Oral Med: Ameloblastoma

Question 1

Define Ameloblastoma

Answer 1

Ameloblastoma is a neoplasm of odontogenic epithelium, principally of enamel organ-type tissue that has not undergone differentiation to the point of hard tissue formation.

Question 2

Classify Ameloblastoma

Answer 2

Multicystic and Unicystic

Multicystic include Follicular, Plexiform, desmoplastic and metastasising

Question 3

How would you manage ameloblastoma?

Answer 3

Imaging to assess the extent of tumour, a biopsy to assess the histological nature. If unicystic enucleate, All other types resect with a 1cm margin. Enucleation may be offered but carries a higher risk of recurrence.

Question 4

What genetic mutations are seen in Ameloblastoma

Answer 4

BRAF mutation at V600 activates the MAP Kinase pathway; SMO mutations activate the sonic hedgehog pathway.

Question 5

Describe the histology of ameloblastomas

Answer 5

Follicular AB shows a line of tall columnar cells with reverse polarity surrounding cells that appear to have a stellate reticulum. Plexiform AB has ameloblastic cells pulled out into long strands or sheets.

Question 6

What is the differential for soap bubble-like radiolucency.

Answer 6

Ameloblastoma, Odontogenic Keratocyst, Odontogenic Myxoma and Central Giant Cell Granuloma.

Question 7

What is the recurrence rate for unicystic ameloblastoma

Answer 7

10%

Question 8

what histological feature can predict a high rate of recurrence

Answer 8

Extension of ameloblastoma cells into the medullary spaces

Question 9

At what sites do ameloblastomas occur?

Answer 9

80% ameloblastomas occur in the mandible. 75% occur in the pstdfdvd

Question 10

Name a condition that produces a soap bubble or honey comb appearance in the posterior mandible, that resembles a normal dental follicle histologically.

Answer 10

Odontogenic Myxoma

Question 11

How do Odontogenic Myxomas grow

Answer 11

They grow by deposition of ground substance by fibroblasts rather than tissue growth.