Malignant teratoma in the brain. An immunohistochemical study.

A case of intracranial malignant teratoma found in a 27-year-old man was reported. This unique tumor was found in the right frontal lobe separated from the pineal region and revealed various tissue components such as stratified squamous epithelium, glandular tissues, neuron, glia, ependyma, fibromuscular tissue, cartilage, bone, hemangiomatous lesion, melanin-laden cells, and some germ cell components. An immunohistochemical study demonstrated the presence of S-100 protein, glial fibrillary acidic protein (GFAP), neuron-specific enolase (NSE), carcinoembryonic antigen (CEA), and Factor VIII in some tumourous components. In particular, the distribution of S-100 protein in some germ cells suggested the possibility of the neuroectodermal origin of the germ cells or, alternatively, differentiation to the neuroectoderm.