- Human pathology

Home > G. Tumoral pathology > teratoma


Wednesday 10 March 2004


Definition: Teratomas are neoplasms comprised of mixed elements derived from the three germ cell layers.

Teratoma is a complex tumor composed of a collection of heterogeneous cells and/or organoid structures reminiscent of normal derivatives of the germ cell.

It occurs in both male and female genital systems and other organs along the midline of the body, with similar morphology and classification.

Ovarian teratomas constitute 15%-20% of all ovarian tumors.

Benign mature teratoma has mature tissue deriving from two or more germ cell layers, while immature malignant teratoma has both mature and immature elements, especially immature neuroepithelial elements. Furthermore, the third variant, the monodermal teratoma, is composed of only one specialized tissue, such as thyroid tissue.


- Gastric teratoma in a 1yo male

A teratoma is generally defined as a tumor arising from pluripotent cells, and it is precisely the heterogeneity of tissues present in such a tumor that best characterizes it; it is also commonly accepted that a teratoma must contain derivatives of more than one blastodermic layer, according
to traditional concepts of embryonic ontogenesis.

Microscopical types

- mature teratoma

According to age

- fetal teratoma
- neonatal teratoma

According to the localization

-  gonadal teratoma

- extragonadal teratoma



- mature ovarian teratoma (by Washington Deceit)

@<@object width="425" height="350">@<@param name="movie" value="">@<@/param>@<@param name="wmode" value="transparent">@<@/param>@<@embed src="" type="application/x-shockwave-flash" wmode="transparent" width="425" height="350">@<@/embed>@<@/object>

See also

- Tumors