Two cases of patients with unusual pleomorphic tumors in the meninges are reported. Histologically and immunohistologically, the tumor cells may be histiocytic in appearance. Computed tomography and magnetic resonance imaging scans, however, revealed no lesions in the parenchyma or in the meninges. The cytological examination of the cerebrospinal fluid revealed only a light lymphocytic reaction without tumor cells in both cases and thus led to misinterpretations as meningoencephalitis. One patient presented psychiatric symptoms. Related clinical problems and the possible histogenesis of the tumors are discussed.