epithelial cyst

cyst (sist)

1. bladder.

2. an abnormal closed epithelium-lined cavity in the body, containing liquid or semisolid material.

3. a stage in the life cycle of certain parasites, during which they are enveloped in a protective wall.

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adventitious cyst  one formed about a foreign body or exudate.

alveolar cysts  dilatations of pulmonary alveoli, which may fuse by breakdown of their septa to form pneumatoceles.

aneurysmal bone cyst  a benign, rapidly growing, osteolytic lesion, usually of childhood, characterized by blood-filled cystic spaces lined by bony or fibrous septa.

arachnoid cyst  a fluid-filled cyst between the layers of the leptomeninges, lined with arachnoid membrane, usually in the sylvian fissure.

Baker cyst  a swelling behind the knee due to escape of synovial fluid that has become enclosed in a sac or membrane.

Blessig cysts  cystic spaces formed at the periphery of the retina.

blue dome cyst  a benign retention cyst of the breast which shows a blue color.

Boyer cyst  an enlargement of the subhyoid bursa.

branchial cyst  one arising in the lateral aspect of the neck, from epithelial remnants of a branchial cleft (pharyngeal groove), usually between the second and third pharyngeal arches.

bronchogenic cyst  a congenital cyst, usually in the mediastinum or lung, arising from anomalous budding during formation of the tracheobronchial tree, lined with bronchial epithelium that may contain secretory elements.

chocolate cyst  one having dark, syrupy contents, resulting from collection of hemosiderin following local hemorrhage.

choledochal cyst  a congenital cystic dilatation of the common bile duct, which may cause pain in the right upper quadrant, jaundice, fever, or vomiting, or be asymptomatic.

congenital preauricular cyst  one due to imperfect fusion of the first and second branchial arches in formation of the auricle, communicating with an ear pit on the surface.

dentigerous cyst  a fluid-containing odontogenic cyst surrounding the crown of an unerupted tooth.

dermoid cyst  a teratoma, usually benign, characterized by mature ectodermal elements, having a fibrous wall lined with stratified epithelium, and containing keratinous material, hair, and sometimes material such as bone, tooth, or nerve tissue; found most often in the ovary.

duplication cyst  a congenital cystic malformation of the alimentary tract, consisting of a duplication of the segment to which it is adjacent, occurring anywhere from the mouth to the anus but most frequently affecting the ileum and esophagus.

echinococcus cyst  hydatid c.

enteric cyst , enterogenous cyst a cyst of the intestine arising or developing from a fold or pouch along the intestinal tract.

epidermal cyst  a benign cyst derived from the epidermis or the epithelium of a hair follicle; it is formed by cystic enclosures of epithelium within the dermis, filled with keratin and lipid-rich debris.

epidermal inclusion cyst  a type of epidermal cyst occurring on the head, neck, or trunk, formed by keratinizing squamous epithelium with a granular layer.

epidermoid cyst 

1. epidermal c.

2. a benign tumor formed by inclusion of epidermal elements, especially at the time of closure of the neural groove, and located in the skull, meninges, or brain.

epithelial cyst 

1. any cyst lined by keratinizing stratified squamous epithelium, found most often in the skin.

2. epidermal c.

exudation cyst  one formed by an exudate in a closed cavity.

follicular cyst  one due to occlusion of the duct of a follicle or small gland, especially one formed by enlargement of a graafian follicle as a result of accumulated transudate.

globulomaxillary cyst  one within the maxilla at the junction of the globular portion of the medial nasal process and the maxillary process.

hydatid cyst  the larval cyst stage of the tapeworms Echinococcus granulosus and E. multilocularis, containing daughter cysts with many scoleces.

keratinizing cyst  one arising in the pilosebaceous apparatus, lined by stratified squamous epithelium and containing largely macerated keratin and often sufficient sebum to render the contents greasy or rancid.

lutein cyst  a cyst of the ovary developed from a corpus luteum.

median anterior maxillary cyst  one in or near the incisive canal, arising from proliferation of epithelial remnants of the nasopalatine duct.

median palatal cyst  one in the midline of the hard palate, between the lateral palatal processes.

meibomian cyst  a cyst of the meibomian gland, sometimes applied to a chalazion.

mucus retention cyst  a mucus-containing retention cyst caused by blockage of a salivary gland duct.

multilocular cyst 

1. a cyst containing several loculi or spaces.

2. a hydatid cyst with many small irregular cavities that may contain scoleces but generally little fluid.

3. a thick-walled cyst in the kidney, found in clusters and usually unilaterally. In children it contains blastema and may develop into a Wilms tumor.

myxoid cyst  a nodular lesion usually overlying an interphalangeal finger joint, consisting of focal mucinous degeneration of collagen of the dermis; not a true cyst, it lacks an epithelial wall and does not communicate with the underlying synovial space.

Naboth's cysts , nabothian cysts see under follicle.

nasoalveolar cyst , nasolabial cyst a fissural cyst arising outside the bones at the junction of the globular portion of the medial nasal process, lateral nasal process, and maxillary process.

odontogenic cyst  one derived from epithelium, usually containing fluid or semisolid material, which develops during various stages of odontogenesis; nearly always enclosed within bone.

osseous hydatid cysts  hydatid cysts formed by the larvae of Echinococcus granulosus in bone, which may become weakened and eroded by the exuberant growth.

parasitic cyst  one forming around larval parasites (tapeworms, amebas, trichinae), such as a hydatid cyst.

periapical cyst  a periodontal cyst involving the apex of an erupted tooth.

periodontal cyst  one in the periodontal ligament and adjacent structures, usually at the apex of the tooth (periapical c.).

pilar cyst  an epithelial cyst of the scalp, almost identical to an epidermal cyst, arising from the outer root sheath of the hair follicle.

piliferous cyst , pilonidal cyst a hair-containing sacrococcygeal dermoid cyst or sinus, often opening at a postanal dimple.

radicular cyst  an epithelium-lined sac at the apex of a tooth.

Rathke's cysts , Rathke's cleft cysts groups of epithelial cells forming small colloid-filled cysts in the pars intermedia of the pituitary gland; they are vestiges of Rathke's pouch and are closely related to craniopharyngiomas.

retention cyst  one caused by blockage of the excretory duct of a gland, so that glandular secretions are retained.

sarcosporidian cyst  sarcocyst (2).

sebaceous cyst  a retention cyst of a sebaceous gland, containing cheesy yellow material, usually on the face, neck, scalp, or trunk.

solitary bone cyst  a pathologic bone space in the metaphyses of long bones of growing children; it may be either empty or filled with fluid and have a delicate connective tissue lining.

sterile cyst  a true hydatid cyst that fails to produce brood capsules.

subchondral cyst  a bone cyst within the fused epiphysis beneath the articular plate.

sublingual cyst  ranula.

tarry cyst 

1. one resulting from hemorrhage into a corpus luteum.

2. a bloody cyst resulting from endometriosis.

tarsal cyst  chalazion.

theca-lutein cyst  a cyst of the ovary in which the cystic cavity is lined with theca interna cells.

unicameral bone cyst  solitary bone c.

wolffian cyst  a cyst of the broad ligament developed from vestiges of the mesonephros.

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epithelial cyst,

1 any cyst lined by keratinizing stratified squamous epithelium, found most often in the skin.

2 epidermal cyst.