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.
McGraw-Hill Dictionary of Scientific & Technical Terms, 6E, Copyright © 2003 by The McGraw-Hill Companies, Inc.
The following article is from The Great Soviet Encyclopedia (1979). It might be outdated or ideologically biased.

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.)
The Great Soviet Encyclopedia, 3rd Edition (1970-1979). © 2010 The Gale Group, Inc. All rights reserved.