Cavernous angioma associated with oligo-astrocytoma-like proliferation. Report of two cases and review of the literature with a reappraisal of the term "angioglioma".

Reporting two cases of cavernous angioma closely associated with oligo-astrocytoma we were stimulated to revise the proper use of the term "angioglioma", introduced by Councilman 80 years ago7. In the past this term was often used in a merely descriptive sense i.e. either to give a name to an exceptional coincidence of AVM and glioma or simply to describe a hypervascularized glioma. Today, according to the majority of authors, such a use of this term has to be rejected as inappropriate. Occasionally however the term angioglioma has been used to designate a true mixed composite neoplasm developed after the transformation of both glial and angiogenic elements determined by simultaneously or consecutively acting (even possibly intermingled) oncogenic factors. Among reported cases claimed to be examples of "true" angioglioma, the association cavernomaoligodendroglioma/astrocytoma seems the most intriguing besides being also the most frequent one. Opinions about this topic however did continue to be unequivocal. While some authors regarded the oligodendroglial proliferation associated with AVM as merely reactive or malformative, others considered it as truly neoplastic putting forward the hypothesis of a common viral or genetic aetiology for both AVM and glioma.