Biphasic malignant meningioma: a comparative genomic hybridization study.

To ascertain if a carcinoma-like component within a fibroblastic meningioma represented a metastatic carcinoma to a meningioma or malignant progression, we employed traditional immunohistochemical methods as well as comparative genomic hybridization (CGH) which compares chromosomal alterations. Vimentin and epithelial membrane antigen were strongly immunoreactive in both the fibroblastic and carcinoma-like components. The CGH profile in both components had similar chromosomal alterations, including losses of 1p, 14, 16p13-->p10 and 22.