Experimental Brain Tumors I. Tumors Produced with Methylcholanthrene*

Efforts to produce intracranial neoplasia by various chemical carcinogens have been attended with scant success prior to the work of Seligman and Shear (2). By intracerebral implantation of pellets of 2o-methylcholanthrene, these workers produced i i gliomas and 2 fibrosarcomas in a series of 2o male mice of the C3H strain. Seligman and Shear reported also successful subcutaneous transplantation of several of these tumors, one of which was stated to be a glioma. Utilizing the same technic, the present writers reported a preliminary experiment (3) in which they found u6 intracranial tumors in 51 C3H mice. These tumors, occurring during the first io months of the experiment, consisted of oligodendroglioma, glioblastoma multiforme, medulloblastoma, unclassified glioma, and meningeal sarcoma. More recently Peers (1) implanted cholesterol pellets containing lO per cent methylcholanthrene in the brains of 99 mice, of which 87 survived into the tumorbearing period. In all, 32 intracranial tumors were produced--i 7 sarcomas and 15 gliomas. These observations were significant in that they suggested the future possibility of studying the incidence, histiogenesis, and growth behavior of experimentally induced primary brain tumors. From such a study it was felt that certain deductions could be drawn regarding the human counterparts of these neoplasms. The present investigation was thus undertaken for a threefold purpose; namely, the determination of the incidence, the histiogenetic origin, and the growth behavior of experimental brain tumors.