Odontogenic tumours II

Question 1

What tumours will be focused on here?

Answer 1

BENIGN ODONTOGENIC TUMOURS

Epithelial without odontogenic
mesenchyme:
* Ameloblastoma (all types)
* Squamous odontogenic tumour
* Calcifying epithelial odontogenic tumour
* Adenomatoid odontogenic tumour

Question 2

Clinical presentataion of squamous odontogenic tumours?

Answer 2

Rare, between the roots of the teeth.

Question 3

Radiographic appearance of squamous odontogenic tumour?

Answer 3

• Well circumscribed unilocular triangular shaped radiolucency.
• Larger lesions can be multilocular.

Question 4

Differential diagnosis?

Answer 4

Lateral Radicular cyst

Paradadicular cysts

Question 5

Histopathology of squamous odontogenic tumour?

Answer 5

• Irregularly shaped islands of well differentiated squamous
  epithelium sometimes with peripheral cuboidal cells.

Question 6

Pathogeneess of squamous odontogenic tumours?

Answer 6

• Rests of Malassez.

Question 7

Calcifying epithelial odontogenic tumour (pindborg tumour)

Answer 7

• Locally invasive neoplasm
• Amyloid material that may become calcified.
• Rare accounting for 1% of all odontogenic tumours
  occurring in patients between 20 and 60 years (mean around
  40 years).
• Most cases are intraosseous but there is an extraosseous
  variant.
• Mandibular premolar area is the most common site.
• Clinically, it is an asymptomatic, slow- growing mass
  expanding the jaw.
• Extraosseous lesions are firm, painless masses.

Question 8

Radiographic appearance of Calcifying epithelial odontogenic tumour (pindborg tumour)?

Answer 8

• Mixed radiolucent and radiopaque lesion
• Unilocular or multilocular.
• Often associated with an unerupted tooth

Question 9

What is this?

Answer 9

Could be mistaken for a Osteosarcoma

It is a pindborg tumour

Question 10

Histopathology of pindborg tumour?

Answer 10

• Sheets and islands of polyhedral epithelial cells,
  eosinophilic cytoplasm.
• Clear cells can make up a big proportion of the tumour.
• Pleomorphic nuclei with common large nuclei.

Calcified myeloid not cementicles!

Question 10

What does Amyloid?

Answer 10

Acidic get stained

Zynophilic

Question 11

Manage to of pindborg tumour?

Answer 11

• Local excision with a margin of normal tissue.
• Recurrence in ~ 20% of cases and is more frequent when a
  clear cell component is present.
• Rare malignant variants.

Question 12

More clear cells means what?

Answer 12

More lies to reoccur - more aggressive

Question 13

Clinical presentation of adenomatid odontogenic tumour?

Answer 13

• Second and third decades of life.
• Benign tumour or hamartoma.
• Intraosseous, more common in maxilla.
• Rare peripheral type, mostly in anterior maxillary gingiva.
• Associated with unerupted permanent teeth, especially
  maxillary canines.
• Asymptomatic but may cause jaw expansion and
  displacement of adjacent teeth.

Question 14

Most common location of adenomatid odontogenic tumour?

Answer 14

Impacted maxillary canines

Question 15

Radiographic appearance of adenomatoid odontogenic tumour?

Answer 15

• well defined radiolucency
  with corticated outline.
• Unerupted teeth (DD
  dentigerous cyst).

Question 16

Differentiatial diagnosis of adenomatoid odontogenic tumour?

Answer 16

Dentigerous cyst

Unicystic ameloblastoma

Question 17

Histopathology of adenomatid odontogeni tumour?

Answer 17

• Variably sized, solid nodules of cuboidal or columnar cells
  of odontogenic epithelium forming nests with minimal stromal
  connective tissue.
• Tubular duct- like spaces lined by a single row of columnar
  epithelial cells, with the nuclei polarized away from the
  luminal surface, are characteristic.
• Nodules consisting of polyhedral, eosinophilic epithelial
  cells of squamous appearance are also seen.
• Globules of amorphous amyloid- like material and calcified
  osteodentine may be found.

Question 18

Management of Adenomatoid Odontogenic Tumour?

Answer 18

• Enucleation with removal of the unerupted tooth if present.
• Conservative local excision.