In the current study, IHC for vimentin and CK was particularly useful indistinguishing the papillated/anaplastic meningiomas and choroid plexus tumor fromcarcinomas, as these all exhibited a papillary growth pattern.52 Primary carcinomas in the brain are extremely rare and are suspected to arisefrom intracranial epidermoid or dermoid cysts.37 As no cysts were seen in any of the cases and have not been reported incattle in the literature, it is presumed that these carcinomas represent secondarymetastases. The gene discussed is VIM; the disease is choroid plexus neoplasm.