Ameloblastoma
Epidemiology:
Common sites:
- molar-ramus of the mandible
Gross features:
- commonly cystic
- may be solid
Histologic features:
- similar appearance
to basal cell carcinoma
- nests, strands,
and networks of epithelium
- budding of epithelium
from these nests and strands
- cystic areas
sometimes
- cyst lining may
be non-diagnostic (ex. stratified squamous)
- well-differentiated
palisading cells at the periphery
- polarized away
from the basement membrane
- subnuclear vacuolization often
- cells above the
basal layer are “stellate reticulum”-like
- stellate shaped cells
- discohesive appearance
- no solid tissue
formation (no ectomesenchymal differentiation)
(no enamel and dentin)
- locally invasive
- desmoplastic variant (sclerotic variant):
- majority of tumour consisting of islands and cords appearing to
be compressed by sclerotic / desmoplastic stroma
- rare malignant variant:
- may show
cytological atypia
Immunophenotype:
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Marker:
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Sensitivity:
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Specificity:
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Molecular features:
Other features:
- benign course
usually
- solid lesions
have a higher recurrence rate
- slow destructive
growth
- radiology:
- well-defined unilocular or multilocular
lucencies
References:
- Robbins 2005
- Mod Surg Path 2003