Glioblastoma multiforme after radiotherapy for acromegaly.

A case of glioblastoma multiforme that occurred 14 years after radiotherapy for acromegaly is presented. The striking correspondence between the anatomy of the tumor and the geometry of the radiation ports is suggestive of a causal relationship. Previously reported cases of radiation-associated glioma are reviewed, and a brief appraisal of the evidence for induction of these lesions by radiation is presented. The differentiation of radiation-associated neoplasms from radionecrosis is also discussed.