What is "dermoid cyst"

Dermoid \Der"moid\, a. [Derm + -oid: cf. F. dermo["i]de.] Same as Dermatoid.

Dermoid cyst (Med.), a cyst containing skin, or structures connected with skin, such as hair.

n. (context pathology English) A type of teratoma or tumour, usually benign. It is in the form of a cyst or sac, and contains skin and sometimes hair, nails, teeth or other tissue.

n. a cystic tumor (usually benign) with an epithelium-lined wall and a cavity containing other material

A dermoid cyst is a teratoma of a cystic nature that contains an array of developmentally mature, solid tissues. It frequently consists of skin, hair follicles, and sweat glands, while other commonly found components include clumps of long hair, pockets of sebum, blood, fat, bone, nails, teeth, eyes, cartilage, and thyroid tissue.

As dermoid cysts grow slowly and contain mature tissue, this type of cystic teratoma is nearly always benign. In those rare cases wherein the dermoid cyst is malignant, a squamous cell carcinoma usually develops in adults, while infants and children usually present with an endodermal sinus tumor.