Odontogenic Tumors Assoc Professor Jan Laco MD Ph

Odontogenic Tumors Assoc. Professor Jan Laco, MD, Ph. D

Causes of jaw swelling • • Odontogenic cysts Odontogenic tumors Giant cell lesions Fibro-osseous lesions Primary (non-odontogenic) tumors of bone Metastatic neoplasms Chronic osteomyelitis

Odontogenic tumors • derived from epithelial, ectomesenchymal, mesenchymal elements of tooth forming apparatus • central (intraosseous) – maxillofacial skeleton • peripheral (extraosseous) – soft tissue - gingiva + alveolar mucosa • ethiology unknown, from some odontogenic cysts • RTG – uni-, multi-locular radiolucencies ~ cysts x radiopacities • !!! biopsy !!!

Odontogenic tumors • 1. Epithelial • ameloblastoma • squamous odontogenic tumor • calcifying epithelial odontogenic tumor • adenomatoid odontogenic tumor • • • 2. Epithelial+mesenchymal ameloblastic fibroma odontoma dentinogenic ghost cell tumor primordial odontogenic tumor

Odontogenic tumors • • 3. Mesenchymal odontogenic fibroma odontogenic myxoma cementoblastoma • 4. Carcinomas • ameloblastic carcinoma • primary intraosseous squamous cell carcinoma • clear cell odontogenic carcinoma • ghost cell odontogenic carcinoma • sclerosing odontogenic carcinoma • 5. Odontogenic carcinosarcoma • 6. Odontogenic sarcoma

Ameloblastoma • benign x locally aggressive • 1. solid / multicystic A (S/MA) – – – – – 2 nd most common odontogenic tumor M ~ F, peak 30 -50 Y; RTG: multilocular cystic radiolucency posterior mandible (70%) + posterior maxilla ( skull) spread through bone medullary spaces, cortex intact Mi: follicular / plexiform pattern + fibrous stroma islands of odontogenic epithelium (enamel organ-like) basaloid, granular, acanthomatous variants, kerato. A anastomosing strands recurrence (after 10 Y) – long term RTG follow-up !!! treatment: jaw resection with free margins (2 cm)

Ameloblastoma • 2. extra-osseous (peripheral) A – ~ S/MA x soft tissues over mandible, treat. : simple excision – older pts. , M : F … 1 : 2 • 3. unicystic A – – – 2 peaks – 16 Y (+ unerupted tooth) + 35 Y (NO uner. tooth) 5 -15% of all As, luminal x mural subvariants not so aggressive as S/MA diff. dg. from benign cysts !!! biopsy (! inflammation) treat. : luminal – simple excision x mural – acc. SMA • 4. metastasizing ameloblastoma – dg. in retrospect according to behaviour not histology!!; lung

Ameloblastic carcinoma • 1. primary – – rare, China posterior mandible Mi: malignant appearance A lung metastases • 2. secondary (intra-, extraosseous) – A (long lasting) AC – Mi: A + AC

Squamous odontogenic tumor • • benign x locally aggressive extremely rare M > F, ~ 40 Y mandible (from squamous nests in periodontal ligaments ? ) • Mi: well-differentiated squamous epithelium + fibrous stroma • dif. dg. : squamous cell carcinoma squamous nests in wall of jaw cyst - RTG

Calcifying epithelial odontogenic tumor • • • benign x locally aggressive „Pindborg´s tumor“ (1955) M ~ F, ~ 40 Y; RTG: radiolucency + opacity mandible (premolar/molar) Mi: sheets of pleomorphic epithelial cells x mitoses absent amyloid concentric calcifications • recurrence (20%) • treatment: according SMA • diff. dg. : poorly differentiated carcinoma

Adenomatoid odontogenic tumor • • benign, hamartoma ? ? ? M : F … 1 : 2; peak ~ 15 -30 Y anterior maxilla !!!; RTG: ~ odontogenic cyst sometimes around crown of unerupted tooth – dif. dg. : follicular (dentigerous) cyst • Mi: solid nodules – epithelial cells nests, tubular structures + eosinophilic material calcifications • treatment: enucleation

Ameloblastic fibroma • • • benign rare, ~ 15 Y posterior mandible; RTG: uni- / multilocular cyst Mi: ~ A + stroma ~ dental pulp treatment: enucleation diff. dg. : ameloblastoma – different treatment !!! • -------------------------- • Ameloblastic fibrodentinom/fibroodontoma – developmental stages of odontoma

Odontogenic sarcomas • 1. ameloblastic fibrosarcoma – malignant counterpart of ameloblastic fibroma • 2. ameloblastic fibrodentino-, fibroodonto-sarcoma – AFS + dentin / dentin + enamel – 1. + 2. no prognostic significance

Odontoma • • • true tumor (WHO), hamartoma ? ? ? most common odontogenic tumor children, adolescents treatment: enucleation 1. complex type – posterior mandible, encapsulated – Mi: haphazardly enamel + dentin + cementum • 2. compound type – anterior maxilla, encapsulated – numerous tooth-like structures (odontoids)

Dentinogenic ghost cell tumor • solid variant of calcifying odontogenic cyst • canine-first molar area • locally aggressive

Ghost cell odontogenic carcinoma • malignant counterpart of DGCT

Odontogenic fibroma • • benign, rare, somewhat controversial entity F : M … 3 : 1, ~ 40 Y mandible : maxilla … 6. 5 : 1 Mi: epithelium-rich x epithelium-poor odontogenic epithelium + fibrous stroma • dif. dg. : dental follicle - RTG

Odontogenic myxoma / myxofibroma • • • benign 3 rd most common odontogenic tumor F > M, ~ 30 Y molar mandible maxilla (maxillary sinus obliteration) spread through medullar bone space Mi: myxoid stroma + stellate cells recurrence (25%) !!! treatment: wide excision dif. dg. : dental pulp tissue

Cementoblastoma • • • benign M ~ F, ~ 20 Y first molar of mandible RTG: radiopaque mass + connection with tooth root !! Mi: acellular cementum-like material bordered by plump cells without atypia fibrovascular tissue • dif. dg. : osteoblastoma, osteosarcoma • recurrence !!! • treatment: enucleation + tooth extraction

Primary intraosseous squamous cell carcinoma • • • NO initial connection to oral mucosa solid from KOT from other odontogenic cysts metastases - LN and lungs

Clear cell odontogenic carcinoma • • WHO (1992) – benign x WHO (2005) - malignant F > M, ~ 60 Y mandible Mi: cells with clear cytoplasm + fibrous stroma aggressive behaviour, recurrence metastases – LN, lung, bone, … t(12; 22) … EWSR 1 -ATF 1

Melanotic neuroectodermal tumor of infancy • • = melanotic progonoma, retinal anlage tumor, … very rare (350 cases), neural crest ? ? ? infants (80% < 6 th month, 95% < 1 st year) F : M … 2 : 1 maxilla (70%), mandible (10%), skull (10%) rapidly growing pigmented mass, 3 -4 cm microscopy – small neuroblastic cells (granules), synaptophysin + – melanin-containing cells (melanosomes), CK, HMB 45 + • local recurrence + metastases (7%) to LN, liver, bone

Take home message • • • odontogenic tumors – rare x do exist NOT only ameloblastoma although benign x locally aggressive DON´T rely on RTG itself secondary inflammation may obscure the true nature of some lesions on microscopy • local recurrence (up to decades!) – long-term follow up !!! every lesion, incl. cysts, must be microscopically examined !!!