Dermoid cyst

Main article: TeratomaA dermoid cyst is a cystic teratoma that contains an

A small (4 cm) dermoid cyst of an ovary, discovered during aC-section

array of developmentally mature, solid tissues. It fre-quently consists of skin, complete with hair follicles, andsweat glands. Other commonly found components in-clude: clumps of long hair, pockets of sebum, blood, fat,bone, nails, teeth, eyes, cartilage, and thyroid tissue.Because it grows slowly and containsmature tissue, a der-moid cyst is almost always benign. The rare malignantdermoid cyst usually develops squamous cell carcinomain adults; in infants and children it usually develops anendodermal sinus tumor.[1]:781

1 LocationA dermoid cyst can occur wherever a teratoma can occur,since they are categorically classied as such.

1.1 Ovarian dermoid cystsOvaries normally grow cyst-like structures called follicleseach month. Once an egg is released from its follicle dur-ing ovulation, follicles typically deate. Sometimes uidaccumulates inside the follicle, forming a simple (con-taining only uid) cyst.[2] Themajority of these functionalcysts resolve spontaneously.While all ovarian cysts can range in size from very small toquite large, dermoid cysts are not classied as functional

Large ovarian cyst

Dermoid cyst in vaginal ultrasonography.

cysts. Dermoid cysts originate from totipotential germcells (which are present at birth) that dierentiate abnor-mally, developing characteristics of mature dermal cells.Complications exist, such as torsion (twisting), rupture,and infection, although their incidence is rare. Dermoidovarian cysts which are larger or present complicationsmight require removal by either laparoscopy or laparo-tomy (traditional surgery).[3][4]

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1.2 Periorbital dermoid cysts

Dermoid cysts can appear in young children, often nearthe lateral aspect of the eyebrow (right part of the righteyebrow or left part of the left eyebrow). These are some-times excised and sometimes simply kept under observa-tion, depending on the perceived amount of risk.An inammatory reaction can occur if the dermoid cyst isdisrupted, and dermoid cysts can recur if not completelyexcised. Sometimes complete excision is not practical ifthe cyst is in a dumbbell conguration where it extendsthrough a suture line in the skull.If the dermoid cysts appear on the medial aspect, the pos-sibility of an encephalocele becomes greater and shouldbe considered among the dierential diagnosis.

1.3 Spinal dermoid cysts

Spinal dermoid cysts are benign ectopic growths thoughtto be a consequence of embryology errors during neuraltube closure. Their reported incidence is extremely rare,accounting for less than 1% of intramedullary spinal cordtumours. It has been proposed that a possible 180 casesof spinal dermoid tumours have been identied over thepast century in the literature.[5][6]

Dermoid cysts more often involve the lumbosacral regionthan the thoracic vertebrae and are extramedullary pre-senting in the rst decade of life.Various hypotheses have been advanced to explain thepathogenesis of spinal dermoids, the origin of which maybe acquired or congenital.

Acquired or iatrogenic dermoids may arise fromthe implantation of epidermal tissue into the sub-dural space i.e. spinal cutaneous inclusion, dur-ing needle puncture (e.g. lumbar puncture) or dur-ing surgical procedures on closure of a dysraphicmalformation.[6][7]

Congenital dermoids, however, are thought to arisefrom cells whose position is correct but which failto dierentiate into the correct cell-type. The long-time held belief was that the inclusion of cutaneousectodermal cells occurred early in embryonic life,and the displaced pluripotent cells developed into adermoid lesion.[7][8]

Spinal abnormalities, e.g. intramedullary dermoid cystsmay arise more frequently in the lumbosacral region(quite often at the level of the conus medullaris) and maybe seen with other congenital anomalies of the spine in-cluding posterior spina bida occulta as identied by theneuroradiological analysis.[5][8]

2 TreatmentTreatment for dermoid cyst is complete surgical removal,preferably in one piece and without any spillage of cystcontents. Marsupialization, a surgical technique oftenused to treat pilonidal cyst, is inappropriate for dermoidcyst due to the risk of malignancy.The association of dermoid cysts with pregnancy has beenincreasingly reported. They usually present the dilemmaof weighing the risks of surgery and anesthesia versus therisks of untreated adnexal mass. Most references statethat it is more feasible to treat bilateral dermoid cystsof the ovaries discovered during pregnancy if they growbeyond 6 cm in diameter. This is usually performedthrough laparotomy or very carefully through laparoscopyand should preferably be done in the second trimester.[9]

3 Dierential diagnosisA small dermoid cyst on the coccyx can be dicult todistinguish from a pilonidal cyst. This is partly becauseboth can be full of hair. A pilonidal cyst is a pilonidalsinus that is obstructed. Any teratoma near the body sur-face may develop a sinus or a stula, or even a clusterof these. Such is the case of Canadian Football Leaguelinebacker Tyrone Jones, whose teratoma was discoveredwhen he blew a tooth out of his nose.[10]

4 See also Ovarian cyst Cyst Dermoid sinus, more commonly known as apilonidal cyst

Proliferating trichilemmal cyst List of cutaneous conditions

5 References[1] Freedberg, et al. (2003). Fitzpatricks Dermatology in

General Medicine. (6th ed.). McGraw-Hill. ISBN 0-07-138076-0.

[2] Mayo Clinic: Ovarian Cysts https://www.mayoclinic.com/health/ovarian-cysts/DS00129/DSECTION=causes

[3] Cyst Managementhttp://onlinelibrary.wiley.com/doi/10.1002/uog.7610/full#bib2

[4] Dermoid Cyst of the Ovary Dened http://www.medterms.com/script/main/art.asp?articlekey=2960

3[5] Najjar et al (2005) Dorsal Intramedullary Dermoids. Neu-rosurgery Review. 28:320-325

[6] Aalst et al (2009) Intraspinal Dermoid and EpidermoidTumours: Reports of 18 Cases ad Reapproasal of the Lit-erature. Pediatric Neurosurgery. 45:281-290

[7] Roth et al (1966) Intramedullary dermoid - Journal ofneurology, Neurosurgery and Psychiatry 29:262-264

[8] Muraszko et al (2000) Intramedullary spinal tumours ofdisordered embryogensis Journal of Neuro-oncology47:271-281

[9] Walid MS, Boddy MG. (2008). Bilateral dermoid cystsof the ovary in a pregnant woman: case report and reviewof the literature. ArchGynecol Obstet. 279 (2): 105108.doi:10.1007/s00404-008-0695-3. PMID 18509663.

[10] Maki: Jones returns to say goodbye Globe and Mail,November 16, 2006

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Dermoid cyst Source: http://en.wikipedia.org/wiki/Dermoid%20cyst?oldid=633798106 Contributors: Mirv, Nunh-huh, Zigger, JasonQuinn, R, Discospinster, Leigh Honeywell, Arcadian, Hooperbloob, Anthony Appleyard, PatrickFisher, Wouterstomp, Axl, Seans PotatoBusiness, Wtmitchell, Kenyon, Ekem, BD2412, Pigman, Thane, AndrewWTaylor, George Church, TheLimbicOne, Joelmills, Patho, Cy-debot, Ebyabe, Magnumone, Noclevername, EyeMD, Hydro, Epeeeche, ChristinaDunigan, JaGa, WLU, Threedots dead, Nono64, Al-phaEta, Mikael Hggstrm,MyCore Competency is Competency, Una Smith, Monty845, Jantaro, Doc United States, Atlas87, Bobjgalindo,Rhcastilhos, Schomynv, Farolif, ChorleyBoy, BOTarate, DragonFury, Addbot, DOI bot, 15lsoucy, Diptanshu.D, MrOllie, Luckas-bot,Yobot, AnakngAraw, Bluerasberry, Materialscientist, Citation bot, Xqbot, Taylornate, Citation bot 1, Pinethicket, Nishantkumarnishu,Sysiphuslove, Rsk2010, Netha Hussain, Sazaja, ClueBot NG, Chester Markel, Helpful Pixie Bot, Aichd13, Veritas Lev, MrBill3, FitzJD,Mypageone, Intelxe0n, Dough34, Sandylwilson and Anonymous: 48

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Own work Original artist: Mikael Hggstrm. File:Large_ovarian_cyst.JPG Source: http://upload.wikimedia.org/wikipedia/commons/0/09/Large_ovarian_cyst.JPG License: CC-

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LocationOvarian dermoid cystsPeriorbital dermoid cystsSpinal dermoid cysts

TreatmentDifferential diagnosisSee also ReferencesText and image sources, contributors, and licensesTextImagesContent license