Radiation-associated meningioma in the elderly: development of meningioma with olfactory neuroblastoma recurrence 10 years after irradiation.

The pathogenesis of meningiomas is not established [1,2]. However, intracranial irradiation in childhood is a risk factor for the development of meningiomas later in life [2-6]. Children treated with irradiation for tinea capitis of the scalp showed an almost ten-fold increase in development of meningiomas relative to age-matched controls [2,3]. In a study of almost 18,000 children who survived for at least five years after receiving external beam radiation, 2.3% developed meningiomas within 17 years of follow-up [5]. Notably, meningioma formation after radiation therapy (RT) occurs almost exclusively in patients irradiated as children or young adults. Development of a radiation-associated meningioma (RAM) in patients who received RT in the sixth or seventh decade is very rare. For example, in studies including a total of 58 adults receiving RT, only two cases of RAM occurred in patients 50 years old or older [8,9].