Odontogenic tumours II

Question 1

What tumours will be focused on here?

Answer 1

Epithelial with odontogenic mesenchyme
(mixed):
* Odontoma
* Ameloblastic fibroma
* Primordial odontogenic tumour
* Dentinogenic ghost cell tumour

Question 2

Name the Epithelial with odontogenic mesenchyme (mixed)?

Answer 2

• Odontoma
• Ameloblastic fibroma
• Primordial odontogenic tumour
• Dentinogenic ghost cell tumour

Question 3

Clinical presentation of ameloblastoma fibroma?

Answer 3

• Rare.
• Young adults and children.
• Slow growing painless swelling.
• Failure of permanent tooth to erupt.
• Posterior mandible.

Question 4

Radiographic appearance of ameloblastoma fibroma?

Answer 4

• Well defined radiolucency.
• Often in connection with unerupted teeth

Question 5

Histopathology of ameloblastoma fibroma?

Answer 5

• Mainly composed of immature cell rich tissue with fibroblasts
  possessing elongated cytoplasmic extensions resembling
  dental papilla.
• Strands and islands of epithelial cells distributed throughout.
  These show features of preameloblasts and stellate reticulum,
  and they resemble ameloblastoma.

Question 6

2 types of ameloblastoma fibroma?

Answer 6

• If dentine is present, the lesion is called ameloblastic
  fibrodentinoma, and if enamel is present as well, the
  tumour is called ameloblastic fibro-odontoma. Both are
  thought to be odontomes.

Question 7

Management of ameloblastoma fibroma?

Answer 7

• Enucleation and curettage.
• Recurrence may occur but is readily curable.
• Rarely, may undergo progressive malignant change to
  ameloblastic fibrosarcoma.

Question 8

Clinical presentation of dentinogenic ghost cell tumour?

Answer 8

• Locally invasive.
• Mainly intra-osseous but peripheral lesions are also
  reported.
• Could be asymptomatic.
• Bony expansion and cortical bone destruction with
  extension into soft tissues.
• Adjacent teeth may be displaced and mobile.

Question 9

Radiographic appearance of dentingenic ghost cell tumour?

Answer 9

• Mixed radiolucent and radiopaque appearance due to
  calcification.
• Most are unilocular with well- defined borders.
• Resorption of adjacent teeth.

Question 10

Differential diagnosis?

Answer 10

Pindborg tumour

Unicystic ameloblastoma

Dentigerous cyst

Question 11

Histopathology of dentinogenic ghost cell tumour?

Answer 11

• Tumour islands that resemble ameloblastoma.
• Ghost cells (individual cells or islands) with keratinization.
• Some ghost cells undergo calcification and dysplastic
  dentin may be formed.
• Invasion of medullary spaces (similar to ameloblastoma).

Question 12

Management of dentinigenic ghost cell tumour?

Answer 12

• Local resection, especially if the tumour margins are poorly
  defined.
• Enucleation or conservative excision may be appropriate
  for peripheral (extraosseous)tumours.
• Rare malignant transformation to dentinogenic ghost cell carcinoma.

Need clear margin as it invades medullary bone