branchial 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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branchial cyst

Etymology: Gk, branchia, gills, kystis, bag

a cyst derived from a branchial remnant in the neck.

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branchial [brang´ke-al]

pertaining to, or resembling, gills of a fish or derivatives of homologous parts in higher animals.

branchial cyst a cyst formed deep within the neck from an incompletely closed pharyngeal groove (branchial cleft), usually between the second and third pharyngeal arches (branchial arches). These two arches grow together and enclose the cervical sinus in the neck, which is a common site of a branchial cyst. Called also branchiogenic or branchiogenous cyst.

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cyst [sist]

1. bladder.

2. an abnormal closed epithelium-lined sac in the body that contains a liquid or semisolid substance. Most are harmless, but they should be removed when possible because they occasionally may change into malignant growths, become infected, or obstruct a gland. There are four main types of cysts: retention cysts, exudation cysts, embryonic cysts, and parasitic cysts.

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

adventitious cyst pseudocyst (def. 1).

alveolar c's dilatations of pulmonary alveoli, which may fuse by breakdown of their septa to form large air cysts (pneumatoceles).

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 on the back of the knee, due to escape of synovial fluid that has become enclosed in a sac of membrane.

Bartholin cyst a mucus-filled cyst of a Bartholin gland, usually developing as a consequence of an obstruction of the duct by trauma, infection, epithelial hyperplasia, or congenital atresia or narrowing.

Blessig c's cystic spaces formed at the periphery of the retina.

blue dome cyst

1. a benign retention cyst of the breast that shows a pale blue color. See also cystic disease of breast.

2. a cyst due to endometriosis, found in healed wounds such as those of an episiotomy or an incision for a cesarean section; it is usually found in the vaginal fornix or on the cervix.

Boyer cyst an enlargement of the subhyoid bursa.

branchial cyst (branchiogenic cyst) (branchiogenous cyst) see branchial cyst.

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 filled with hemosiderin, causing a dark color, following local hemorrhage, such as may occur in the ovary in ovarian endometriosis.

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.

daughter cyst a small parasitic cyst developed from the walls of a larger cyst.

dentigerous cyst an odontogenic cyst surrounding the crown of a tooth, originating after the crown is completely formed.

dermoid cyst see dermoid cyst.

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 cyst.

embryonic cyst one developing from bits of embryonic tissue that have been overgrown by other tissues, or from developing organs that normally disappear before birth. An example is a branchial cyst.

enteric cyst (enterogenous cyst) a cyst of the intestine arising or developing from some fold or pouch along the intestinal tract. Called also enterocyst and enterocystoma.

epidermal cyst (epidermoid cyst) an intradermal or subcutaneous cyst containing keratinizing squamous epithelium; it arises from occluded hair follicles. Called also wen.

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

epithelial cyst

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

2. epidermal cyst.

exudation cyst a cyst formed by the slow seepage of an exudate into a closed cavity.

false cyst pseudocyst (def. 1).

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.

hydatid cyst the larval stage of the tapeworms Echinococcus granulosis and E. multilocularis; each one contains daughter cysts that have many scoleces (mouths). See also hydatid disease. Called also echinococcus cyst and hydatid.

inclusion cyst one formed by the inclusion of a small portion of epithelium or mesothelium within connective tissue along a line of fusion of embryonic processes; several types are found in the oral and nasal regions.

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.

meibomian cyst 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 a distal interphalangeal finger joint in the dorsolateral or dorsomesial position, consisting of focal mucinous degeneration of the collagen of the dermis; not a true cyst, lacking an epithelial wall, it does not communicate with the underlying synovial space.

Naboth's c's (nabothian c's) cysts that occur when mucus-producing glands in the columnar epithelium of the uterine cervix become covered over by squamous epithelium resulting from metaplasia; they are usually found in the transformation zone of the cervix. Called also Naboth's or nabothian follicles.

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.

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.

perineurial cyst an outpouching of the perineurial space on the extradural portion of the posterior sacral or coccygeal nerve roots at the junction of the root and ganglion; it may cause low back pain and sciatica.

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

pilar cyst a type of epidermal cyst, almost always found on the scalp, arising from the outer root sheath of the hair follicle.

pilonidal cyst see pilonidal cyst.

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

Rathke's c's (Rathke's cleft c's) 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 a tumorlike accumulation of a secretion formed when the outlet of a secreting gland is obstructed. These cysts may develop in any of the secretory glands, such as the breast, pancreas, kidney, salivary or sebaceous glands, or mucous membranes.

sarcosporidian cyst sarcocyst (def. 2).

sebaceous cyst see sebaceous cyst.

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.

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

tarry cyst

1. one resulting from hemorrhage into a corpus luteum.

2. a bloody cyst resulting from endometriosis.

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

traumatic bone cyst a cavity (not a true cyst) formed in bone, particularly the mandible, in response to trauma. The hematoma precipitated by trauma is resorbed but bone is not replaced; the space formed is usually empty and lacks an epithelial lining.

unicameral bone cyst solitary bone cyst.

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

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cyst (sist),

n a pathologic space in bone or soft tissue containing fluid or semifluid material and, in the oral regions, almost always lined by epithelium.

cyst, aneurysmal bone

n a nonmalignant osteolytic lesion expanding a long bone or within a vertebra in which the space, filled with blood, is networked with fibrous tissue containing multinucleated giant cells.

cyst, apical periodontal,

n See cyst, periapical.

cyst, branchial,

n (branchial cleft cyst), a soft-tissue cyst usually seen on the lateral side of the neck, arising from epithelial illusions within the cervical lymph nodes. Microscopic examination shows the epithelial lining of stratified squamous epithelium surrounded by lymphoid tissue.

Branchial cyst.

cyst, calcifying odontogenic (Gorlin cyst),

n a cyst arising from odontogenic epithelium, with abundant production of keratin-containing ghost cells and areas of dystrophic calcification. This lesion has a predilection for young adults.

cyst, dental,

n See cyst, periodontal.

n See cyst, eruption.

cyst, dentigerous

n an epithelium-lined sac filled with fluid or semifluid material that surrounds the crown of an unerupted tooth or odontoma.

cyst, dentoalveolar,

n See cyst, periodontal.

cyst, dermoid

n an epithelium-lined sac with one or more skin appendages (hair follicles, sweat glands, sebaceous glands) in its wall. It may be found in the floor of the oral cavity. This lesion should not be confused with the teratomatous dermoid cyst of the ovary.

Dentigerous cyst.

cyst, developmental,

n a pathologic fluid sac that may be caused by infection or disease. See also cyst, dentigerous and cyst, odontogenic.

cyst, epidermoid

n a fluid-filled, epithelium-lined sac thought to arise from hair follicles of the skin.

cyst, eruption,

n a dentigerous cyst that causes a clinically evident bulging of the overlying alveolar ridge.

cyst, extravasation,

n See cyst, traumatic.

cyst, fissural,

n a cyst that arises from the enslaved epithelium in maxillary suture lines caused by fusion of the embryonic processes of the facial bones.

cyst, follicular

n See cyst, dentigerous.

cyst, gingival, of the adult,

n a rare gingival cyst, usually painless, that originates on dental laminar rests. It is usually categorized as an extra-osseous instance of a lateral periodontal cyst.

cyst, gingival, of the newborn,

n a keratin-filled benign cyst on the alveolar mucosa that is common among newborn infants. Similar to palatal cysts of the newborn.

cyst, globulomaxillary

n thought to have been a developmental fissural cyst arising in the area between the nasal process and maxillary process. It is now believed that all these lesions are actually other odontogenic cysts, such as odontogenic keratocysts or lateral periodontal cysts.

cyst, Gorlin,

n See cyst, calcifying odontogenic (Gorlin cyst).

cyst, hemorrhagic

n an extravasation cyst or lesion; traumatic bone cyst or lesion. This is not a true cyst but is probably a defect in the bone produced by trauma and repair. It appears as a definite radiolucent area with a sharply marked radiopaque border. It contains air and is lined by a thin endosteum. See also cyst, solitary bone.

cyst, incisive canal,

n See cyst, nasopalatine.

cyst, indefinite bone,

n See cyst, traumatic.

cyst, lateral,

n See cyst, periodontal.

cyst, lateral periodontal (botryoid odontogenic cyst),

n a noninflammatory cyst found in the tooth-generating tissue on the lateral surface of the root of a tooth.

cyst, median palatal,

n an epithelium-lined sac containing fluid; appears as a radiolucency in the midline of the palate. It is of developmental origin.

cyst, multilocular

n a follicular cyst containing many loculi, or spaces, and not associated with a tooth.

cyst, nasoalveolar

n a fluid-containing sac lined by epithelium and located at the ala of the nose. A developmental cyst, it may simulate a nasal or periapical abscess.

n a cyst arising within the nasopalatine canal. Radiographically it may appear as a heart-shaped radiolucency between the maxillary central incisors. Histologically it may show mucous cells and nerve bundles in addition to a lining of stratified squamous or respiratory epithelium. The incisive canal cyst and the cyst of the papilla incisiva are the recognized subtypes.

cyst, nonodontogenic,

n a soft tissue abnormality that may develop in any number of locations within the oral cavity but is not directly associated with a tooth.

cyst, odontogenic,

n an epithelium-lined sac produced from the tooth-forming tissues (e.g., primordial, dentigerous, and periodontal cysts).

cyst, palatal, of the newborn,

n a common developmental cyst found on the hard palates of most infants. It is small, white, and filled with keratin. Called Epstein's pearls when found on the midline of the palate, and Bohn's nodules when found elsewhere on the palate, though both types are the same.

cyst, periapical,

n a cyst that has a fibrous connective tissue wall and a lining of stratified squamous epithelium and that is attached to the apex of the root of a tooth with a nonvital pulp or a defective root canal filling.

cyst, periodontal (dental root cyst, dentoalveolar cyst, lateral cyst, periapical cyst),

n an epithelium-lined sac containing fluid usually found at the apex of a pulp-involved tooth. Lateral types occur less frequently along the side of the root.

cyst, primordial

n an epithelium-lined sac containing fluid and appearing as a radiolucency in the jaws. It is derived from an enamel organ before any hard tissue is formed.

n See cyst, periapical.

cyst, residual,

n an odontogenic cyst that remains within the jaw after the removal of the tooth with which it was associated. May be radicular or follicular.

cyst, root end,

n See cyst, periapical.

cyst, simple bone,

n a diseased bone cavity that forms around the roots of teeth, easily identifiable during radiologic exam. Of uncertain origin. Previously known as traumatic bone cyst and solitary bone cyst.

cyst, soft tissue,

n a broad classification of oral abnormalities that may include blisterlike obstructions of salivary glands and growths in the thyroglossal tract, lymph nodes, and epithelial cells on the floor of the oral cavity.

cyst, soft tissue developmental,

n a pathologic fluid sac that occurs in mucous membranes or other soft tissue of the body, as opposed to those occurring in bone or teeth. See also cyst, thyroglossal duct and cyst, lateral cervical.

cyst, solitary bone,

n See cyst, simple bone.

n an epithelium-lined sac containing fluid formed in portions of the incompletely involuted thyroglossal duct, which connects the primitive pharynx with the tongue in embryonic life. These cysts may appear in the midline at any region from the subhyoid to the base of the tongue.

cyst, traumatic bone,

n See cyst, simple bone.

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branchial, branchiogenic, branchiogenous

pertaining to, or resembling, gills of a fish or derivatives of homologous parts in higher forms.

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branchial arches

paired arched columns that bear the gills in lower aquatic vertebrates and which, in embryos of higher vertebrates, become modified into structures of the face, mandible, ear and neck.

branchial clefts

the clefts between the branchial arches of the embryo, formed by rupture of the membrane separating corresponding entodermal pouch and ectodermal groove.

branchial cyst

a cyst formed deep within the neck from an incompletely closed branchial cleft, usually located between the second and third branchial arches. The branchial arches develop during early embryonic life and are separated by four clefts. As the fetus develops, these arches grow to form structures within the head and neck. Two of the arches grow together and enclose the cervical sinus, a cavity in the neck. A branchial cyst may develop within the cervical sinus. Called also branchiogenic or branchiogenous cyst. Seen rarely in dogs as a slowly developing swelling in the pharyngeal area, filled with saliva.

branchial groove

an external furrow lined with ectoderm, occurring in the embryo between two branchial arches.

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branchial cyst

Branchial cleft cyst, see there