Teratoma

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teratoma

[‚ter·ə′tō·mə]
(medicine)
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.

Teratoma

 

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.

REFERENCE

Klinicheskaia onkologiia detskogo vozrasta. Edited by M. V. Volkov. Moscow, 1965. (Contains bibliography.)
References in periodicals archive ?
Zielinski, "Osteocartilaginous choristoma of the tongue: clinical and histopathologic considerations," Journal of Oral Surgery, vol.
Wang, "Ocular choristomas," Survey of Ophthalmology, vol.
A diagnosis of osseous choristoma requires histopathology.
Salivary gland choristoma in the buccinator muscle: A case report and literature review.
Liguori, "Choroidal osteoma (osseous choristoma): an atypical case," British Journal of Ophthalmology, vol.
Lingual osseous choristoma: A study of eight cases and review of the literature.
Choristomas are benign congenital lesions that consist of an over growth of normal tissue in an abnormal location (Oakman et al.
(5.) Park JM, Kim DS, Kim J, Lee MG, Oh SH: Epibulbar complex choristoma and hemimegalencephaly in linear sebaceous naevus syndrome.
Allon, "A comparative study of oral hamartoma and choristoma," Journal of Interdisciplinary Histopathology, vol.
Choristoma generally consists of heterotopic tissue that is microscopically normal.
Ectopic liver or Choristoma is a rare condition in which the hepatic tissue is located at a site away from its usual anatomical location.