What is the most common odontogenic and benign tumor of jaw?
ameloblastoma: posterior mandible, 30-40s, m>f
painless swelling covered by normal mucosa
What is radiographic appearance of ameloblastoma?
variable: unilocular early w remnants of normal bone -> mixed density & septa, multilocular later-> soap bubble
growth: locally aggressive, expansive, displace tooth, may resorb roots
recurrence: high, dangerous max
treatment: aggressive surgery
variant: mural on cyst walls
What is the difference in radiographic presentations of septa in ameloblastoma ,central giant cell granuloma and odontogenic myxoma?
CGCG: multilocular wispy thin septa
ameloblastoma: course septations
odontogenic myxoma: linear
What are the histo findings of ameloblastoma?
follicular, adnexal derived similar to basal cell carcinoma
odd shaped islands with peripheral cells palisaded
may have bone reminants
Islands of cells with palisaded nuclei that have reverse polarization.
Reverse polarization of nuclei: nuclei distant from the basement membrane/nuclei at pole opposite of basement membrane.
Palisaded nuclei = picket fence appearance; columnar-shaped nuclei with long axis perpendicular to the basement membrane.
Subnuclear vacuolization in palisading cell - vacuoles at the basement membrane aspect.
Loose stroma around the islands of cells.
Star-like cells at the centre of the islands of cells (stellate reticulum).
What is stellate reticulum?
The stellate reticulum is a group of cells located in the center of the enamel organ of a developing tooth. These cells are star shaped and synthesize glycosaminoglycans. As glycosamingoglycans are produced, water is drawn in between the cells and stretch them apart. As they are moved further away from one another, the stellate reticulum maintain contact with one another through desmosomes, resulting in their unique appearance. stellate reticulum is lost after the first layer of enamel is laid down. This brings cells in inner enamel epithelium closer to blood vessels at the periphery