BENIGN TUMORS OF OROFACIAL REGION

TYPES OF BENIGN TUMORS1. ODONTOGENIC: These are derived from tooth forming elements. The more primitive the dental tissue found, the

more aggressive the tumor and vice versa Only found in the jaws Locally aggressive and rarely malignant

2. NON ODONTOGENIC : They are not derived from dental tissues They can be found in other regions of the body.

CLASSIFICATION BENIGN ODONTOGENIC TUMORS:1.EPITHELIAL TUMORS: Ameloblastoma Calcifying epithelial odontogenic tumor Adenomatoid odontogenic tumor Squamous odontogenic tumor2.MESENCHYMAL TUMORS: Odontogenic fibroma Cementoblastoma Odontogenic myxoma Cementifying fibroma3.MIXED TUMORS(EPITHELIAL& MESENCHYMAL): Odontoma Ameloblastic fibroma Ameloblastic fibro-odontome

NONODONTOGENIC TUMORS:

1. FIBRO-OSSEOUS TUMORS Ossifying fibroma Juvenile ossifying fibroma2. LANGERHANS CELL DISEASE Chronic localized Chronic disseminated Acute disseminated3. GIANT CELL LESIONS: Central giant cell granuloma Giant cell tumor Hyperparathyroidism Cherubism Aneurysmal bone cyst

4. NEUROGENIC TUMORS Schwannoma Neurofibroma5. OSTEOID OSTEOMA AND

OSTEOBLASTOMA6. OSTEOMA

CHRONDROMA7. DESMOPLASTIC FIBROMA

AMELOBLASTOMA Benign but locally aggressive tumor of the jaw The name of the tumor derives from the fact the

diagnostic cells resemble ameloblast Histologically these cells are columnar , basally

staining arranged in palisaded along the basement membrane.

They are believe to express amelogenin, a precursor of enamel

They are divided into three distinct types:1. Solid2. Cystic3. peripheral

PATHOGENESIS OF AMELOBLASTOMA

1. Over expression of antiapoptotic gene Bcl22. TNF alpha3. MMPs and transforming growth factors4. Low proliferation rate ki675. No p53 mutation

SOLID AMELOBLASTOMA

Various histological patterns including follicular, plexiform, and granular cell variants….does not have affect treatment or prognosis

SITE: most common in mandible esp angle ,ramusarea. Rare in maxilla, but infiltration is much faster as marrow spaces and cavities offer less resistanceOCCURRENCE: third to fifth decade of life. Male to female ratio is approx equalCLINICAL APPEARANCE: 1. slow growing, expansile lesion.2. locally aggressive with buccal and lingual

cortical expansion,root resorption is seen

INVESTIGATIONS:1. Radiographic evaluation, OPG shows multilocular

radiolucency with root resorption and displacement of teeth

2. CT scan in case of larger lesions and esp maxillary ameloblastoma

3. Aspiration of the swelling will reveal nothing in case of solid ameloblastoma

4. Incisional biospy, shows typical pallisaded columnar cells resembling ameloblasts.

TREATMENT:1. For solid lesions, enucleation has a high recurrence rate 60-

80%. Cells are present beyond the radiographical margin.2. Surgical resection should be with a 1 cm safe radiological

margin and soft tissue clearance if supraperiosteal.3. IAN is sacrificed4. Maxillary resections often end in maxillectomy with wide

margin clearance from the sinus, nasal and infratemporal regions

5. After surgical resections or curettage , liquid nitrogen cryotherapy plays a good role

RECONSTRUCTION:1. For the mandible, segmental defects of 5 cm can

be reconstructed with bone grafts most commonly iliac crest.

2. For more larger defects free osseofasiocutaneous flaps may be used.. DCIA and free fibular flap.

3. Reconstruction plates are used as adjuncts to grafts or as an interim treatment modality

4. For maxilla, depending upon the defect, local, regional flaps can be used but prosthetic options serve the best purpose

CYSTIC AMELOBLASTOMA Unicystic ameloblastoma, less aggressive variant. Most common in younger population. Mostly located in posterior mandible and anterior

maxilla All other features are the same Enucleation alone may be insufficient, the cavity

should be treated with peripheral ostectomy, or liquid nitrogen or both.

PERIPHERAL AMELOBLASTOMA Occurs in gingiva with no bony involvement Painless, sessile growth, firm and exophytic Complete excision solves the problem

CALCIFYING EPITHELIAL ODONTOGENIC TUMOR

Also called Pindborg tumor after he described it in 1955. derived from stratum intermedium

Wide age range from 13- 80 yrs, no gender predeliction.

SITE: mandibular premolar area.CLINICAL BEHAVIOUR: most are asymptomatic, slow growing in nature. In maxilla may cause, nasal obstruction, proptosis or epistaxisINVESTIGATIONS:1. On radiographs, they appear as mixed radiolucent

radiopaque, unilocular or mutilocular lesions2. Biopsy will reveal sheets of epithelial cells in a stroma

filled with hyaline like homogenous material and concentric calcification rings called liesegang rings

TREATMENT: Less aggressive than ameloblastoma, however

malignant variant (odontogenic carcinoma) has been identified.

Wide excision with 5- 10 mm margin, which in mandible may result in marginal or segmental resection followed by reconstruction.

Recurrence rate is 14-20%

ADENOMATOID ODONTOGENIC TUMOR

Occurs only in jaws. Resemblance to structures present in enamel formation

OCCURRENCE: most common in females; age of occurrence is 5 -30 yrs.

SITE: anterior maxilla, impacted teeth RADIOGRAPHIC APPEARANCE: pear shaped

radiolucency with speckled opaque foci indicating calcification. Divergence of roots is seen

TREATMENT: simple enucleation seems all that is necessary.

SQUAMOUS ODONTOGENIC TUMOR Rare tumor originates from the rest of malassez

in the periodontium. Occurrence in both mandible(post) and maxilla

(ant) Presents with pain and tooth mobility Radiographic appearance is a semilunar

radiolucency associated with erupting teeth. Treatment is conservative excision

MESENCHYMAL ODONTOGENIC TUMORS

CEMENTOBLASTOMA Rare tumor , most common in second and third

decade of life, lower molar region. Intimately associated with the root of tooth.

Tooth remains vital and symptoms of low grade pain and cortical expansion are present.

RADIOGRAPH: radiopaque lesion attached to and surrounding the root of a tooth. Must be distinguished from focal sclerosing osteomyelitis, odontoma and hypercementosis.

HISTOLOGY: Difficult to distinguish cementum and bone. It is cemental variant of osteoblastoma

TREATMENT: surgical removal of tooth and lesion. Peripheral ostectomy is recommended

ODONTOGENIC MYXOMA 15-20% of odontogenic tumors. Second most

common tumorOCCURRENCE: second through fourth decade of

life. More common in females. Two thirds occur in mandible and one third in maxilla.

CLINICAL APPEARANCE: presents as a swelling locally aggressive.

RADIOGRAPH: similar to ameloblastoma, multilocular radiolucency

HISTOLOGY: loose mesenchymal tissue . Derived from dental pulp or primitive dental papilla. Bland histological appearance.

TREATMENT:1. Less aggressive than ameloblastoma.2. Enucleation or radical curettage with peripheral

ostectomy.3. In larger lesions perforating the cortex,

segmental resection of mandible or hemimaxillectomy in maxilla may be required.

4. Physiochemical adjuncts can also be employed like carnoys’s solution or liquid nitrogen.

MIXED TUMORSODONTOMA

Developmental anomalies. Most common tumor. Consists of irregularly arranged mature dental tissues.

May present as a swelling or infected lesion if they erupt. Often replacing a missing tooth. Most commonly found in the mandible molar region.

TYPES: complex and compound odontome.1.COMPLEX: most common in posterior mouth.

Amorphous conglomeration of dental tissues consisting of enamel,dentin and cementum. Radiograph shows gives a radiopaque mutilobular appearance.

2.COMPOUND: common in anterior jaw.contains numerous denticles or tooth like fragments (each containing enamel with dentin and pulp)

3. Radiographical resembles a bag of teethTREATMENT: enucleations cures the problem, no recurrences

AMELOBLASTIC FIBROMAOCCURRENCE: young people second and third

decade of life. No gender predilection. Most common site is mandibular bicuspids area.

RADIORAPHIC VIEW: unilocular/ multilocular well defined radiolucency. Teeth may be displaced but rarely resorbed.

HISTOLOGY: islands of odontogenic epithel;ium in myxomatous stroma

TREATMENT: encapsulated lesion so enucleation is done. Malignant variant is ameloblastic fibrosarcoma.

AMELOBLASTIC FIBRO-ODONTOMA Combination of ameloblastic fibroma with an

odontoma.(complex or compound). Radiographically a mixed radiopaque/ radiolucent

lesion Treatment is enucleation

NON ODONTOGENIC TUMORS FIBRO OSSEOUS LESIONS1. Fibrous dysplasia2. Ossifying fibroma3. Cemento-osseous dysplasiaOSSIFYING FIBROMA:replacement of normal bone by fibrous tissue and variable amount of newly formed bone and cementum like structuresCLINICAL FEATURES: 1. Painless, slowly growing swelling2. Third and fourth decade of life3. Females are more commonly affected4. Mandible(premolar –molar ) most commonly affected5. Juvenile OF is a variant, occurring in children and

involving the craniofacial complex

RADIOLOGICAL FEATURES:1. Well defined radiolucency with internal

calcifications. 2. The borders may be sclerotic3. Root displacement and resorption is seen HISTOLOGY:Fibrous stroma with bony trabaculae and cementum like spherules TREATMENT:1. Complete surgical excision2. Stripping of the lesion is easy3. Root that are resorbed are removed

FIBROUS DYSPLASIA Monostotic Polyostotic (Mc Cune Albright Syndrome)

Usually in females In second and third decade of life Related to hormones Maxilla more favored site Ground glass appearance on radiograph The lesion’s margins are not well demarcated Similar histological picture as ossifying fibroma Recontouring after puberty

LANGERHANS CELL DISEASEFormerly known as histiocytosis X and three clinically distinct diseases1. Eosinophilic granuloma2. Hand- Schuller –Christian disease3. Letterer-Siwe diseasePATHOGENESIS:characterized by proliferation of Langerhans cells and eosinophils along with other inflammatory cells. Langerhan cells are dendritic cells found in

mucosa, epidermis, lymph nodes that process and present antigens to T lymphocytes.

Overwelming allergenic response or viral etiology

CLINICAL PRESENTATIONAffects children and young adults. 3 forms exists1. Chronic localized or eosinophilic

granuloma….refers to solitary or multiple lesions bone lesions only

2. Chronic disseminated disease or Hand- Schuller- Christian disease …clinical triad of lytic bone lesions, exophthalmos and diabetes inspidus

3. Acute Disseminated Langerhans or Letterer- Siwe …affects infants, affecting skin, bones and internal organs esp lungs and liver.

4. Bone lesions involve the skulls, mandible, ribs and vertebrae. Jaw lesions produce pain, mobility

RADIOGRAPHIC APPEARANCE: Well defined punched out radiolucency floating teeth may be seen Involved teeth are vitalHISTOLOGY:They are diagnosed with immunohistochemical studies with S-100 and CD1a antigen.Langerhan cell contains cytoplasmic structures called Birbeck granulesTREATMENT:1. Accessible bone lesions are treated with curettage

and 5mm marginal resection2. Less accessible lesions are treated with radiotherapy3. Intralesional steroids are also employed in resolving

the lesions

GIANT CELL LESIONS

CENTRAL GIANT CELL GRANULOMA GIANT CELL TUMOR HYPERPARATHYROIDISM(BROWN’S TUMOR) CHERUBISM ANEURYSMAL BONE CYST

GIANT CELL LESIONS CENTRAL GIANT CELL GRANULOMA:Benign proliferation of fibroblasts and multinucleated giant cellsPATHOGENESIS:Proliferation of fibroblasts….cytokines release… of monocytes…transform into multinucleated giant Cells.. Osteoclasts begin to destroy boneOCCURENCE: 1. Found in young children and young adults, before

30 yrs2. Females most commonly affected3. Lesions occur anterior to 1st molar and cross the

midline

CLINICAL APPEARANCE Non aggressive , slowly expanding lesion Aggressive lesion , cortical expansion, root resorptionRADIOGRAPHICAL APPEARANCE:Unilocular/ multilocular radiolucency HISTOLOGY:Few to many giant cells in a background of FibroblastsTREATMENT:1. Surgical curettage with 15-20 % recurrence2. Intralesional steroids(weekly injections of

triamcinolone for 6 wks)3. Subcutaneous injection of calcitonin (giant cell have

calcitonin receptors)…inhibits of osteoclastogenesis4. Alpha-interferon is also given (will suppress the

angiogenic component of the lesion)

HYPERPARATHYROIDISM Overproduction of parathyroid hormone.1. Primary hyperparathyroidism…uncontrolled

production due to an adenoma, hyperplasia2. Secondary hyperparathyroidism..in response to

hypocalcemia due to chronic renal failurePATHOGENESIS:Excess PTH.. Stimulates osteoclast mediated bone resorption…focal bone lesion…brown’s tumor due to clinical appearance…erythrocyte extravasationRadiologically and histologically indistinguishable from GCG

HOW TO APPROACH SUCH PATIENTS Pay attention to clinical signs/ symptoms Groans, moans, stones and bones Serum calcium and phosphate, PTH, alkaline

phosphatase are done Raised PTH, raised serum Ca and raised ALP..

Primary hyperparathyroidism Raised PTH, Low serum Ca, Normal ALP, Renal

functions abnormal…secondary hyperparathyroidism

Normal PTH.. Giant cell granuloma TREATMENT: Treat the underlying cause.. Regression of lesion

CHERUBISM Autosomal dominant hereditary disorder. Genetic defect is in chromosome 4p16CLINICAL APPEARANCE: Children btw 2 and 5 yrs Begins as painless bilateral symmetric expansion

of the jaws Mand angle, ramus, retromolar area, max

tuberosity Max involvement may raise the orbital floor,

globes may be displaced upwards, resembling cherubes in renaissance paintings

RADIOGRAPHIC APPEARANCE: Multilocular radiolucency with thin cortices Premature exfoliation of primary teethTREATMENT:Lesions enlarge uptil puberty, then regressLater on, residual expansions can be contoured

OSTEOID OSTEOMA OSTEOBLASTOMA Less than 2cm Femur, tibia and phalanges Nocturnal pain relieved by

aspirin

Radiographically, mixed radiolucent-radiopaque pattern

Histologically irregular trabeculae of osteoid and immature bone

Treatment.. Conservative excision

Greater than 2 cm Vertebrae and bones

of cranium, mandible Pain is not nocturnal

and not relieved by aspirin

Same as osteoid osteoma

Same same

OSTEOMA Benign tumors of mature cortical and cancellous

bone Two types: peripheral osteoma;endosteal osteoma May arise in paranasal sinuses, skull and facial

bones Periosteal osteoma may present as slow growing

lesions Endosteal osteoma are asymptomatic. Solitary lesions or multiple in no for eg Gardeners

syndrome(multiple osteomas, intestinal polyps, fibromas skin, odontomes)