cyst

(redirected from fatty cyst)
Also found in: Dictionary, Thesaurus, Encyclopedia, Wikipedia.

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.
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.

cyst

(sist),
1. A bladder.
See also: pseudocyst.
2. An abnormal sac containing gas, fluid, or a semisolid material, with a membranous lining.
See also: pseudocyst.
[G. kystis, bladder]

cyst

(sist)
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.

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 
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.
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.

cyst

(sĭst)
n.
1. An abnormal membranous sac in the body containing a gaseous, liquid, or semisolid substance.
2. A sac or vesicle in the body.
3. Biology A small capsulelike sac that encloses certain organisms in their dormant or larval stage.
4. Botany A thick-walled resting spore, as in certain algae or fungi.

cyst

[sist]
Etymology: Gk, kystis, bag
a closed sac in or under the skin lined with epithelium and containing fluid or semisolid material, for example, a sebaceous cyst. It may or may not be infected. cystic, adj.

cyst

Medtalk Any closed sac, cavity, or capsule, usually filled with fluid or semisolid material, and lined by epithelium often contains liquid or semi-solid material Surgery A usually benign closed sac or capsule lined by epithelium, usually filled with fluid or semisolid material. See Aneurysmal bone cyst, Baker's cyst, Benign ear cyst, Blue domed cyst, Branchial cleft cyst, Bronchogenic cyst, Chocolate cyst, Dermoid cyst, Gartner's duct cyst, Giant acute pancreatic pseudocyst, Horn pseudocyst, Meibomian cyst, Multilocular renal cyst, Nabothian cyst, Odontogenic cyst, Odontogenic keratocyst, Pilonidal cyst, Pseudocyst, Rathke's cleft cyst, Sebaceous cyst, Synovial cyst, Thyroglossal duct cyst, Twisted ovarian cyst.

cyst

(sist)
1. An abnormal sac containing gas, fluid, or a semisolid material, with a membranous lining.
See also: pseudocyst
2. Larval stage of some cestodes.
[G. kystis, bladder]

cyst

(sist) [Gr. kystis, bladder, sac]
1. A closed sac or pouch with a definite wall, containing fluid, semifluid, or solid material. It is usually an abnormal structure resulting from developmental anomalies, obstruction of ducts, or parasitic infection.
2. In biology, a structure formed by and enclosing certain organisms in which they become inactive, such as the cyst of certain protozoans or of the metacercariae of flukes.

adventitious cyst

A cyst formed around a foreign body.

alveolar cyst

Dilation and rupture of pulmonary alveoli to form air cysts.

apical cyst

A cyst near the apex of the root of a nonvital tooth.

arachnoid cyst

An abnormal collection of cerebrospinal fluid within the arachnoid membrane. The cysts may compress nearby structures within the brain. In infants, they may cause headaches, altered mental status, learning disabilities, or enlargement of the head. In adults, they are an occasional cause of epilepsy.

Baker cyst

See: Baker cyst.

Bartholin cyst

See: Bartholin, Caspar (the younger)

blood cyst

Hematoma.

blue dome cyst

1. A mammary cyst containing light, straw-colored fluid, which appears blue when seen through the surrounding tissue.
2. A small dark-blue cyst in the vagina caused by retained menstrual blood seen in endometriosis.

branchial cyst

Cervical cyst.

bone cyst

A cystic mass in bone, usually a normal variant or a benign tumor.

Boyer cyst

See: Boyer cyst

cervical cyst

A closed epithelial sac derived from a branchial groove of its corresponding pharyngeal pouch. Synonym: branchial cyst

chocolate cyst

An ovarian cyst with darkly pigmented gelatinous contents.

colloid cyst

A cyst with gelatinous contents.

complex cyst

A cyst that consists of solid material and fluid-filled cavities; it may have walls of tissue inside it or internal echoes. When a complex cyst is identified on ultrasound, surgical removal is generally indicated to exclude malignancy.

congenital cyst

A cyst present at birth and resulting from abnormal development, such as a dermoid cyst, imperfect closure of a structure as in spina bifida cystica, or nonclosure of embryonic clefts, ducts, or tubules, such as cervical cysts.

daughter cyst

A cyst growing out of the walls of another cyst.

dental cyst

A cyst that forms from any of the odontogenic tissues.

dentigerous cyst

A fluid-filled, epithelial-lined cyst usually surrounding the crown of a tooth that is erupting or has not yet erupted. The tooth normally erupts through the cyst without treatment. Synonym: eruption cyst; follicular cyst; follicular odontoma

dermoid cyst

1. An ovarian teratoma.
2. A nonmalignant cystic tumor containing elements derived from the ectoderm, such as hair, teeth, or skin. These tumors occur frequently in the ovary but may develop in other organs such as the lungs.

distention cyst

A cyst formed in a natural enclosed cavity, such as a follicular cyst of the ovary.

echinococcus cyst

Hydatid cyst.

endometrial cyst

An ovarian cyst or tumor lined with endometrial tissue, usually seen in ovarian endometriosis.

epidermoid cyst

A cyst filled with keratin, sebum, and skin debris that may form on the scalp, the back of the neck, or the axilla. It is benign andf can be removed surgically. Synonym: sebaceous cyst

eruption cyst

Dentigerous cyst.

extravasation cyst

A cyst arising from hemorrhage or escape of other body fluids into tissues.

exudation cyst

A cyst caused by trapping of an exudate in a closed area.
Enlarge picture
FOLLICULAR CYST: Follicular cysts seen on ultrasonography of the thyroid gland.

follicular cyst

A cyst arising from a follicle, as a follicular cyst of the thyroid gland, the ovary, or a forming tooth. Synonym: dentigerous cyst See: illustration

ganglion cyst

ganglion (2)

Gartner cyst

See: Gartner cyst

Gorlin cyst

See: Gorlin cyst

hydatid cyst

A cyst formed by the growth of the larval form of Echinococcus granulosus, usually in the liver. Synonym: echinococcus cyst

implantation cyst

A cyst resulting from displacement of portions of the epidermis, as may occur in injuries.

intraligamentary cyst

A cystic formation between the layers of the broad ligament.

involutional cyst

A cyst occurring in the normal involution of an organ or structure, as in the mammary gland.

keratin cyst

A cyst containing keratin.

cysts of liver

Simple cysts, usually small and single; or hydatid cysts; or cysts associated with cystic disease of the liver, a rare condition usually associated with congenital cystic kidneys. See: Echinococcus granulosus; hydatid

meibomian cyst

Chalazion.

meniscus cyst

A fluid-filled cyst often associated with a degenerative horizontal meniscal tear, more frequently seen in the lateral meniscus of the knee. This ganglion-like cyst may present with a palpable mass at the joint line of the knee and can be visualized by magnetic resonance imaging.

morgagnian cyst

See: Morgagni, Giovanni B

Morgagni cyst

See: Morgagni, Giovanni B

mother cyst

A hydatid cyst enveloping smaller ones.

mucous cyst

A retention cyst composed of mucus.

nabothian cyst

A cyst caused by closure of the ducts of the nabothian glands in the uterine cervix as a result of chronic cervicitis.

odontogenic cyst

A cyst associated with the teeth, such as a dentigerous or radicular cyst.

ovarian cyst

A fluid-filled cyst that develops in the ovary and consists of one or more chambers. The main types of cysts are follicular cysts, the corpus luteum, teratoma, and endometrioma. The patient's primary complaint is generally pelvic pain or pain during intercourse. The cysts may be palpated during bimanual examination but are diagnosed by ultrasound. Many cysts resolve spontaneously. Although nonmalignant, the cyst may have to be removed surgically because of twisting of the pedicle, which causes gangrene, or because of pressure.
See: polycystic ovary syndrome

parasitic cyst

A cyst enclosing the larval form of certain parasites, such as the cysticercus or hydatid of tapeworms or the larva of certain nematodes, i.e., Trichinella.

parovarian cyst

A cyst of the parovarium.

periapical cyst

Radicular cyst.

pilar cyst

An epithelial cyst with a wall that resembles the follicular epithelium. It is filled with a homogeneous mixture of keratin and lipid.
Synonym: trichilemma cyst

pilonidal cyst

A cyst most often in the sacrococcygeal region, usually at the upper end of the intergluteal cleft. It is due to a developmental defect that permits epithelial tissue to be trapped below the skin or may be acquired. This type of cyst may become symptomatic in early adulthood when an infected draining sinus forms.
Synonym: pilonidal fistula

popliteal cyst

Baker cyst.

porencephalic cyst

An anomalous cavity of the brain that communicates with the ventricular system.

proliferative cyst

A cyst lined with epithelium that proliferates, forming projections that extend into the cavity of the cyst.

radicular cyst

A necrotic, inflammatory cyst that develops at the root of a nonvital tooth. The cyst is attached to the root of the tooth and may be lateral to it if the cyst is associated with a lateral pulp canal.
Synonym: periapical cyst; root-end cyst

retention cyst

A cyst retaining the secretion of a gland, as in a mucous or sebaceous cyst.

root-end cyst

Radicular cyst.

sebaceous cyst

Epidermoid cyst.

seminal cyst

A cyst of the epididymis, ductus deferens, or other sperm-carrying ducts that contain semen.

suprasellar cyst

A cyst of the hypophyseal stalk just above the floor of the sella turcica. Its wall is frequently calcified or ossified.

synovial cyst

Accumulation of synovia in a bursa, synovial crypt, or sac of a synovial hernia, causing a tumor.

theca-lutein cyst

Benign enlargement of the Graafian follicle, typically occurring in pregnancies (particularly in multiple pregnancies) or in other conditions that cause markedly elevated levels of serum human chorionic gonadotropin (HCG) levels, e.g., molar pregnancies or choriocarcinomas.
Synonym: hyperreactio luteinalis

trichilemma cyst

Pilar cyst.

tubo-ovarian cyst

An ovarian cyst that ruptures into the lumen of an adherent uterine tube.

unilocular cyst

A cyst containing only one cavity.

vaginal cyst

A cyst in the vagina.

vitelline cyst

A congenital cyst of the gastrointestinal canal. Lined with ciliated epithelium, it is the remains of the omphalomesenteric duct.

wolffian cyst

A cyst lying in one of the broad ligaments of the uterus.
illustration

cyst

An abnormal, usually spherical, walled cavity filled with secreted fluid or semi-solid matter derived from the cyst itself. Most cysts are benign but a few are malignant. Retention cysts may form when the outlet of normal glands become blocked. Sebaceous cysts and eyelid MEIBOMIAN CYSTS are of this type.

cyst

  1. a bladder or bag-like structure that may contain the resting stage of an organism. Many groups or organisms have encysted stages, e.g. protozoans, nematodes, flukes, tapeworms.
  2. a MORBID structure arising as an outgrowth of the skin, such as a sebaceous cyst, usually arising from a blocked duct, or an internal growth, for example, an ovarian cyst.

Cyst

A protective sac that includes either fluid or the cell of an organism. The cyst enables many organisms to survive in the environment for long periods of time without need for food or water.

cyst

abnormal sac with a membranous lining, containing fluid or semisolid material
  • dermoid cyst developmental, fibrous walled cyst lined with stratified epithelium and containing hair follicles, sweat glands and sebaceous glands

  • retention cyst cyst formation due to retention of gland secretion

  • sebaceous cyst sebaceous gland retention cyst

cyst

(sist)
An abnormal sac containing gas, fluid, or a semisolid material, with a membranous lining.
[G. kystis, bladder]

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.
Enlarge picture
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.
Enlarge picture
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.

cyst

1. a closed epithelium-lined sac or capsule containing a liquid or semi-solid substance. Most cysts are harmless but 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. See also specific locations and organs.
2. a stage in the life cycle of certain parasites, during which they are enveloped in a protective wall. See also cystic.

aneurysmal cyst
see bone cyst.
blood c's
these are found in the carcasses of poultry at meat inspection. They are small round cystic lesions containing blood. They are hemangiomas.
branchial cyst, branchiogenic cyst, branchiogenous cyst
one formed from an incompletely closed branchial cleft. See also branchial cyst.
cervical c's
retention cysts of glands in the uterine cervix in the cow, are palpable as fluctuating masses on rectal examination. Called also nabothian cyst or follicle.
chocolate cyst
one filled with hemosiderin following local hemorrhage.
cutaneous cyst
see epidermal cyst, dermoid cyst, follicular cyst, sebaceous cyst.
daughter cyst
one that develops within a parent cyst, e.g. hydatid cyst.
dentigerous cyst
see dental cyst.
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.
epidermal inclusion cyst
see epithelial inclusion.
exudation cyst
a cyst formed by the slow seepage of an exudate into a closed cavity.
fatty cyst
formed when fat accumulates in large amounts and the cells break down forming a central mass of lipid surrounded by a multinuclear rim.
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.
Gartner's duct cyst
see cystic gartner's ducts.
horn cyst
intracutaneous cystic accumulations of keratin. Seen in trichoepitheliomas and basal cell tumors. Called also keratin cyst.
hybrid cyst
one combining elements of epidermoid and trichilemmal cysts.
hydatid cyst
the larval stage (metacestode) of the tapeworms Echinococcus granulosus and E. multilocularis. See also hydatid disease.
inclusion cyst
see epidermal cyst.
interdigital c's
see pododermatitis; interdigital pyoderma.
keratin 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 and often rancid.
lateral cervical cyst
see branchial cyst.
luteal c's
develop from ovarian follicles which fail to rupture but have a lining of luteal cells. Anestrus is the presenting clinical sign.
marine fish c's
worldwide occurrence in fish of round nodules in fibrous capsules; the cause is unknown.
meibomian cyst
mesenteric cyst
congenital, thin-walled cyst between the leaves of the mesentery; may enlarge and cause colic or even intestinal obstruction.
cyst mites
see laminosioptescysticola.
cyst of Morgagni
nabothian cyst
see cervical cyst (above).
orbital cyst
ovarian cyst
see cystic ovarian disease.
parasitic cyst
one forming around larval parasites (tapeworms, amebae, trichinae) that enter the body.
pseudohorn cyst
invagination of hyperplastic epidermis; not a true cyst.
retention cyst
a tumor-like accumulation of a secretion formed when the outlet of a secreting gland is obstructed. These cysts may develop in any of the secretory glands—the mammae, pancreas, kidney, salivary or sebaceous glands, and mucous membranes. See also renal retention cysts.
sarcosporidian c's
cylindrical cysts (schizonts) containing bradyzoites, found in the muscles of those infected with Sarcocystis spp.
subconjunctival cyst, conjunctival cyst
misplaced secretory tissue which causes a slowly enlarging, fluctuant subconjunctival mass.
uveal cyst
an acquired or congenital structure which may arise from the iris or the ciliary body. Visible as a mass attached to the iris or may be floating freely in the anterior chamber. Those arising from the ciliary body may not be visible. Seen most commonly in horses. See also iris cyst.
vitelline cyst
a congenital cyst lined with ciliated epithelium occurring along the gastrointestinal canal; the remains of the omphalomesenteric duct.

Patient discussion about cyst

Q. What is ovarian cyst and why is it painful? Is that pathological? Dangerous? Need information please.

A. don’t worry- ovarian cyst is usually a natural thin. It shouldn’t be of a problem. And if you need to hear it from a gynecologist:
http://www.5min.com/Video/Menstrual-Pains-and-Cysts-2374793

Q. What is the treatment for an arachnoid cyst? My 15 year old son has just been diagnosed with an arachnoid cyst. What is the treatment? Is an operation necessary?

A. An operation is not always necessary, it depends on the size and location of the cyst. I suggest you take your son to a neurologist or a neurosurgeon for further consult.

Q. What is pilonidal cyst?

A. very true, here is another site that may help you too:
http://www.mayoclinic.com/print/pilonidal-cyst/DS00747/DSECTION=all&METHOD=print

More discussions about cyst