Also found in: Dictionary, Thesaurus, Medical, Wikipedia.
Related to Teratoma: Sacrococcygeal teratoma


A true neoplasm composed of bizarre and chaotically arranged tissues that are foreign embryologically as well as histologically to the area in which the tumor is found.



a neoplasm occurring in man and animals that results from the impaired embryonic development of tissues. Found mainly in children and adolescents, it is localized in the sex glands and occasionally in other organs and parts of the body. A teratoma generally consists of different types of tissue, including connective, epithelial, muscular, and neural tissue, and may include such differentiated derivatives of these tissues as teeth and hair.

The most complex teratomas in terms of composition and structure are those that have developed from early blastomeres or from primary sex cells that are totipotential, or able to develop into any type of body tissue. Teratomas that arise at later stages of embryonic development (after gastrulation) are limited in composition by the formative potential of the embryonic germ layer or organ from which the teratomas originate. Simple, relatively benign teratomas are distinguished from teratoblastomas— malignant tumors composed of tissues of embryonic structure and lacking a tendency to differentiate. Simple teratomas are also distinguished from teratoids—developmental defects that are not tumors but that may develop into tumors. Teratomas may become carcinomas or sarcomas.


Klinicheskaia onkologiia detskogo vozrasta. Edited by M. V. Volkov. Moscow, 1965. (Contains bibliography.)
References in periodicals archive ?
Paraneoplastic anti-N-methyl-D-aspartate receptor encephalitis associated with ovarian teratoma.
An ovarian teratoma develops from a totipotential germ cell (a primary oocyte) that is retained within the ovary.
Por otra parte, cuando hay una conjuncion grave los gemelos pueden fusionarse en un conglomerado de tejidos que imita un embarazo unico, lo cual puede confundirse con fetus in fetu o con teratoma.
Germ cell tumours other than teratomas are relatively rare.
The preoperative diagnosis of a JGCT is difficult, and it is usually initially diagnosed as a teratoma.
The ascitic fluid did not show any malignancy and the final diagnosis was a left ovarian benign cystic teratoma and right ovarian papillary serous cystadenoma.
In this study, a rare, mature cystic teratoma that was associated with an anterior intrathoracic meningocele and that developed in the posterior mediastinum is presented.
The initial biological event that leads to teratoma is not yet understood.
Teratoma and mixed tumors were found to occur in 7.
To our knowledge, these are the first reports of ovarian teratoma and adrenal carcinoma causing clinical signs of IO in cattle.
Histopathology report confirmed mature cystic teratoma.