5. odontogenic tumor (1)

Neo: new; Plasia: formation. A neoplasm is defined as an uncoordinated proliferation of tissue, the growth of which

persists in a potentially unlimited fashion, even after cessation of the stimulus which evoked the change.

Definition

• Benign tumors represent a new uncoordinated growth.

• Benign tumors are slowly growing• No metastases• Histologically they tend to resemble the

tissue of origin.

Clinical Features

• Insidious onset • Grow slowly• Painless• Do not metastasize• Not life threatening (unless they interfere

with a vital organ by direct extension).

• Benign tumors are detected through:– Enlargement of the jaws– Accidentally during a radiographic examination– While investigating the reason of missing tooth

• When a preliminary dignosis of tumor is made:– a full radiologic examination should be made to

fully document the extent and characteristics of the lesion.

Radiographic features

Location:• Important in establishing the differential

diagnosis• Odontogenic lesions occur above the inferior

alveolar nerve canal.• Vascular or neural lesions may originate inside

the mandibular canal• Cartilagenous tumors occur in jaw locations

with residual cartilagenous cells(around mandibular condyle)

Periphery and shape• Smooth, well defined, and sometimes

corticated.(Because benign tumors enalrge slowly by

formation of additional internal tissue)• Sometimes tumor produce calcified material.(Mature=Center / Immature:periphery)

Internal structure• Radiolucent• Radiopaque• Mixed:

– Residual bone– Calcified material

Internal pattern is characteristic for specific types of tumors and may help with the diagnosis.

Effects on surrounding structures• Displacement of teeth or bony cortices(Growth is slow enough to allow remodeling)• Resorption of roots

CLASSIFICATIONBENIGN NEOPLASMS

Odontogenic tumors Non-odontogenic tumorsA. Epithelial origin

1. Ameloblastoma2. Adenomatoid odontogenic tumor3. Calcifying epithelial odontogenic tumor4. Squamous odontogenic tumor

B Mixed origin 1. Ameloblastic fibroma

2. OdontomesC Mesodermal origin

1. Myxoma & Myxofibroma2. Odontogenic fibroma3. Cementifying fibroma4. Periapical cemental dysplasia5. Benign cementoblastoma6. Familial multiple cementoma

A. Hyperplastic lesions1. Polyp2. Epulis3. Giant cell granuloma

B. Epithelial origin1. Papilloma2. Adenoma3. Pigmented nevus4. Keratoacanthoma

C. Mesenchymal1. Connective tissue origina. Fibromab. Lipoma / Fibrolipomac. Haemangiomad. Lymphangiomae. Chondromaf. Osteoma

C. Mesenchymal2. Muscle tissue origina. Leiomyomab. Rhabdomyomac. Granular cell myoblastoma3. Nerve tissue origina. Neurofibromab. Neurilemmomac. Melanotic progonoma

Common Clinical FeaturesAge of occurrence: Varies with each tumor

Sex predilection: Varies with each tumorSymptoms: Most of the tumors present as a painless, gradually / rapidly enlarging swelling. If infected, pain may be present. Other symptoms include facial deformity, mobility in teeth, numbness.

ODONTOGENIC TUMORS

Common Clinical FeaturesODONTOGENIC TUMORS

Signs: The swelling has the following features:Inspection: usually single, round or oval, well-

defined boundaries, smooth or nodular surface, normal overlying skin or mucosa, expansion of jaw bone, obliteration of vestibule

Palpation: Normal temperature of the overlying skin or mucosa, non-tender, consistency is bony hard (if entirely within bone); ‘egg-shell crackling’ (if overlying bone is thin); firm (if no bone coverage), teeth mobility, paraesthesia

Additional features: missing tooth or normal dentition, displacement of teeth, pathological jaw fracture, signs of inflammation if tumor is infected

Common Radiographic FeaturesODONTOGENIC TUMORS

Ameloblastoma

• Definition• The ameloblastoma, a true neoplasm of

odontogenic epithelium, is a persistent and locally invasive tumor; it has aggressive but benign growth characteristics.

• Ameloblastomas may be divided into the solid/multicystic type, and unicystic type.

• Clinical Features• Occur more in men, more often in black• Ameloblastomas grow slowly, and few, if any, symptoms occur in

the early stages.• Usually the patient eventually notices gradually increasing facial

asymmetry• Swelling of the cheek, gingiva, or hard palate has been reported as

the chief complaint in 95% of untreated maxillary ameloblastomas.

• The mucosa over the mass is normal, but teeth in the involved region may be displaced and become mobile.

Signs: The swelling has the following features:Inspection: single, round or oval, well-defined boundaries, smooth

or lobulated, normal overlying skin or mucosa (ulcerated if large), expansion of jaw bone in all the 3 planes, obliteration of vestibule

Palpation: normal temperature of the overlying skin or mucosa, non-tender, consistency is bony hard (if entirely within bone); ‘egg-shell crackling’ (if overlying bone is thin); firm (if no bone coverage) or soft (if unicystic), teeth mobility, paraesthesia

Additional features: missing tooth or normal dentition, displacement of teeth, pathological jaw fracture, thin straw colored fluid on aspiration (unicystic variety) signs of inflammation if tumor is infected

ODONTOGENIC TUMORSAmeloblastoma(‘locally malignant’)

Clinical Features

ODONTOGENIC TUMORS

Type of lesion: radiolucentSite: usually mandibular 3rd molar-ramus regionSize: large lesionShape: unilocular (round or oval), multilocular (‘soap

bubble’, ‘honeycomb’) with locules separated by bony septae

Number: singleOutline: regular or scallopedBorder: well-defined hyperostotic (‘partially hyperostotic’)Contents: homogenous radiolucencyAdditional features: impaction of tooth with displacement

deep in the jaw, expansion of jaw bone bucco-lingually, antero-posteriorly and vertically, displacement & resorption of roots, displacement of inferior alveolar canal, obliteration of maxillary antrum, thinning of cortical plates, thinning of inferior border of mandible, ‘cyst-in-cyst’ appearance, pathological jaw fracture

Ameloblastoma(‘locally malignant’)

Radiographic Features

• An untreated tumor may grow to great size and is more of a concern in the maxilla, where it can extend into vital structures and reach into the cranial base

• Tumors that develop in the maxilla may extend into the paranasal sinuses, orbit, nasopharynx, or vital structures at the base of the skull.


• Location• Most ameloblastomas (80%) develop in the

molar ramus region of the mandible, but they may extend to the symphyseal area.

• Most lesions that occur in the maxilla are in the third molar area and extend into the maxillary sinus and nasal floor.

• Periphery• well defined and frequently delineated by a cortical border.• The periphery of lesions in the maxilla is usually more ill

defined.

• Internal Structure• varies from totally radiolucent to mixed with the presence of

bony septa creating internal compartments.• Septa can be straight but are more commonly coarse and curved• Generally the loculations are larger in the posterior mandible

and smaller in the anterior mandible.

• Effects on Surrounding Structures.• There is a pronounced tendency for ameloblastomas to cause

extensive root resorption• Tooth displacement is common

Ameloblastoma

Differential Diagnosis:Dentigerous cyst, odontogenic keratocyst, giant cell

granuloma, odontogenic myxoma, and ossifying fibroma

Ameloblastoma(‘locally malignant’)

ODONTOGENIC TUMORS

Treatment• The surgical procedure should take into account the

tendency of the neoplasm to invade adjacent bone beyond its apparent radiographic margins.

• CT and MRI are useful in determining the exact extent of the tumor.

• The maxilla is usually treated more aggressively because of the tendency of ameloblastoma to invade adjacent vital structures.

• Radiation therapy may be used for inoperable tumors, especially those in the posterior maxilla.

BENIGN NEOPLASMS

Odontogenic tumorsA. Epithelial origin

1. Ameloblastoma2. Adenomatoid odontogenic tumor3. Calcifying epithelial odontogenic tumor4. Squamous odontogenic tumor5. Ameloblastic fibroma6. Odontomes

B. Mesodermal origin1. Myxoma & Myxofibroma2. Odontogenic fibroma3. Cementifying fibroma4. Periapical cemental dysplasia5. Benign cementoblastoma6. Familial multiple cementoma

Non-odontogenic tumors

CLASSIFICATION

• Adenomatoid odontogenic tumors are uncommon nonaggressive tumors of odontogenic epithelium in variety of patterns mixed with mature connective tissue stroma.

• Can be central or peripheral• Central tumors can be follicular or extrafollicular• 73% of central lesions are of the follicular type

Adenomatoid Odontogenic Tumor(‘AOT’)

Age of occurrence: mostly in 2nd & 3rd decades of life

Sex predilection: 2:1 females predilection

Symptoms: Most of the tumors present as a painless, gradually enlarging swelling. Sometimes asymptomatic, being discovered radiographically.

Site: almost 75% of cases involve maxillary anterior teeth

ODONTOGENIC TUMORSAdenomatoid Odontogenic Tumor

(‘AOT’)


(‘AOT’)Clinical Features

Signs: The swelling has the following features:Inspection: single, round or oval, well-defined

boundaries, smooth, normal overlying skin or mucosa, little expansion of jaw bone, obliteration of vestibule

Palpation: normal temperature of the overlying skin or mucosa, non-tender, consistency is bony hard (if entirely within bone); ‘egg-shell crackling’ (if overlying bone is thin); firm (if no bone coverage)

Additional features: normal dentition, displacement of teeth

Type of lesion: radiolucent radiopacities develop in about two thirds of cases.

Site: maxillary anterior regionOften does not attach at the cementoenamel junction but

surrounds a greater area of the toothSize: about 3 cms in diameterShape: unilocular (round or oval)Number: singleOutline: regularBorder: well-defined hyperostoticContents: homogenous radiolucency interspersed with radiopaque

foci (‘driven snow’ appearance)Additional features: sometimes impaction of tooth, little expansion

of jaw bone, displacement & resorption of roots, thinning of cortical plates



(‘AOT’)


(‘AOT’)

Differential Diagnosis:No radiopaque foci – ameloblastoma,

ameloblastic fibroma, odontogenic fibroma, primordial cyst, lateral periodontal cyst

Radiopaque foci – CEOC, CEOTManagement: surgical enucleation

Image: Atlas of Oral Diagnostic Imaging by Higashi

An adenomatoid odontogenic tumor in the region of the right maxillary canine and lateral incisor. Calcifi cation is present within the tumor mass, and the canine and lateral incisor have been displacedby the lesion.

Examples of adenomatoid odontogenic tumor with various amount of internal calcification.A, A cropped panoramic film with a totally radiolucent lesion associated with a mandibularcuspid. B, A lesion with sparse pebblelike calcifications associated with a maxillary cuspid. C, A lesion related to a maxillary lateral incisor with abundant calcification.

• Calcifying epithelial odontogenic tumors (CEOTs) are rare neoplasms.

• They account for about 1% of odontogenic tumors

• These tumors usually are located within bone and produce a mineralized substance

• Epithelium resembles the stratum intermedium of the enamel organ

Calcifying Epithelial Odontogenic Tumor(‘CEOT’, Pindborg tumor)

Age of occurrence: mostly in middle aged patients

Sex predilection: more common in men

Symptoms: Most of the tumors present as a painless, gradually enlarging swelling. Sometimes non-eruption of tooth / asymptomatic, being discovered radiographically

A CEOT is less aggressive than the ameloblastoma

Site: majority in mandibular premolar-molar region

ODONTOGENIC TUMORSCalcifying Epithelial Odontogenic Tumor

(‘CEOT’, Pindborg tumor)Clinical Features

Signs: The swelling has the following features:Inspection: single, round or oval, well-defined

boundaries, smooth, normal overlying skin or mucosa, little expansion of jaw bone, obliteration of vestibule

Palpation: normal temperature of the overlying skin or mucosa, non-tender, consistency is bony hard (if entirely within bone); ‘egg-shell crackling’ (if overlying bone is thin); firm (if no bone coverage)

Additional features: missing tooth, displacement of teeth

Type of lesion: unilocular or multilocular with numerous scattered, radiopaque foci of varying size and density.

The most characteristic and diagnostic finding is theappearance of radiopacities close to the crown of the embedded toothSite: mandibular premolar-molar regionSize: about 3 cms in diameterShape: somewhat irregularNumber: singleOutline: somewhat irregularBorder: well-defined, at times diffuseContents: homogenous radiolucency interspersed with diffuse radiopacitiesAdditional features: impaction of tooth is common, little expansion of jaw bone, displacement & resorption of roots, thinning of cortical plates



(‘CEOT’, Pindborg tumor)


(‘CEOT’, Pindborg tumor)

Differential Diagnosis: CEOC, AOT, intermediate stages of fibro-osseous lesions

Management: The treatment of the CEOT is more conservative than the ameloblastoma,with local resection

Image: Lucas’s Pathology of Tumors of the Oral Tissues, 5 th edition

The tumor appears asa mixed radiolucent-radiopaque lesion associated with an unerupted tooth.

Calcifying odontogenic tumor, or Pindborg tumor (arrows).

BENIGN NEOPLASMS

Odontogenic tumorsA. Epithelial origin

1. Ameloblastoma2. Adenomatoid odontogenic tumor3. Calcifying epithelial odontogenic tumor4. Squamous odontogenic tumor5. Ameloblastic fibroma6. Odontomes

B. Mesodermal origin1. Myxoma & Myxofibroma2. Odontogenic fibroma3. Cementifying fibroma4. Periapical cemental dysplasia5. Benign cementoblastoma6. Familial multiple cementoma

Non-odontogenic tumors

CLASSIFICATION

• The term odontoma is used to identify a tumor that is radiographically and histologically characterized by the production of mature enamel, dentin, cementum, and pulp tissue.

• It may vary from nondescript masses of dental tissue referred to as a complex odontoma to multiple well-formed teeth (denticles) of a compound odontoma.

• Odontomas are the most common odontogenic tumor. • They often interfere with the eruption of permanent teeth

Odontome(‘complex/compound composite odontome’, Odontoma)

Age of occurrence: mostly in young adultsSex predilection: (compound )no sex predilection.

(complex) 60% occur in women

Symptoms: mostly asymptomatic, being discovered radiographically for non-eruption of tooth, sometimes slowly enlarging swelling

Site: complex more common in mandibular premolar-molar region, compound more common in maxillary anterior region

ODONTOGENIC TUMORSOdontome

(‘complex/compound composite odontome’, Odontoma)

Clinical Features

Type of lesion: radiopaque mass surrounded by a radiolucent line and further by a radiopaque line, ‘mixed’ in early stages

Site: mandibular premolar-molar region / maxillary anterior region

Size: complex can be large, compound usually smallShape: round or ovalNumber: singleOutline: regularBorder: well-defined hyperostoticContents: Irregular mass of calcifi ed tissue (‘complex’) or a

number of toothlike structures or denticles that look like deformed teeth(‘compound’)

Additional features: associated with supernumerary tooth, impaction of tooth, little expansion of jaw bone, displacement & resorption of roots, thinning of cortical plates






Images: Atlas of Oral Diagnostic Imaging by Higashi

Differential Diagnosis:in the early stage: CEOC, AOT,

intermediate stage of fibro-osseous lesions

in the mature stage: mature stage of fibro-osseous lesions, osteoma

Management: surgical removal to allow eruption of impacted tooth and avoid cystic changes



Odontogenic Myxoma• Odontogenic myxomas are uncommon, accounting for only 3% to 6%

of odontogenic tumors.

• They are benign, intraosseous neoplasms that arise from odontogenic ectomesenchyme

• These myxomas are not encapsulated and tend to infi ltrate the surrounding cancellous bone but do not metastasize.

• If odontogenic myxomas have a sex predilection, they slightly favor females.

• Second decade of life• 25% recurrence rate

• Radiographic picture• More commonly affect the mandible by a margin of 3 : 1. premolar/ molar

area• Residual bone trapped within the tumor will remodel into curved and straight,

coarse or fine septa.• A characteristic septa identified with this tumor is a straight, thin-etched septa

(a tennis racket – like or stepladder-like pattern)(rare)• The tumor displaces and loosens teeth but rarely causes resorption of teeth

• Differential diagnosis:• Ameloblastoma, central giant cell granuloma

Treatment:• Resection with margin

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5. odontogenic tumor (1)

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