| dentigerous cyst | most common follicular odontogenic cyst. Occurs in relation to a partially erupted or unerupted tooth with at least the crown of the tooth to which the cyst is attached protruding into the cystic cavity. May give rise to an ameloblastoma and, in rare instances, undergo malignant transformation. (12 Dec 1998) |
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| synovial cyst | A nodular, tumourlike lesion in or about a tendon sheath or joint capsule, especially of the hands, wrists, or feet. It is not a true cyst as it lacks an epithelial wall, and it does not communicate with the underlying synovial space. The lesion represents a focal accumulation of mucin in the dermis of the dorsal aspect of the distal phalanges or, less often, other portions of the extremities. (12 Dec 1998) |
| synovial cyst, popliteal | A swelling in the space behind the knee (the popliteal space). The swelling is composed of a membrane-lined sac filled with synovial fluid that has escaped from the joint. Commonly called baker's cyst. (12 Dec 1998) |
| dermoid cyst | A collection of cancerous cells which form cysts that contain one or more of the three primary embryonic germ layers: skin, hair or teeth. (27 Sep 1997) |
| dermoid cyst of ovary | A common benign cystic teratoma of the ovary, lined for the most part by skin, and containing hair and sebum, but also usually containing a variety of other well differentiated structures within a small inwardly projecting mass of solid tissue. (05 Mar 2000) |
| dermoid cyst of the ovary | Tumours that develop from a totipotential germ cell (a primary oocyte) retained within the ovary. Being totipotential, that cell can give rise to all orders of cells necessary to form mature tissues and often recognizable structures such as hair, bone and sebaceous (oily) material, neural tissue and teeth. Dermoid cysts may occur at any age but the prime age of detection is in the childbearing years. The average age is 30. Up to 15% of women with ovarian teratomas have them in both ovaries. Dermoid cysts can range in size from a centimeter (less than a half inch) up to 45 cm (17 inches) in diameter. They can cause the ovary to twist (torsion) and imperil its blood supply. Although the large majority (about 98%) of ovarian teratomas are benign, the remaining fraction (about 2%) becomes malignant. The larger the dermoid, the greater the risk of rupture with spillage of the greasy contents which can create problems with adhesions, pain etc. Removal is usually the treatment of choice by laparotomy (surgery) or laparoscopy (with a scope). Dermoid cysts of the ovary are also called simply dermoids or ovarian teratomas. (12 Dec 1998) |
| distention cyst | A cyst resulting from some obstruction to the excretory duct of a gland. Synonym: distention cyst, secretory cyst. (05 Mar 2000) |
| duplication cyst | A congenital cystic malformation attached to or originating from any part of the alimentary canal, from the base of the tongue to the anus, which reproduces the structure of the adjacent alimentary tract. (05 Mar 2000) |
| implantation cyst | Intradermal or subcutaneous saclike structure, the wall of which is stratified epithelium containing keratohyalin granules. (12 Dec 1998) |
| incisive canal cyst | A cyst in or near the incisive canal, arising from proliferation of epithelial remnants of the nasopalatine duct; the most common maxillary development cyst. Synonym: median anterior maxillary cyst, nasopalatine duct cyst. (05 Mar 2000) |
| inclusion cyst | Intradermal or subcutaneous saclike structure, the wall of which is stratified epithelium containing keratohyalin granules. (12 Dec 1998) |
| involution cyst | A mammary cyst occurring at the menopause, due to fibrocystic disease. (05 Mar 2000) |
| odontogenic cyst | A cyst derived from odontogenic epithelium. Origin: odont-+ G. Genos, birth, origin, + suffix -ic, pertaining to (05 Mar 2000) |
| odontogenic cyst, calcifying | A mixed radiolucent-radiopaque lesion of the jaws with features of both a cyst and a solid neoplasm. It is characterised microscopically by an epithelial lining showing a palisaded layer of columnar basal cells, presence of ghost cell keratinization, dentinoid, and calcification. (12 Dec 1998) |
| oil cyst | A cyst resulting from loss of the epithelial lining of a sebaceous, dermoid, or lacteal cyst, or from the subcutaneous injection of oil or fat material. (05 Mar 2000) |