Odontogenic Cysts And Tumors (2).ppt

7/16/2019 Odontogenic Cysts And Tumors (2).ppt

http://slidepdf.com/reader/full/odontogenic-cysts-and-tumors-2ppt 1/273

Odontogenic Cysts

And Tumors



Cyst: it’s a pathological cavity lined by epithelium & filledwith fluid or semi fluid material.

In the jaw bones & oral tissue there are remnant of epith.come mostly from odontogenic apparatus & most of theseremnants are embryonic in origin .for this reason the jaw

bone are affected by a large numbers of cysts incomparism to other bones in the body.

The epith. remnants that give rise to these cysts are:1- rest of malasses (e.g. P.A.C & residual cyst)2- reduced enamel epithelium (dentigerous cysts & eruption cyst)3- remnants of the dental lamina (rest of serres) (e.g.odontogenic keratocyst, lateral periodontal cyst, gingival

cyst & glandular odontogenic cyst).



What is a cyst?

An abnormal space withintissue lined by epithelium



Classification of the jaw cysts

I-Epithelial cysts A- odontogenic: 1- developmental cyst (odontogenic keratocyst, dentigerous cyst, eruption

cyst, lateral periodontal cyst, gingival cyst, glandular cyst) 2- inflammatory cyst (radicular cyst, paradental cyst)

B- non-odontogenic:

Nasopalatine duct cyst, nasolabial cyst

II-Non epith. (primary bone cysts) Solitary bone cyst (traumatic, simple), aneurysmal bone cyst, Stafine cyst

III-Soft tissue cysts: Salivary mucoceles (mucus extravasation, mucus retention) Dermoid & epidermoid cyst Lymphoepithelial cyst Thyroglossal tract cyst



Odontogenic cysts

A cyst in which the lining of the lumen is derivedfrom epithelium produced during tooth development,these include:

1- cysts derived from rests of Malassez: Periapical

cyst (radicular)

2- cysts derived from reduced enamel epithelium: reduced enamel epithelium refers to the layer of epith. Thatremains around the tooth’s crown after enamel formation iscomplete. This layer of epith. Is derived from thespecialized epith. Components of the enamel organ (innerenamel epith., stratum intermedium, stellate reticulum, & outer enamel epith.)That were active during amelogenesis,& collapse into a thinned dormant membrane of two orthree cells in thickness.



Odontogenic Cysts• Inflammatory – Periapical (radicular) cyst – Residual periapical (radicular)

cyst – Buccal bifurcation cyst (usually

firstmolars)• Paradental cysts (partially

eruptedthird molars



Radicular (Periapical) Cyst

!Most common (65%)

!Epithelial cell rests of Malassez

!Response to inflammation!Radiographic findings

!Pulpless, nonvital tooth

!Small well-defined periapical radiolucency!Histology

!Treatment - extraction, root canal



Radicular Cyst



Periapical Cyst vs.Periapical Granuloma

• CANNOT TELL THE

DIFFERENCE BY

X-RAY• CAN ONLY TELL BY

HISTOLOGY

Periapical Granuloma

Granulation Tissue - Noepithelial lining

Periapical CystTrue cyst with centrallumen and epitheliallining



Why does a periapical cystform instead of just a

granuloma? Simply the chance of Rests

of Malassez being in thearea of inflammation



Periapical Inflammation

Odontogenic Epithelial Rest

1. Cells in the rest proliferate due to the inflammation

2. The ball of cells gets so big the center gets too far fromthe blood supply, the cells in the center die



3. The center of the ball of cells then has a higher proteinconcentration than the surrounding tissue

4. Fluid flows into the center by osmotic pressure, cyst

expands, more cells grow around the periphery, morecells in the center die, concentration increases again

5. Osmotic pressure can keep expanding the cystindependent of the inflammation



Result = Periapical Cyst



A radiolucency in the jaws must beinvestigatedIf the teeth in the area are

vital, you must biopsy theradiolucent area.If non-vital, obviously RCT



Vitality Test!Vitality Test!

Vitality Test!Vitality Test!

Vitality Test!



Residual Cyst



Paradental Cyst

! Associated with partially impacted 3rd

molars

!Result of inflammation of the gingivaover an erupting molar

!0.5 to 4% of cysts

!Radiology - radiolucency in apicalportion of the root

!Treatment - enucleation



Paradental Cyst



Odontogenic Cysts

! Inflammatory ! Developmental

! Radicular ! Dentigerous

! Paradental ! Developmental

lateral periodontal ! Odontogenic

keratocyst

! Glandular

odontogenic



Odontogenic Cysts• Developmental

– Dentigerous cyst – Odontogenic keratocyst – Orthokeratinized odontogenic cyst

– Gingival (alveolar) cyst of thenewborn

– Gingival cyst of the adult – Lateral periodontal cyst – Calcifying odontogenic (Gorlin) cyst – Glandular odontogenic cyst – Eruption cyst

Cyst Lumen

LiningEpithelium



A- Dentigerous cyst : an odontogenic cyst that surrounds the

crown of an impacted tooth,

caused by fluid accumulation

between the reduced enamel epith.& the enamel surface, resulting

in a cyst in which the crown is located

within the lumen & root outside.

The pathogenesis of this cyst is

uncertain but apparently it developsby accumulation of fluid between the

REE & the tooth crown. Progressivegrowth of the cyst leads to dilatationof the dental follicle.



Clinically:

These cysts are commonly associated with unerupted mand. or max. thirdmolars or max. canine.

The cyst usually remains asymptomatic but may produce some swelling or pain, particularly if it is large or inflamed.

Radiographically:

Mostly diagnosed by their radiographic appearance. They present as wellcircumscribed radiolucency surrounding the crown of a tooth.



Dentigerous Cyst



•Dentigerous – “tooth containing” cyst

•Origin – reduced enamel epithelium

(dentalfollicle)

If a radiolucency is

ASSOCIATEDwith an unerupted tooth

Dentigerous cyst should beyour FIRST differential

diagnosis

Differential Diagnosis• Dentigerous Cyst• Odontogenic Keratocyst• Ameloblastoma



•Like other cysts, uncomplicated DC(small DC) causes no symptoms untilswelling becomes noticeable & is

discovered on a routine radiographicexamination or when the cause issought for a missing tooth.•Large cyst may be associated with a

painless expansion of the bone in theinvolved area, infection of a DC causesthe usual symptoms of pain andaccelerated swelling, such infection mayarise in a DC that is associated with apartially erupted tooth or by extensionfrom a periapical or periodontal lesionthat affects an adjacent tooth.

Radiographically:



Radiographically:

It appears as well circumscribed radiolucuncies surroundingthe crown of an unerupted tooth which may displace fromits normal position.

If the width of RL around the crown is less than + 2mm, itis considered fitting a normal tooth follicle, and if the RLspace is of least 3 to 4 mm then a DC should beconsidered. The RL usually has well-defined and oftensclerotic borders.

A large DC may appear radiographically as a multilocularprocess because of the persistence of bone trabecularewithin the RL.

However, a keratocyst or ameloblastoma may occasionally

envelop the crown of the tooth and appear radiographicallysimilar to DC. The diagnosis ultimately therefore dependson histological examination that’s why radiographicalfindings are not diagnosis for a DC.



Histopathology:



op o ogy

The gross examination of the wall of DC show nodular thickening,which must examined microscopically to role out early neoplasticchanges.

The lining of a non-inflammated DC composed of stratifiedsequamous epithelium, rarely showing keratinization.

Mucous - producing cells are sometime seen in the epithelium.

The wall consists of loose fibrous C.T. with inactive odontogenic

epithelial rests. Small nests of sebaceous cells rarely may benoticed with the fibrous cyst wall. These mucous and sebaceouselements are believed to represent the multipotentiality of theodontogenic epithelial lining in a DC. Therefore it's advisable toexamined DC microscopically and to role out the presenceof early neoplastic changes such as mucoepidermoid Ca,ameloblastoma and sequamous cell Ca.

In inflammed DC The fibrous wall is more collagenized with the chronic

inflammatory cells, and the lining show hyperplasia and developrete -ridges.



Histopathology:

The epith. Lining is relatively uniform layer of non-keratinized, stratified, squamous epith., measuring 2-10 cellsin thickness.

This lining may alters by inflammation & may becomehyperplastic, atrophic, or ulcerated.

Variable numbers of mucus cells are occasionally seen in theepith. Lining .

Like the periapical cyst, crystalline cholesterol deposits,hemosiderin deposits, hyaline (Rushton ) bodies, & lipid ladenmacrophage are also seen in dentigerous cyst.

Long standing cyst will occasionally exhibit areas of keratinization or premalignant (dysplastic) changes of their epith. Lining.

Treatment: either by enucleation or marsupilization,recurrency is uncommon



Dentigerous Cyst

Treatment



Treatment

Surgical enucleation, with removal of

associated tooth. A large DC may betreated by marsupialization, which permitsdecompression of the cyst and reductionin the size of bone defect, especially incanines, and then we do alignment of thetooth properly by orthodontic appliance.Recurrences are very rare.

However, several potential complicationsmust be considered when recurrenceoccurs. In which it will need more

aggressive treatment.



B- Eruption cyst: Is a variant of the dentigerous cyst that develops in

the alveolar soft tissue around the crown of an erupting tooth.

Clinically, appear as fluctuant swelling of the

alveolar ridge, the lesion may bleed during

mastication giving rise to the term “eruption

hematoma” Histologically, same as those of a dentigerous cyst.

Most of these cysts require no treatment because

rupture spontaneously during mastication. But

sometime surgical exposure of the crown of affected

tooth may be needed.

Eruption cyst: (eruption



Eruption cyst: (eruptionhematoma)

An eruption cyst occasionally formsover a tooth about to erupt. It’s asoft tissue analogue of the DC,

results from separation of the dentalfollicle from around the crown of eruption tooth.

Presumably, the cysts developedbecause of collagen deposition in thegingival C.T. that resulted in a

thicker per coronal roof.



Clinical features



Clinical features

EC effect children and adult chiefly in thedeciduous teeth or permanent molars. Its

soft, fluctuant, translucent swelling in thegingival mucosa overlying the crown of unerupting tooth and rarely painful.

Surface trauma may result in aconsiderable amount of blood in the cysticfluid which gives its blue to purple-browncolor and that why some time referred aseruption hematomas.

No X-ray findings appear because itoccurs in soft tissue.

Histopathologically



Histopathologically

Surface oral epithelium covering theunderlying lamina propria withinflammatory cells, and the deep of the bottom is the roof of the cyst,

thin layer of non-keratinized sq.epithelium.

Treatment



Treatment

Treatment may not be neededbecause the cyst usually rupturesspontaneously permitting the toothto erupt.

Sometime simple excision of the roof of the cyst is needed to permits theeruption of tooth.

Developmental Lateral



Developmental LateralPeriodontal Cyst

!From epithelial rests in periodontal ligament

! Mandibular premolar

region ! Middle-aged men! Radiographic findings

! Interradicular radiolucency, well-defined margins

! Histology

! Nonkeratinizing stratified squamous or cuboidalepithelium

! Treatment - enucleation, curettage withpreservation of adjacent teeth

Lateral periodontal C



Lateral periodontal C

These are uncommon type of developmental OC that typicallyoccur along the root surface of atooth, it arise from rests of dental

lamina. Its asymptomatic lesion,mainly occur in mandibular canine-premolar region & less between

maxillary lateral and canine.



Radio- graphically

Appear as a well-circumscribed RL area located

laterally to the root(s) of vital tooth.

Occasionally this cyst appears as multilocular(poly cystic) and termed: botryoid OC. Theradiographic picture of lateral periodontal cyst is

not diagnostic:

An odontogenic KC that develop between theroots of adjacent teeth may show identicalradiographic findings

An inflammatory RC that occurs laterally to aroot in relation to an accessory foramen

A cyst that arises from periodontal inflammation.

Developmental Lateral



Developmental LateralPeriodontal Cyst



Derived from remnantsof the dental lamina

Lateral Periodontal Cyst

Histopathology



p gy

The typical picture is thin lining of non-keratinized epith. Which only 1-2 cell layers thick,with foci of glycogen-rich clear cells, some cyst

exhibit focal epithelial thickening (plaque) of clearcells.

Clear cell epithelial rests sometimes are seenwithin the fibrous wall.



Treatment

Conservative enuncleation, norecurrence and avoid damages toadjacent teeth.

3 cysts derived from dental lamina:



3- cysts derived from dental lamina:

A- Odontogenic Keratocyst ( okc): A cyst derived from remnants of the

dental lamina. It’s less common than the dentigerous cyst but more serous

because epith. Lining show high rate of growth.

Clinically:

Occurs in young patient, however, it can occur at any age.

The mand. Is affected more commonly than max. in the mand.,the cyst occur mostly in the 3rd molar area, while in the max.,

the 3rd molar & canine areas are usually affected. The cyst is slowly growing & asymptomatic, but later it may

cause bone expansion.

Although okc is usually present as a single lesion, it can

occasionally occur as multiple cysts that sometimes occupy allfour quadrants of the jaws as in nevoid basal cell carcinoma.



Odontogenic Keratocyst

!11% of jaw cysts

!May mimic any of the other cysts!Most often in mandibular ramus and

angle!Radiographically

!Well-marginated, radiolucency

!Pericoronal, inter-radicular, or pericoronal!Multilocular

Odontogenic keratocyst



It has specific histopathological features andclinical behavior. It arises from cell rests of thedental lamina. It shows a different growthmechanisms and biological behavior from themore common dentigerous cyst and radicularcyst, which enlarged as a result of increasedosmatic pressure within the lumen of thecyst. While the growth of the keratocyst may be

related to unknown factors inherent in theepithelium itself or enzymatic activity in thefibrous wall. That’s why now day severalinvestigators suggested that OKC beregarded as benign cystic neoplasms ratherthan cysts, and the latest WHO classification of odontogenic tumors, these lesions have given thename (keratocystic odontogenic tumors).

It makes up 3% to 11% of all odontogeniccysts.

Clinical features



The peak incidence between ages 20 to 30 years, themandible is usually affected, usually in the region of the jaw angle and the ascending remaus. KC like other jawcyst, are symptom less until the bone is expanded or they

become infected.

It grows in anterioposterior direction within mandibularycavity of the bone without causing obvious bone expansion.This is useful to differentiate clinically and radiographicallybetween DC & RC which produce bone expansion.

Multiple OK is seen in Nevoid basal cell carcinoma (Gorlinsyndrome).

When multiple KC are found in the jaws, basal cell nervous

syndrome appear to be involved in about half of cases.

This syndrome is characterized by multiple KC, basal cellnevi of the skin and bifid ribs.

Radiographically



Well defined RL area will smooth corticatedmargin. Large lesion in posterior body and

ascending remaus of the mandible may appearmultilocular. An unerupted tooth is involved inthe lesion in 25% to 40% of cases.

Differential diagnosis.

DC (radiographic findings an highly suggestivebut not diagnostic)

Large RC & residual C which are near impacted

tooth. Lateral periodontal cyst or globulomaxillary cyst if

the KC is small and between teeth.




Odontogenic 2005 Classification by the



OdontogenicKeratocystBecause of its behavior,many oral pathologistsnow consider the OKC

an odontogenic tumorthat has a cystic form

2005 Classification by theW.H.O.KeratinocysticOdontogenic Tumor

Odontogenic Keratocyst(Keratinocystic Odontogenic

Tumor)Three important thingsassociated withthis diagnosis:1. High recurrence rate (up to60%)

2. Highly aggressive (nowconsidered byW.H.O. to be an odontogenictumor)3. Relation to Gorlin syndrome

OdontogenicKeratocyst• Can be in the location of any odontogenic cyst• Can be isolated in the

jaws



Histopathology: the microscopic appearance of okc is

pathognomonic, characterized by:

Thin uniform lining of parakeratin sq. epith. 6-10 cellsthickness.

palisaded layer of columnar or cuboidal basal cells. Corrugated layer of parakeratin. Lack of rete ridges, and focal separation of epithelium C.T.

wall. The C.T wall is often loose and fibrillar and free of

inflammation. dental lamina rests and microcysts (daughter or satellite)

cyst may present in the capsule wall the capsule wall is folded

The lumen contains desquamated parakeratin.



OdontogenicKeratocystDiagnosis entirely dependson the histology of thecyst lining

1. Uniform (5-8 cells) thickness

2. Hyperchromatic, cuboidal orcolumnar basal cell layer

3. Corrugated parakeratin layer

4. Virtually no inflammation in

cyst wall



“Daughter” Cyst




!Histology

!Thin epithelial lining with underlyingconnective tissue (collagen and epithelial

nests)!Secondary inflammation may mask features

!High frequency of recurrence (up to 62%)

!Complete removal difficult and satellitecysts can be left behind



Nevoid Basal CellC i



Carcinoma(Gorlin) Syndrome• Multiple basal cell carcinomas• Multiple jaw cysts (odontogenic keratocysts)

• Numerous bone abnormalities including bifidribs, intracranial calcification, vertebralanomalies• Mild ocular hypertelorism• Epidermal cysts of the skin• Etc. Gorlin (Nevoid Basal Cell Carcinoma) Syndrome

Basal cell carcinomas in non-sun exposed areas



Multiple OKCs



Treatment of OKC

! Depends on extent of lesion ! Small

- simple enucleation, complete removal

of cyst wall

! Larger - enucleation with/without peripheralostectomy

! promote complete resection with 1 cm bony

margins (if extension through cortex, overlyingsoft tissues excised) ! Long term follow-up

required (5-10 years)



The causes of recurrence are:

Loose attachment between the epith. & C.T.

Presence of daughter cysts

Orthokeratinized OC



It's an OC that shows microscopically anorthokeratinized epithelial lining. Althoughsuch lesion were originally called theorthokeratinized variant of OK . Itrepresents 7% to 17% of all keratinizing

jaw cyst. It appear clinically and radio

graphically like dentigerous cyst, theymostly involve unerupted mandibular 3rdmolar, occur predominantly in young adultand show 2:1 male to female ratio, morecommon in the mandible than the maxilla.

They have the same clinical andradiographical features of inflammatory ordevelopmental OC it appear as aunilocular RL but occasionally it mayappear as multilocular.



Histopathology

The cyst lining is composed of st.sq.epith., whichshows an orthokeratotic surface of variousthicknesses. The epithelial lining may berelatively thin and the prominent palisaded basalcell layers of OKC are not present.

Treatment

Enucleation with curettage, no recurrence butmay be associated with greater risk of malignant

transformation.

Orthokeratinised keratocyst.P f ti f d th



Perforation of and pressure on thecyst roof has caused keratin toextrude and has helped to confirmthe diagnosis.



B- glandular odontog enic cys t :



an unusual large unilocular or multilocular odontogenic cyst, first described in

1987.

it originated from epith. Of the dental lamina & it has greater growth potential

Radiographically:

Appear as well defined, unilocular, or multilocular radiolucencies, mostly in the mandible.

Histopathology:

It’s composed of a thin squamous epith. lining that may showareas of focal epith. thickening.

The epith. Contain glandular structures or microcysts lined bycolumnar or cuboidal cells.

Treatment:

By surgical enucleation.



Glandular odontogenic cyst

It is a rare type of developmental OCthat show aggressive behavior, andit closely resemble polycystic variantof lateral periodontal cyst but has

much greater growth potential andtendency to recur.

Clinical feature



It occurs most commonly in middle agedadult, more in mandible and in anteriorregion of the jaws. Their size varies fromsmall lesion less than 1cm to largedestructive lesions that involve most of the jaw

Radiographically:

May appear as well defined unilocualr or

multilocuallr RL.



Glandular Odontogenic Cyst

Histopathology



Lining by sq.epi of varying thickness.

The interface between the epith andthe fibrous C.T. wall in generally flat.

The fibrous wall is usually devoid of any inflammatory cell infiltrate.

Small glandular structures of microcysts within epith.

glandular structure lined by cuboidalcells, the lumen contain secretoryproducts



Glandular Odontogenic Cyst

! Histology

! Stratified epithelium

! Cuboidal, ciliated

surface lining cells !

Polycystic with

secretory and

epithelial elements



GlandularOdontogenic Cyst



Treatment of GOC

!Considerable recurrence potential !25%

after enucleation or curettage !Marginal

resection suggested for larger lesions or

involvement of posteriormaxilla ! close

follow-up

Gingival cyst of newborn (alveolar)



They are small, superficial, keratin-filled cyststhat are found on the alveolar mucosa of infants.These cysts are arises from remnants of thedental lamina.

It is appear as small, usually multiple whitishpapules on the mucosa overlying the alveolar

processes of neonates.

Histopathology: show thin, flattened epith,lining with parakeratin. The lumen containkeratinaeous debris.

Treatment: not indicated, lesion rupturespontaneously.



2 Week femalebrought to pediatricdentistry clinic -parents were veryupset

Gingival cysts of the newborn

No treatmentneeded - they’llregress in a shorttime

Gingival cyst of the adult



It considered the extra osseous form of thelateral periodontal cyst. Its uncommon lesion, itoccurs mostly in mandibular canine and premolararea 60-75% and is most commonly found inpatients in the 5th and sixth decades of life.

They are almost located on the facial gingival or

alveolar mucosa. It appears as small painlessswelling bluish-gray in color.

Histopathologic: resemble lateral periodontalcyst.

Treatment: conservative surgical enucleation.



Gingival Cyst of the Adult



Lining derivedfrom remnantsof the dentallamina

Gingival cyst

Malignant lymphoma

Calcifying OC: (calcifying chost cell OC)Gorlin cyst Its ncommon lesion that sho di e s



Its uncommon lesion, that show divershistopathological feature and variable clinicalbehavior. Although it is widely considered to

regards a cyst, some investigators prefer toclassify it as a neoplasm. Recent WHO classification of OT groups, consider

the calcifying OC with all its variants as an OTrather than an OC.

Clinical features COC Is predominantly an intraosscous and 13-

30% of cases reported as per- peripheral (extraosseous) lesion.

Usually occur in maxilla region, the mean age is33years. Those which associated with odontomatend to occur in younger patients.



Radiographically: RL andmultilocualr RL

RO structures are present in about

one third to one half of cases.



Calcifying

Odontogenic(Gorlin) Cyst

Histopathology

The cyst lining consist of epithelium often with palisading of



The cyst lining consist of epithelium often with palisading of the basal cells which may resemble ameloblasts , theoverlying layer of loosely arranged epithelium mayresemble stellate reticulum.

The most striking features is areas of abnormalkeratinization producing swollen cells whose outlines andnuclei become progressively polar (ghost cell)

The nature of the ghost cell is controversial, some believethat this change represent 1-coagulative necrosis oraccumulation of enamel protein.

It is a form of normal or aberrant keratinization of Oralepithelium.

Masses of ghost cells may fuss to form large sheets of amorphous a cellular materials.

Calcification within the ghost cells is common.

Treatment: surgical enucleation and prognosis good.



“Ghost”

cellscalcify



Squamous cell carcinoma arising in theepithelial lining of a cyst

A rare, but definite possibility in any cyst

Odontogenic tumors: According to the origin of these tumors, they are classified

as follows:



Tumor of odontogenic epithelium (ectodermal origin).• Ameloblastoma

Malignant ameloblastoma

Ameloblastic carcinoma• Clear cell odontogenic carcinoma• Adenomatoid OT• Calcifying epithelial OT• Squamous OT

odontogenic ectomesenchymal with hard tooth (mixed OT)• Ameloblastic fibroma• Ameloblastic fibro-odontoma• Ameloblastic fibrosarcoma• Odonto ameloblastoma• Compound odontoma• Complex odontoma

tumors of odontogenic ectomesenchymal alone• Odontogenic fibroma• Myxoma• Cementoblastoma• Granular cell odontogenic fibroma

Biologic Classification of Odontogenic Tumors*



Odontogenic Tumors

BENIGN, NO RECURRENCE POTENTIAL Adenomatoid odontogenic tumor Squamous odontogenic tumor

Cementoblastoma Periapical cementoosseous dysplasia Odontoma

BENIGN, AGGRESSIVE Ameloblastoma Clear cell odontogenic tumor (some consider this a carcinoma) Odontogenic ghost cell tumor (COC, solid type) Odontogenic myxoma Odontoameloblastoma

MALIGNANT Malignant ameloblastoma Ameloblastic carcinoma Primary intraosseous carcinoma Odontogenic ghost cell carcinoma Ameloblastic fibrosarcoma

BENIGN, SOME RECURRENCE POTENTIAL

Cystic ameloblastoma (unicystic) Calcifying epithelial odontogenic tumor Central odontogenic fibroma Florid cementoosseous dysplasia Ameloblastic fibroma and fibroodontoma *From Regezi, et al.

A l bl t



Ameloblastoma

!Most common odontogenic tumor

!Benign, but locally invasive

!Clinically and histologically similar to BCCa

!4th and 5th decades

!Occasionally arise from dentigerous cysts

!Subtypes - multicystic (86%), unicystic(13%), and peripheral (extraosseous - 1%)



Are the most common neoplasms of the jaws.



They may arise from

Rest of dental lamina

Developing enamel organ Epithelial lining of OC

The basal cell of the oral mucosa

ameloblastoma are slow-growing, locally

invasive, produce bone expansion and facialdeformity, had high recurrence rate, nometastasis, it present in 3 type.

(They occur in 3 different clinico-radiographicsituations which deserve separate consideration

because of different therapeutic considerationsand prognosis)

A l bl t



Ameloblastoma

!Radiographic findings

!Classic - multilocular radiolucency of posterior mandible

!Well-circumscribed, soap-bubble!Unilocular - often confused with

odontogenic cysts

!Root resorption - associated withmalignancy

A l bl t



Ameloblastoma



1-common polycystic ameloblastoma

(C ti l lid lti ti i t



(Conventional solid or multicystic interoasseousameloblastoma)

It's most common type, occur in patients over25y (20-40y) it is rare in children, there is no sexpredilection.

About 80%-85% of conventional ameloblastomaoccur in the mandible and ascending rams.

The tumor is often asymptomatic, a small lesionare detected during a radiographic examination.If untreated the lesion grow slowly to massiveproducing facial deformity when palpatedproduce easily bone cracks due to thin outer shellof expand bone (egg shell cracking, diagnosticsign).

Histopathology: several microscopic subtypes of conventi

onal ameloblastoma are recognized:

Th l i l f t i th l bl t lik ll hi h



The classical feature is the ameloblast- like cells which arepalisaded columnar basal cells, with reverse polarization(nucleous away from basement membrane). It may be

arranged in the following forms:

Follicular: It is the most common and resembles early stage of tooth

development. It consisted of island of odontogenicepithelium resemble enamel organ in a mature fibrous C.T.

stroma. These islauds consist of outer border of palisadedameloblast-like cell and a central loosely arranged angularcells resembling the stellate reticulum.

The central area may undergo degeneration and formmicrocystic changes or some tissue they transformed to

sq. cells and produce keratin and referred asAcanthomatous pattern. If these cells are swollen anddensely packed with eonsinophilic granules, it referred asgranular cell, variant.



Large epithelial areas of loosely structured spindle epitheliumenclosing liquefacting stromal areas are typical of a plexiformameloblastoma. The epithelial cells facing the stroma showpalisading



p g

Ameloblastoma



Ameloblastoma



In cases of follicular ameloblastoma, the tumour consistsof epithelial islands with a loose oedematous centre and aperipheralrim of palisading cells Liquefaction of their centre results



rim of palisading cells. Liquefaction of their centre resultsin cyst formation

2- Plexiform pattern: It consist of anastomosing cords or large sheets of odontogenic

epithelium in a lossely arranged and vascular supportingstroma.



3- Acanthamatous pattern 4- Granular cell pattern: Represent aging or degenerative change in long standing lesion

, seen in young patient and in clinically aggressive tumors. 5- Desmoplastic pattern Contain small islands and cord of odontogenic epithelium in a

densely collagenized stroma. IHC studies have shown increased production of the cytokeratin

which know as transforming growth factor-B (TGF-B) inassociation with this lesion which may be responsible fordesmoplasia.

6- Basal cell pattern It is the least common type , composed of nests of uniform

basaloid cells which histologically are very similar to basal cellcarcinoma of the skin , no stellate reticulum is present.

Desmoplastic ameloblastoma consists of denselypacked spindle cells lying in a fibrous stroma. Palisading of peripheralcells is not a conspicuous feature in this type of ameloblastoma



Treatment of Ameloblastoma



! According to growth characteristics and type! Unicystic! Complete removal

! Peripheral ostectomies if extension through cystwall

! Classic infiltrative (aggressive)

! Mandibular - adequate normal bone aroundmargins of resection

!

Maxillary - more aggressive surgery, 1.5 cmmargins

! Ameloblastic carcinoma

! Radical surgical resection (like SCCa)!



Treatment: It never depends on

histopathological pattern, all types

are locally invasive thereforeresistant.extensive surgical removal( block resection ) is recommended .

The lesion is radio resistant.

Unicystic amelblastoma



It is a new entity: it account for 10% to

46% of all intraosseous ameloblastoma .

It occurs at young patients 16-20 y as asymptomatic painless swelling of the jaw ,

more than 90% are found in the mandibleusually in the posterior regions .

X-Ray : typically appears as unilocularRL,well demarcated, associated withunerupted 3rd molar.



Histopathology:

Three histopathological variant of unicystic ameloblastoma, have been described:



have been described:

Luminal unicystic ameloblastoma. The tumor is confined to the luminal surface of the cyst, it

consist of fibrous cyst wall with a lining that consist of ameloblastic epithelium, the over lying epithelial cell areloosely cohesive and resemble stellate reticulum.

Intra luminal unicystic Ameloblastoma. When one or more nodules of ameloblastoma projects from

the cystic lining in to the lumen of the cyst.

Mural unicystic ameloblastoma. There will be infiltration of the fibrous wall by typical

follicular or plexiform ameloblastoma.

unicystic ameloblastoma, the tumour consists of cyst-lining epithelium that still shows the typical features of ameloblastoma:loose epithelium and a rim of palisading cells facingthe stroma



the stroma



Treatment: enucleation forintraluminal plexiform patternhowever mural compound beneath

bone required marginal resection andperiodic follow up to ensureadequate removal.

Peripheral Ameloblastoma: Its uncommon, it accounts for about 1%-10% appear as

f



pppainless firm sessile, nodule on the gingiva which is small insize but continuously growing and has normal color. Most

lesions are clinically considered to represent a fibroma orpyogenic granuloma.

X-Ray: Seldom present, but occasionally superficial saucerization of

cortical plate. Sometimes tooth separation will show if located in the interdental papilla.

Histopathology: Resemble follicular pattern or plexiform pattern.

Treatment: Local surgical excision with small normal bone margin.

Malignant ameloblastoma and ameloblasticcarcinoma

It is a rare type account 1% of all ameloblastoma It



It is a rare type, account 1% of all ameloblastoma. Itproduce metastasis that not appear until 10y aftertreatment of primary tumor.

X-ray: it had ill defined margines with cortical bonedestruction due to aggressive behavior.

Histopathology:

The malignant ameloblastoma at primary and metastaticsite are similar to benign local course ameloblastoma, whileameloblastoma carcinoma has anaplasia and dysplasia of malignancy and necrosis.

Treatment: surgical removal , has poor prognosis.

Ameloblastic carcinoma combines the presence of epithelialnests with peripheral palisading and cytonuclear atypia



Calcifying odontogenic tumor(Pindborg tumour)

Its rare, account 1% of all odontogenictumor, its locally invasive, not capsulated

arise from remnants of dental lamina. Its most often present in patients between

30-50 years of age, there is no sexpredilection mostly occur in mandible in

posterior areas a painless, slow growingswelling is the most common presentingfeatures.



X-Ray: unilocualr or multilocular RLwith ill defined borders.

The lesion usually contains calcified

structures of varying size and densityand frequently associated with animpacted tooth, (mandibular molar).

Calcifying EpithelialOdontogenic Tumor



g

Differential Diagnosis : DC,Adenomatoied OT amelofibro-



Adenomatoied OT, amelofibro-

odontoma,

a few cases of peripheral

(extraosseous) calcifying epithelialOT have been reported which appearas sessile gingival mass most oftenon the anterior gingiva and showsuperficial cortical erosionradiographically.

Calcifying EpithelialOdontogenic Tumor



g

Histopathology:

f h f l h d l ll h



It consists of sheets of polyhedral cell withprominent intracellular bridges, pleomorphism,multinucleated prominent nucleoli accosionallyhyperchromatism, rare mitosis.

There is a large areas of apple-green

birefringenic amorphous, eosinphilic hyalinized(amyloid-like) extracellular material scatteredthrough out the epithelium and C.T. calcificationwithin the amyloid-like material and formconcentric rings. (liesengang ring calcification).

The peripheral type has less tendency forcalcification and prominent clear cell cytoplasmvariant.



Nuclear atypia, ample cytoplasm and pronounced intercellularbridging are typical of a calcifying epithelial odontogenic tumor



Extracellular material staining for amyloid with congored is another characteristic feature of a calcifyingepithelialodontogenic tumour



g



Treatment: It is less aggressive than

ameloblastoma so local resection

including soft tissue and normal bonesurrounding margins.

Adenomatoid OdontogenicTumor



! Associated with the crown of an impactedanterior tooth

! Painless expansion


! Well-defined expansile radiolucency ! Root

divergence, calcified flecks (“target”) !

Histology

! Thick fibrous capsule, clusters of spindle cells,columnar cells (rosettes, ductal) throughout

! Treatment - enucleation, recurrence is rare

Adenomatoid OdontogenicTumor



Calcifying odontogenic cyst (COC)

It is uncommon lesion may appears as cyst, solid pattern andassociated with odontoma.

Clinical :



Occurs at any part of teeth bearing area, commonly in anterior

region to molars, at any age predilection 2nd decade , may beintraosseous causing generalized expantion of buccal and lingualcortices, or extra osseous appears as localized swelling. There isno pain.

X-ray:- Well circumscribed unilocular RL containing RO and tooth –like structure .

Differential diagnosis: odontoma, ameloblastic fibro-odontoma. Histopathology: It has varying pictures

Cystic and solid , containing epithelial cells like ameloblastoma ,outer layer of palisaded columnar basal cells an dinner layer likestellate reticulum , in between there is enlarged eosinophilicepithelial cells lack nuclei ( ghost cells) and calcification arescattered within the epithelial and C.T.

Treatment: enucleation , recurrence are uncommon.

Calcifying odontogenic cyst closely resemblesameloblastoma,but the presence of large intraepithelial aggregates of ghost cells rules out the latter diagnosis



Histopathology: It has varying pictures

Cystic and solid , containing epithelial cellslike ameloblastoma , outer layer of

palisaded columnar basal cells and innerlayer like stellate reticulum , in betweenthere is enlarged eosinophilic epithelialcells lack nuclei ( ghost cells) and

calcification are scattered within theepithelial and C.T.

Squamous OT

Its rare, benign tumor with aggressive potential.



Its rare, benign tumor with aggressive potential.It arises from remnant of dental lamina, rest of malasses and overlying epithelium.

Clinical:

Sq. OT has been found in patient with averageage 38y. Occur in anterior region to molar, in

max and mandible, as painless gingival swellingassociated with mobility of teeth and its slowlygrowing.

X-Ray:

Unilocular RL lateral to roots which result in teethseparation but not root resorption.

Squamous Odontogenic Tumor



! Hamartomatous proliferation! Maxillary incisor-canine and mandibular

molar

! Tooth mobility common complaint !

Radiology - triangular, localized radiolucencybetween contiguous teeth

! Histology - oval nest of squamous epitheliumin mature collagen stroma

! Treatment - extraction of involved tooth andthorough curettage; maxillary - moreextensive resection; recurrences – treat withaggressive resection



Histopathology: Microscopically the tumor consist of

varying shaped (round and elongated)islands of stratified sq. epith. in mature

fibrous C.T. stroma, no polarization inepith.

Microcystic vaculation and individual cell

keratinized is common. Treatment: local excision or curettage.

Squamous OdontogenicTumor



Clear cell odontogenic tumor or carcinoma,

it is a rare jaw tumor that was first describedin 1985.

It is a malignant neoplasm, clear cytoplasm

indicate glycogen rich presecretory ameloblastcells. Clinically: It occurs in patient older than age 50y. 80%

develop in mandible as painful swelling or

sometime symptom free. Radiographically: uniloccular or multiloccular

RL with irregular margins.

Histopathology: Three patterns have been described:

The biphasic pattern appears as nests of varying size of clear cell or faint



varying size of clear cell or faint

eosinophilic cytoplasm admixed with moreeosinophilic polygonal epithelium cell.

monophasic type: characterized byappearance of cord or nests of clear cell in

a fibrous C.T. stroma. The third pattern has a resemblance to

amelobastoma in that the peripherial cellsof the clear cell islands may infrequently

demonstrate palisading and the lesionalcells don’t show nuclear or cytoplasmicpleomorphism, mitosis are rare andnecrosis is not a prominent feature.

Clear cell odontogenic carcinoma is characterised byclear cells forming epithelial nests



At higher magnification, clear cell odontogeniccarcinomais seen to contain clear cells as well as eosinophiliccells



Differential diagnosis• Intraosseous mucoepidemoid

carcinoma (+ve mucin stain) withi t l ll t



a prominent clear cell component.

•COT with clear cell (amyloid stain+ve in COT and –ve in Odontogeniccarcinoma)

•Metastatic clear cell neoplasm(renal cell carcinoma, clear cellbreast carcinoma).

Treatment: it has aggressive clinicalcourse need surgical radicalresection, metastasis to lung andL.N.

Mesenchymal OdontogenicTumors



!Odontogenic Myxoma!Cementoblastoma

Odontogenic Myxoma



!Originates from dental papilla or follicular mesenchyme

!Slow growing, aggressively invasive

!Multilocular, expansile; impactedteeth?!Radiology - radiolucency with septae

!Histology - spindle/stellate fibroblasts

with basophilic ground substance

!Treatment - en bloc resection, curettage

may be attempted if fibrotic



Odontogenic myxoma is composed of poorly cellularmyxoid material that surrounds pre-existing jaw bone



Cementoblastoma



! True neoplasm of cementoblasts! First mandibular molars

! Cortex expanded without pain ! Involved

tooth ankylosed, percussion ! Radiology -

apical mass; lucent or solid, radiolucent halowith dense lesions ! Histology - radiallyoriented trabeculaefrom cementum, rim of

osteoblasts

! Treatment - complete excision and toothsacrifice

Cementoblastoma



Mixed Odontogenic Tumors



! Ameloblastic fibroma, ameloblasticfibrodentinoma, ameloblastic fibro-odontoma, odontoma

!Both epithelial and mesenchymal cells!Mimic differentiation of developing tooth

!Treatment - enucleation, thorough

curettage with extraction of impacted tooth

!Ameloblastic fibrosarcomas - malignant,treat with aggressive en bloc resection



Ameloblastic Fibro-odontoma



This lesion is defined as a tumor withgeneral features of an ameloblasticfibroma but containing enamel and

dentin.

Some investigators believe that thisentity is but a stage in the

development of an odontoma;however, most agree that

progressive destructive tumors aretrue neoplasms.

Ameloblastic Fibro-odontoma:Clinical and Radiographic Features



Patient Age: Most common in the 5-12year age range with a mean of 10 years.

Gender Predilection: None.

Location: It is more common in the

premolar/molar regions of both jaws.Radiographic Features: Usually appears

as a well-defined unilocular or rarelymultilocular radiolucency with variable

amounts of calcified material which isradiopaque. Therefore, it may appear asa mixed, radiolucent-radiopaque lesion.

Ameloblastic Fibro-odontoma:Histologic Features



The soft tissue component isidentical to the ameloblastic fibroma.

The calcified portion consists of fociof enamel and dentin matrix

formation in close relationship to theepithelial structures.

Ameloblastic Fibro-odontoma:Treatment and Prognosis



The ameloblastic fibro-odontoma isusually treated by conservative

curettage with the lesion separatingeasily from the surrounding bone.

Prognosis is excellent and recurrenceis unusual.



Ameloblastic Fibrosarcoma



This lesion is considered themalignant counterpart of the

ameloblastic fibroma in which themesenchymal portion shows features

of malignancy.

The ameloblastic fibrosarcoma mayarise de novo or there may be amalignant transformation of an

ameloblastic fibroma.

Ameloblastic Fibrosarcoma:Clinical and Radiographic Features



Patient Age: The mean age forpatients with ameloblasticfibrosarcoma is 26 years.

Gender Predilection: Males 2:1.Location: 75 % have occurred in the

mandible.

Radiographic Features: Appear asan ill-defined, destructive,

radiolucent lesion.

Ameloblastic Fibrosarcoma:Histologic Features



The epithelial component of thistumor appears histologically benign.

The mesenchymal portion is highly

cellular. The cells arehyperchromatic and quitepleomorphic. Mitoses are usually

prominent.

Ameloblastic Fibrosarcoma: Additional Features, Treatment &

Prognosis



Pain and swelling are typicallyassociated with this tumor. Rapidclinical growth is another common

feature.

Radical surgical excision is thetreatment of choice.

The long-term prognosis is difficult toascertain because of the smallnumber of reported cases.



Odontoma



The odontoma is the most commonodontogenic tumor.

It is not a true neoplasm but rather isconsidered to be a developmental

anomaly (hamartoma).Two types of odontomas are recognized:

•Compound: this type of odontoma iscomposed of multiple small tooth-like

structures.

•Complex: this lesion is composed of aconglomerate mass of enamel and dentin,which bears no anatomic resemblance to a

Odontoma: Clinical Features



Patient Age: Most cases arerecognized during the second decadeof life with a mean of 14 years.

Gender Predilection: Approximately

equal.Location: Somewhat more common

in the maxilla. The compound type

is more often in the anterior maxillawhile the complex type occurs moreoften in the posterior regions of

either jaw.

Odontoma: Radiographic Features



Early lesions are radiolucent withsmooth, well-defined contours.

Later a well-defined radiopaque

appearance develops.The compound type shows apparent

tooth shapes while the complex typeappears as a uniform opaque mass

with no apparent tooth shapespresent.

Odontoma: Additional Features



Most odontomas are small and do notexceed the size of a normal tooth in theregion.

However, large ones do occur and these

may cause expansion of the jaw.Most odontomas are asymptomatic and as

a result are discovered upon routineradiographic examination.

Odontomas may block the eruption of apermanent tooth and in these cases are

often discovered when “searching for” the

“ ”

Odontoma: Histologic Features



The compound odontoma iscomposed of enamel, dentin andcementum arrange in recognizabletooth forms; some enamel matrix

may be retained in immature andhypomineralized specimens.

The complex odontoma is composedof enamel, dentin and cementum but

these tissues are arranged in arandom manner that bears no

morphological resemblance to a

Odontoma: Treatment andPrognosis



Odontomas are treated by simplelocal excision and the prognosis isexcellent.



Tumors of Odontogenic

Ectomesenchyme

(Central) Odontogenic Fibroma:Clinical Features

Fewer than 70 cases have been reported



pin the English literature. (VS hyperplasticfollicle when associated with uneruptedtooth)

Patient Age: Patients have ranged in agefrom 9-80 years old with a mean of 40years.

Gender Predilection: Females, 7.4:1 inone study.

Location: Sixty percent occur in themaxilla where most are located anterior tothe first molar. When in the mandible,

Odontogenic Fibroma:Radiographic Appearance



The odontogenic fibroma usuallyappears as a well-defined, unilocularradiolucency. It is often associatedwith the apical area of an eruptedtooth.

Larger lesions are often multilocular.

Many odontogenic fibromas havesclerotic borders.

Root resorption is common.

Odontogenic Fibroma: AdditionalFeatures



Small odontogenic fibromas areusually asymptomatic.

The larger lesions may be associated

with localized bony expansion of the jaw or with the loosening of adjacentteeth.

Odontogenic Fibroma: HistologicFeatures

Some authors have described two



separate types of odontogenic fibromas.

The simple odontogenic fibroma iscomposed of stellate fibroblasts arranged

in a whorled pattern with fine collagenfibrils and a lot of ground substance.

Foci of odontogenic epithelium may ormay not be present.

Occasionally, foci of dystrophiccalcification may be present.

Odontogenic Fibroma: HistologicFeatures



WHO type odontogenicThe appears as a fairly cellularfibromafibrous connective tissue with

collagen fibers arranged ininterlacing bundles.

Odontogenic epithelium in the formof long strands or isolated nests is

present throughout the lesion.

Calcifications composed of cementoidand/or dentinoid may be present.

Odontogenic Fibroma: Treatmentand Prognosis



The odontogenic fibroma is usuallytreated by enucleation andcurettage.

There have been few recurrences,the prognosis is good.



Developmental non-odontogenic cysts

The remaining 5% of cysts within the jaws are made up of non-odontogenic cysts.

Developmental non-odontogenic cysts within the jaws must arise from epithelium



not associated with tooth development.

In the past, several entities were described as fissural cysts because they were

suspected to have arisen from tissue entrapped during fusion across various

fissures during facial development.

It has now been clearly shown that the only true fissural cyst is the midpalatal cyst

of infants.Other so-called fissural cysts such as the globulomaxillary cyst, the median alveolar

cyst, and the median mandibular cyst are most likely to be developmental or

inflammatory odontogenic cysts.

The other two lesions within this category are the nasopalatine duct cyst,

which arises from the cystic degeneration of the vestigule bilateral oro-nasal ducts,and the nasolabial cyst, which is a soft-tissue cyst arising from dystopic rests of the

naso-lacrimal ducts.

Nonodontogenic Cysts

! C C



!Incisive Canal Cyst!Stafne Bone Cyst

!Traumatic Bone Cyst

!Surgical Ciliated Cyst (of Maxilla)

l i d



Nasopalatine duct cyst Midpalatal cyst of infants

Nasolabial cyst

Globulomaxillary cyst dermoid cyst

N i h li l



Nonepithelial. Idiopathic bone cavity (traumatic,

solitary, hemorrhagic bone cyst)

b. Aneurysmal bone cyst c. Stafne's mandibular lingual cortical

defect



Sublingual dermoid cyst. This is anunusually large specimenbut appears even larger because thepatient is raising and protruding hertongue. This cyst, unlike a ranula,can be seen to have a thick wallbecause it has arisen in the deepertissues of the floor of the mouth



Nasopalatine duct cyst



The nasopalatine duct cyst, also known as

the incisive canal cyst is formedfrom cystic degeneration of the oronasal

ducts thatconnect the nasal cavity to the oral cavity

during development.

Incisive Canal Cyst

!D i d f ith li l t f th( )



Derived from epithelial remnants of thenasopalatine duct (incisive canal)

!4th to 6th decades

!Palatal swelling common, asymptomatic!Radiographic findings

!Well-delineated oval radiolucency betweenmaxillary incisors, root resorption occasional

!Histology!Cyst lined by stratified squamous or

respiratory epithelium or both

Incisive Canal Cyst



Nasopalatine cyst. The usualappearance is a rounded or pear-shapedarea of radiolucency, mainly in themidline.

Incisive Canal Cyst

!T t t i t f i l



!Treatment consists of surgicalenucleation or periodic radiographs

!Progressive enlargement requires

surgical intervention



Nasopalatine cyst. Typical presentation with adome-shapedbluish enlargement overlying the incisive canal

Nasopalatine cyst. The lining, in partat least, may consist of respiratory (ciliated columnar)epithelium,



“Globulomaxillary” Cyst

Cyst of theglobulomaxillary

area



Stafne Bone Cyst

!Submandibular salivary gland depression



!Submandibular salivary gland depression!Incidental finding, not a true cyst

!Radiographs - small, circular, corticated

radiolucency below mandibularcanal!Histology - normal salivary tissue

!Treatment - routine follow up

Stafne's mandibular lingual cortical defect

This entity is also known by several otherterms including lingual mandibula bonecavity, static bone cavity, and lingual

salivary gland defect. This is an

asymptomatic lesion



asymptomatic lesion.

It usually occurs in adults over the age of 25. Radiographically, the lesion is a solitaryradiolucency below the inferior alveolar

canal near the angle region of the mandible.The lesion is usually oval and exhibits nogrowth over long periods of time. Theperiphery is smooth and symmetric. Thelesion is benign, has not growth potential,and a classic radiographic appearance thatmakes diagnosis without biopsy possibleand observation without active interventionthe treatment of choice.

Stafne Bone Cyst



Traumatic Bone Cyst

!Empty or fluid filled cavity associatedwith jaw trauma (50%)



with jaw trauma (50%)


!Radiolucency, most commonly in body or

anterior portion of mandible!Histology - thin membrane of fibrous

granulation

!Treatment - exploratory surgery mayexpedite healing

Traumatic Bone Cyst



Surgical Ciliated Cyst

!May occur following Caldwell Luc



!May occur following Caldwell-Luc!Trapped fragments of sinus epithelium

that undergo benign proliferation

!Radiographic findings!Unilocular radiolucency in maxilla

!Histology

!Lining of pseudostratified columnar ciliated!Treatment - enucleation

Surgical Ciliated Cyst



Aneurysmal Bone Cyst

!Large vascular sinusoids (no bruit)

!Not a true cyst; aggressive reactive!G i l f h d f i



!Not a true cyst; aggressive, reactive!Great potential for growth, deformity!Multilocular radiolucency with cortical expansion!Mandible body

!Simple enucleation, rare recurrence

Aneurysmal bone cyst

The aneurysmal bone cyst is not unique to the maxillofacialcomplex. It is a lesion that has a predilection for femalesand occurs most commonly in the vertebral column and thelong bones. In the craniofacial skeleton, the mandible isaffected most often. The patient often complains of

swelling over a localized area and pain. It is felt that thislesion may develop from some other primary lesion such as



g plesion may develop from some other primary lesion such asthe central giant-cell granuloma that undergoes alterationin local hemodynamics. Radiographically, the lesion is aradiolucency with a multilocular or honeycombedappearance. The sclerotic bone margins seen in most cystsmay be absent. Histologically, the lesion is made up of afibrous connective tissue stroma with multiple cavernousand sinusoidal spaces with multinucleated giant cellswithin the stroma.

Enucleation is the treatment of choice with hemorrhage

during the removal being risk because of the large numberof vascular spaces within the lesion. Hemorrhage is usuallycontrolled easily once the entire lesion is removed; whentreating these lesions, the goal should be rapid enucleationto prevent blood loss with control of bony bleeding withbone wax or packing. The lesion does not recur aftersimple enucleation.

Odontogenic Cysts And Tumors (2).ppt

Documents

Transcript of Odontogenic Cysts And Tumors (2).ppt