent the fatal outcome. This observation may temper the use of radiosurgery in benign intracranial tumors.