Odontogenic Tumours Flashcards
What are the 3 classifications of odontogenic tumours?
Epithelial
Mesenchymal
Mixed (epithelium & mesenchyme)- often have dental hard tissues bound within the tumours
BASED ON ORIGIN
What are the only types of tumours that can have dentine/enamel formation?
Why?
Mixed tumours
Due to concept of induction (cannot have enamel without the place of dentine first)
What is an ameloblastoma?
Benign epithelial tumour
Locally destructive but slow-growing
Typically painless
What different radiological appearances can an ameloblastoma have?
Multicystic or unicystic
Well defined, corticated or scalloped in the multicystic variations
Primarily radiolucent
Displacement of teeth or IAN can be present
Thinning of bony cortices
‘Knife edge’ external root resorption of teeth (clean cut side of the tooth)
Characteristic growth pattern- all directions equally
What 3 histological types of ameloblastoma can you get?
Follicular
Plexiform
Desmoplastic
What does the histology of a follicular ameloblastoma look like?
Islands present within a fibrous tissue background
Islands are bordered by columnar cells with a dark staining nucleus
Cystic changes within the follicles
Stellate reticulum like cells
No connective tissue capsule
What does the histology of Plexiform ameloblastoma look like?
Ameloblast-like cells arranged in strands with small amount of stellate reticulum like tissue in between
No connective tissue capsule
What feature of all types of ameloblastoma allows it to easily infiltrate into the jaw bones?
No connective tissue capsule present
Leads to high recurrence rates
What is the management of ameloblastoma?
Surgical resection with margin taken away (1cm of normal bone around the pathology)
What is an Adenomatoid Odontogenic Tumour?
Benign epithelial tumour
Unilocular radiolucency with internal calcifications around the crown of unerupted maxillary canine - is the classic presentation
What is the presentation of adenomatoid odontogenic tumour?
75% associated with an unerupted tooth
Impedes eruption
Unilocular radiolucency
Majority have internal calcifications/radiopacities
Margins well-defined & corticated/sclerotic
May displace adjacent structures but external root resorption is rare
What is the histology of adenomatoid odontogenic tumours?
Epithelial origin
Sometimes a degree of calcification
Well developed fibrous tissue capsule surrounding the cells- makes removal easier
Low recurrence
What is a calcifying epithelial odontogenic tumour (CEOT)
Benign epithelial tumour
What is the presentation of calcifying epithelial odontogenic tumours?
Slow-growing but can become large
Half are associated with an unerupted tooth
Radiolucency often with internal radiopacities
Can be
–unilocular/multilocular
–well-defined/poorly defined
What is an odontogenic myxoma?
Benign mesenchymal tumour
What is the presentation of an odontogenic myxoma?
Well-defined radiolucency +/- thin corticated margin
Smaller lesions are unilocular
Larger lesions are multilocular with scalloped margins ‘soap bubble appearance’
Slow growth along bone before causing notable bucco-lingual expansion
External root resorption rare
What is the histology of odontogenic myxoma?
Loose myxoid tissue with stellate cells
May contain islands of inactive odontogenic epithelium
No fibrous tissue capsule -> locally invasive (infiltrates into adjacent bone)
Mesenchymal in origin
What is an odontoma?
Benign mixed tumour
Malformation of dental tissue
–enamel, dentine, cementum & pulp
What are the types of odontoma?
Compound
Complex
What is a compound odontoma?
Ordered dental structures
-may appear as multiple mini teeth (i.e. denticles)
What is a complex odontoma?
Disorganised mass of dental tissues
