odontogenic tumors Flashcards
what is ameloblastoma
it is a tumor of odontogenic origin and arise from rests of dental lamina or developing enamel organ/ epithelial lining of odontogenic cyst / basal cells of oral mucosa
mutations in BRAFV 600E gene
what are the three types of Ameloblastoma
- solid/ multicystic/ conventional
- unicystic
- peripheral /extraosseous
cf of conventional ameloblastoma
- 30 to 70 yrs
- no sex predilection
- mandible(molar- angle- ramus area) > maxilla
- painless swelling or jaw expansion with facial asymmetry
- large lesions have mobile teeth, pain and parasthesia
- they can erode cortical bone
radiographic features of conv amelo
- multilocular radiolucent lesion, with a soap bubble appearance/ honey comb
- buccal and lingual cortical plate expansion
- root resorption
- some lesions may be unilocular having irregular scalloping
which histopathologic form of ameloblastoma does not have characteristic features of other types
desmoplastic
name the histopathological variants of multicystic ameloblastoma
- follicular
- plexiform
- acanthomatous
- granular cell
- desmoplastic
- basal cell type
histopathology of follicular pattern
- most common
- islands of epithelium within a fibrous stroma
- epithelial nests have a core of loosely arranged angular cells resembling stellate reticulum
- a single layer of tall columnar cells with reversed polarity surround the core
- cysts could be microcysts or large cysts.
histopath of plexiform pattern
- long anastomosing cords of epithelium bounded by columnar cells and surrounded by loose columnar cells
- duct like structures may be formed in the loose vascular stroma
acanthomatous pattern
- squamous metaplasia+ keratin formation in central portion of epithelial islands of follicular ameloblastoma
- dd could be SCC
granular cell pattern
lesionsla epithelial cells transform into granular cells
these cells have granules that resemble lysosomes and are considered to be age change
desmoplastic pattern
has small islands and cords of epithelium with dense collagenised stroma
TGF-beta is produced
basal cell pattern
nests of uniform basaloid cells
similar to BCC
no stellate reticulum in centre
periphery has cuboidal cells
treatment of multicystic amelo
enucleation
curettage (RR = 50 -60%)
en bloc resection
Followed by peripheral ostectomy
cf of unicystic ameloblastoma
- 2nd decade
- mandible(post regions)
- small ones are painless
- also seen in periapical regions and edentulous patients
radiological geatures of unicystic
- circumscribed radiolucency that surrounds crown of unerupted molar
HP of uni amelo
3 variants are
- luminal
- intraluminal
- mural
LUMINAL
- tumor is confined to luminal surface of cyst
-it has fibrous cyst wall + layer of ameloblastic epithelium
- this layer has columnar cell with hyperchromatic nuclei having reversed polarity and basilar cytoplasmic vacuolisation
- upper cells are loosely like stellate reticulum
INTrALUMINAL
- one or more nodules project into lumen from the lining
- nodules may be big/small
- may hv plexiform pattern
MURAL
- cyst wall is infiltrated by follicular / plexiform ameloblastoma
treatment of unicystic
enucleation
10-20% RR
DD of unicystic
dentigerous cysts
okc
cf of inraosseous amleoblastoma
- painless non ulcerated
- less than 1.5cm
- middle aged
- posterior gingiva and alv mucosa
- could erode bone
HP of intraoss ameloblastoma
- islands of ameloblastic epi in the lamina propria
- connected to basal layer
- peripheral cells reversed polarity
DD of intaoos ameloblastoma
pyogenic granuloma
fibroma
