Ameloblastoma

Question 1

What is the origin of ameloblastoma

Answer 1

Rests of Serres

Question 2

What are the rests of serres

Answer 2

Rests of seres are epithelial remnants in fibrous gingival tissue

Question 3

What is a key component of histology in ameloblastoma

Answer 3

Reverse polarity of nuclei pathognomonic is a key part of ameloblastoma histology.

Question 4

Name the 6 histologic subtypes;

Answer 4

• Follicular
• Plexiform (most common)
• Granular
• Acanthomatous
• Desmoplastic
• Basal Cell

Question 5

What is the most common histologic subtype of ameloblastoma?

Answer 5

Plexiform

Question 6

What is the histology of folicular ameloblastoma?

Answer 6

Palisaded ameloblastlike cells and inner zone of triangular-shaped cells resembling stellate reticulum in bell stage.

Question 7

What is the common appearnce of plexiform ameloblastoma

Answer 7

epithelium that proliferates in a fisnhet pattern

Question 8

What is the radiographic appearnce ofameloblastoma

Answer 8

Radiolucency with multilocularated-soap bubble appearance except for desmoplastic subtype which is radiopaque due to collagenized stroma,; root resoprtion is common

Question 9

What is the clinical presenation of ameloblastoma?

Answer 9

Solid and/or cystic, buccolingual expansion, peripheral painless warty appearance

Question 10

What is the location of ameloblastoma

Answer 10

Posterior mandible in desmoplastic, anterior maxilla in peripheral

Question 11

What is the treatment and recurrence rate of solid or multicystic ameloblastoma?

Answer 11

Question 12

What decade does solid or mulitcystic ameloblastoma usually occur?

Answer 12

4th decade

Question 13

What is the treatment and recurrence rate of unicystic ameloblastoma?

Answer 13

Question 14

What decade do unicystic subtypes typically occur?

Answer 14

3rd decade

Question 15

What is the treatment and recurrence rate of peripheral ameloblastoma?

What decade of life does it occur?

Answer 15

6th decade of life, excision, with no recurrence

Question 16

T/F: Ameloblastoma’s incidence exceeds that of all other odontogenic tumors

Answer 16

True

Question 17

The tumors of course arise from the Rests of seres but also can say they arise from…

Answer 17

Rests of dental lamina, a developing enamel organ, the epithelial lining of an adontogenic cysts, or the basal cells of the oral mucosa

Question 18

Three different variants of ameloblastoma

Question 19

Which variant of ameloblastoma is most common?

Answer 19

Solid/multicystic which is 92% of the cases

Question 20

Describe multicystic or solid ameloblastomas for me (

Answer 20

1. About 85% occur in the posterior mandible near the ramus or mollar
2. 15% occur in the posterior maxilla
3. There is a painless expansion of the jaws with neursensory changes being uncommon
4. Thre can be tremendous facil disfigurment.
5. Most commmon radiographic feature is a multilocular radiolucency with buccal/lingual cortical expansion to the point of perforation.
6. Resorption of roots is common

Question 21

What is the stellate reticulum

Answer 21

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 glycosaminoglycans are produced, water is drawn in between the cells, stretching them apart.
• As they are moved further away from one another, the stellate reticular cells maintain contact with one another through desmosomes, resulting in their unique appearance.
• The stellate reticulum is lost after the first layer of enamel is laid down. This brings cells in the inner enamel epithelium closer to blood vessels at the periphery

Question 22

Describe a picture of the stellate reticulum

Answer 22

Question 23

Describe a diagram of the stellate reticulum.

Answer 23

Question 24

How do the different types of multicycstic ameloblastoma (follicular and plexiform) relate to the stellate reticulum.

Answer 24

1. Follicular in which the stellate reticulum is located within the center of the odontogenic island
2. Plexiform-stellate reticulumis located outside of the odontogenic rests

Question 25

What is the histological pattern of acanthomatous multicystic/solid ameloblastoma?

Answer 25

Squamous differentiation of the odontogenic epithelium is present

Question 26

What is the histological pattern of granular cell multicystic/solid ameloblastoma?

Answer 26

Tumor islands exhibit cells that demonstrate abundant granular eosinophilic cytoplasm Eosin is a bright-pink protein based dye that will therefore react or 'stain' proteins suspended in the cytoplasm of cells as well as extracellular proteins such as collagen. Thus, we get the term 'eosinophilic cytoplasm'. A more inclusive term, 'Acidophilic', refers to all cellular tissues which react to an acid dye. The eosinophil is a specialized cell of the immune system. This proinflammatory white blood cell generally has a nucleus with two lobes (bilobed) and cytoplasm filled with approximately 200 large granules containing enzymes and proteins with different (known and unknown) functions.

Question 27

What is the histological pattern of desmoplastic multicystic/solid ameloblastoma?

Answer 27

Extremely dense collagenized stronga tha tsupports the tumor

Question 28

What is the histological pattern of basal cell multicystic/solid ameloblastoma?

Answer 28

nests of uniform basaloid cells are presents with a strong resemblance to basal cell carcinoma. In this stellate reticulum is not present in the central portion o fthe nests.

Question 29

What makes desmoplastic ameloblastoma unique radiographically?

Answer 29

It is generally not radilucent tumor due to the high content of collagenized stroma.

Question 30

What pathogenetic finding is associated with the recurrence rate of ameloblastoma

Answer 30

Highest number of PNCA-positive cells It aslso includes an overexpression of BCL2 and BCLX as well as the expression of IL-1 and IL-6 Multicystic/solid ameloblastomas have higher PNCA positive cells than unicystic.

Question 31

T/F: There is no concensus on the biolgoic behavior of ameloblastoma

Answer 31

True

Question 32

Why does the actual margin of ameloblastoma usually extend beyond its apparent radiographic or clinical margin?

Answer 32

The solid of multicystic ameloblastoma tends to infiltrate between intact cancellous bone trabeculae at the periphery of the tumor before bone resorption becomes radiographically evident so it usually extends beyond that.

Question 33

Due to the agressive nature of solid/multicystic ameloblastoma, what should the resection margin be?

Answer 33

It should be 1.0 cm with interaoperative specimen radiographs.

Question 34

Does an anatomical barrier need to be sacrificed with solid/multicystic ameloblastomas?

Answer 34

Yes, one uninvolved surrounding anatomic barrier should be sacrificed on the periphery of the specimen.

Question 35

Is ameloblastoma malignant or benign?

Answer 35

Some would say malignant because it is locally invasive and prone to reoccur. It has been compared to basal cell carcinoma which is slow growin, infiltrative, capable of greater destuction of soft tissue and bone, recurrent when not completely eradicated, capable of infading vital structures, seldom metastatic but capable of metastasis, presenting a numbe rof histological patterns

Question 36

When do unicystic ameloblastomas typically form?

Answer 36

2nd decade, 50% happen around then and the average age is reported at 22.1

Question 37

Why does unicystic ameloblastoma mimic a dentigerous cysts

Answer 37

Because it appears as a unilocular radiolucency is the posterior mandible

Question 38

One of the histological variants of unicystic ameloblastoma is a luminal unicystic ameloblastoma Describe is histologiclly.

Answer 38

Confined to the luminal surface of the cyst. Consits of a fibrous cyst wall with a lining that consists totally or partially of ameloblastic epithelium.

Question 39

One of the histological variants of unicystic ameloblastoma is a intraluminal unicystic ameloblastoma Describe is histologiclly.

Answer 39

Contains one or more nodules of ameloblastoma projecting from the cystic lining into the lumen of the cyst. These nodules may be relatively small or largely fill the cystic lumen and are noted to show a plexiform pattern that resemles the plexiform pattern seen in conventional ameloblastomas. These are often called plexiform unicystic ameloblastomas

Question 40

One of the histological variants of unicystic ameloblastoma is a mural ameloblastoma Describe is histologiclly.

Answer 40

The fibrous wall of the cyst is infiltrated by typical follicular or plexiform ameloblastoma. The extent and depth may vary considerably

Question 41

Walk me through an algorithm of a large unicystic lesion with

Answer 41

Question 42

Luminal Intraluminal Mural Treatment options

Answer 42

Luminal and intraluminal are usually enuclation and curretage Mural is resection

Question 43

When to resect a unicystic ameloblastoma

Answer 43

1-Recurrent unicystic ameloblastoma after failed enuclation and curretage 2-mural amelblastoma because it is more aggressive than luminal and intraluminal owing to the presence of the tumor in the cyst wall and its proximity to surrounding bone. 3-Management of a large tumor where enucleation and curretage would not be effective.

Question 44

How do peripheral ameloblastomas present?

Answer 44

tumors present as non-ulcerated sessile or pedunculated gingival lesions. Most are smaller than 1.5 cm and usually occur over a wide age range.

Question 45

Peripheral ameloblastomas and malignant transformation. Common or rare?

Answer 45

Rare