Teratoma

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A teratoma is a type of tumor that derives from pluripotent germ cells. The word comes from a Greek term meaning roughly "monster tumor". Teratomata usually start from cells in the testes in men, the ovaries in women and in the sacrum in children. The designation teratoma refers to a group of complex tumors having various cellular or organoid components reminiscent of normal derivatives from more than one germ layer. Teratomata are divided into three categories: (1) mature (benign), (2) immature (malignant), and (3) monodermal or highly specialized.

Teratomata often contain well-differentiated cells which can result in tissues growing in a teratoma which are quite different from the surrounding tissue—ovarian teratomata have been known to grow hair and teeth. Such a benign cystic teratoma is often termed a dermoid cyst, nowadays more correctly termed a mature teratoma. Some teratomata may contain a mixture of well-differentiated, mature tissues as: respiratory epithelium, hair follicle, fat tissue or mature nervous tissue. Immature teratomata of the ovary have a malignant potential in line with the amount of neuroblastic tissue present.

Testicular teratomata are generally less well-differentiated, and have a worse prognosis (chances of recovery are not as high).

Some teratomata secrete the "pregnancy hormone" human chorionic gonadotropin (HCG), which can be used in clinical practice to follow-up successful treatment or relapse in patients with a known HCG-secreting teratoma. It is not recommended as a diagnostic marker.

Some teratomata secrete thyroxine, in some cases to such a degree that it can lead to clinical hyperthyroidism in the patient.

In light of the ethical issues surrounding the source of human stem cells, teratomas are being looked at as an alternative source for research since they lack the potential to grow into functional human beings.

Struma ovarii

Struma ovarii (literally: goiter of the ovary) is a rare specialized type of teratoma present in the ovary that contains benign thyroid tissue. To be classified as a struma ovarii, thyroid tissue must be the predominant histology. Malignant transformation of struma ovarii is rare, occurring in only 5% of cases.

Appearances in popular culture

In season 2, episode 7 of Grey's Anatomy a man with a teratoma is admitted who believes that he is pregnant.
In the film My Big Fat Greek Wedding, Aunt Voula tells a story about "a lump on the back of [her] neck" that contained "teeth, and a spinal column", probably a teratoma.

External links

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