[Cerebral radionecrosis discovered 32 years after conventional irradiation therapy for a pituitary adenoma (author's transl)].

A case of late radiation lesions of the brain was discovered 32 years after conventional X Ray therapy for pituitary adenoma. The major clinical picture was made of dementia and slight hypothalamic and pituitary dysfunction. Extensive bone-necrosis of the skull was observed. A defect of the sella led to recurrent meningitis. Segmental atheromatous lesions of cortical arteries are supposed to be induced by the photonic radiations. Intra parenchymatous lesions were slightly of the necrotic type and mainly of the degenerative one. Severe hyalin and calcic degeneration of small vessels was observed as well as extensive demyelination. The role of vascular and metabolic effects in the genesis of these late radiation lesions is discussed.