TERATOMAS have been the subject of innumerable scientific and philosophic speculations since the inception of oncology. Their bizarre disorganization of structure and their even more bizarre approach to organogenesis have long aroused great interest among pathologists and embryologists.
Teratoma, literally a wondrous or monstrous growth, may be defined as a tumor containing tissues derived from two or more germ layers Most body tissues have been described in these tumors, and it has been said that the teratoma may well serve for a review of histology.1 Characteristically, however, gonadal tissues are hardly ever seen, and certain other tissues, such as liver, very rarely. Skin, bone, cartilage, connective tissue elements, epithelium of the respiratory and gastrointestinal tracts, smooth and striated muscle and glial and nerve tissues may all be present in abundance. These tissues may be mature or immature, the latter constituting the malignant, embryonal teratoma; but even the adult tissues