ODONTOGENIC TUMOURS-AMELOBLASTOMA

2. ODONTOGENIC TUMORS
- AMELOBLASTOMA -
Dr.MANOJ KUMAR

3. INTRODUCTION
The permutation of
different cells of
different origin makes
odontogenic tumors a
highly complicated
group of lesions

4. EPITHELIAL ODONTOGENIC TUMORS
1. Minimal inductive change in CT
 Ameloblastoma.
 CEOT (Pindborg’s)
 AOT
2. Extensive inductive changes in connective tissue
 Ameloblastic fibroma
 Ameloblastic fibro-odontoma
 Odoto- Ameloblastoma
 Odontoma – Complex
Compound

5. MESODERMAL ODONTOGENIC TUMOURS
 Central odontogenic fibroma
 Odontogenic myxoma
 Cementoma –
• Periapical cemental dysplasia
• Cementifying fibroma
• Benign cementoblastoma
 Dentinoma

6. Malignant odontogenic tumors
– Odontogenic carcinoma
• Primary intraosseous carcinoma
• Malignant Ameloblastoma
– Odontogenic Sarcoma
• Ameloblastic Fibrosarcoma
• Ameloblastic Odontosarcoma

7. AMELOBLASTOMA

8. WHO (1992)
“Is a true neoplasm of enamel organ like
tissue which does not undergo
differentiation to the point of enamel
formation”

9. Robinson described it as
A tumour that is usually unicentric,
nonfunctional intermittent in growth
anatomically benign clinically persistent

10. Synonyms :
 Admantinoma
 Multilocular cyst
 Admantoblastoma
 Eve’s Diesease

11. History :
• CUZACK (1827)- First Recognized
• FALKSON (1879) – Description
• MALASSEZ (1885) – Admantinoma
• IVY &CHURCHILL (1934) – Ameloblastoma
• Unicystic ameloblastoma – Robinson and
Martinez in 1977

12. ORIGIN
• Cell rests of enamel organ
– Dental lamina remnants
– Hertwig’s sheath
– Rests of malassez
• Epithelium of Odontogenic cysts (Dentigerous cyst &
Odontomas)
• Disturbances in developing enamel organ.
• Heterotropic epithelium in other parts of the body,
especially the Pituitary Gland.
• Basal cells of oral epithelium.

13. extra osseous
• Dental lamina
ameloblast
• Oral epithelium

14. Incidence
 1% of oral tumors
 18-20% of odontogenic
tumors

15. Clinical features
 20-50 years
 Number of cases reported in
children
 Youngest reported one month old
 Oldest 98 yrs

16.  Frequent in
mandible than
maxilla
 3:1

17. Signs & symptoms
 Asymptomatic
 Asymmetry
 Slow growing – non
tender
 Later stages pain

18.  Secondary infection
 Ulceration
 Egg shell crackling
 Extra osseous Small nodule

19. Classification
Robinson and Martinez 1977
Anatomic site
1. Central /intraosseous
i. Multicystic/Conventional
ii. Unicystic
iii.solid
2. Peripheral/ extra osseous

20. Radiological features
• Numerous well defined radioluscency of varying
diameter
• Honey comb
• Soap bubble appearance
• Unicystic radiolucent lesion indistinguishable
with cysts

23. Ameloblastoma
With in medullary cavity
Scalloping of inner cortex
Pressure erosion
Shell remains

25. C T SCAN

27.  When maxillary sinus involved
 Cloudiness of sinus
 Destruction of wall
 Unicystic in maxilla

28. Histopathology
• Follicular
• Plexiform
• Acanthomatous
• Granular cell
• Desmoplastic
• Basal cell type

29. Follicular

30. Plexiform

31. Acanthomatous

32. Granular cell

33. Desmoplastic

34. Basal cell

35. Unicystic ameloblastoma
Ackerman in 1988
1. Type-I Luminal (consisted of unilocular cystic lesions lined by
epithelium exhibiting features of ameloblastoma).
1. Type-II Intra luminal (showed epithelial nodules arising from
the cystic lining and projecting into the cyst lumen. These
nodules comprised epithelium with a plexiform or follicular
pattern resembling that seen in intraosseous ameloblastoma.).
1. Type-III Mural ameloblastoma (characterized by the presence of
invasive islands of ameloblastomatous epithelium in the
connective tissue wall of the cyst, and these islands may or may
not be connected to the cyst lining)

37. Mural Ameloblastoma

39. Peripheral ameloblastoma
• Peripheral ameloblastoma (PA) is a rare odontogenic tumor that
accounts for 1% for all ameloblastomas.
• Kuri first reported PA in 1911
• In 1959, Stanley and Krogh defined the clinical and histopathologic
characteristics.
• The strict definition of PA according to Buchner and Scuibba (1987)
excludes lesions in extragingival locations.

40. The etiology of PA is unclear. The tumor can derive from the extraosseous
epithelial remnants of the dental lamina or from the basal cell layer of the
oral mucosa, which is believed to have odontogenic potential

41. • The differential diagnosis usually includes
– Pyogenic granuloma, peripheral
– Giant cell granuloma,
– Peripheral odontogenic fibroma,
– Peripheral ossifying fibroma,
– Papilloma,
– Epulis.
• Only four cases of malignant PA have been
reported to date.

42. Pitutary ameloblastoma
• Craniopharyngioma
• Rathke’s pouch tumor

43. DIFFERENTIAL DIAGNOSIS
–Multilocular cyst
Dentigerous cyst
Odontogenic kerato cyst
–Giant cell granuloma, cherubism
–Brown’s tumor
–Central hemangioma
–Odontogenic myxoma

44. Treatment
–Behavior and potential of tumor
–Growth characteristics
–Anatomic site
–Clinical extent
–Size of tumor
–Histologic pattern

46. Less than complete
excision is equivalent to
planned recurrence

47. General principles

48. 1. Definitive & offer best cure
2. Curettage and enucleation – recurrence
3. Curettage condemned
4. Cancellous bone – readily infiltrated
resorbed by tumor
5. Dense cortical bone - temporary barriers

49.  A safe margin of uninvolved bone is 2 cm for
solid and multicystic lesion
 1-1.5 for unicystic and peripheral lesions
 Resorption of cortical bone – periosteum
involved – surrounding soft tissue and muscle
 Post treatment follow up 15-20 yrs

50. Specific principles

51. Intra osseous solid / multi cystic
ameloblastoma
 Excision of lesion
 Enbloc resection -- without continuity
defect
 Enbloc resection– with continuity
defect

54.  Inferior alveolar nerve if in lesion- sacrificed
 Nerve grafting best to perform at time of
resection
 Resection should be exterior to tumor
involving plane

55.  A thin inferior border preserved may fracture-
reconstruction plate
 <1 cm not practical
 Resection with sharp cutting instrument
 Grinding with bur – not allow histologic
evaluation at tumor bone interface

56. Confirmed by frozen section
 Immediate reconstruction
Delayed reconstruction

57. • Autogenous free bone graft
• Allogenic bone with reconstruction plate
• Platelet rich plasma mixed into a cortical/
cancellous bone graft
• If sufficient soft tissue not available -
vascularized composite pedicle graft
• Delayed reconstruction : reconstruction plate to
maintain resection space

58. An anatomic classification of maxillary ameloblastoma as
an aid to surgical treatment
I T Jackson and P P Callan
J Cranio Maxillofac Surg 1996;24; 230
Group I tumors confined to maxilla with out involving orbital floor
- Partial maxillectomy
Group II tumor involving orbital floor not the periorbital tissue
- total maxillectomy
Group III tumor involving orbital contents
- total maxillectomy with orbital excentration
Group IV tumor involving skull base
- total maxillectomy with orbital excentration and anterior
skull base resection

59. Unicystic ameloblastoma
 Initial diagnosis
 Dentigerous cyst or OKC
 Enucleation or marsupialization?
 Careful assessment
 Biopsy may not confirm
 Physical basis cleavage plane
 Microscopic section R without CD or
R with CD

60. Peripheral ameloblastoma
 Enmass excision
 With overlying mucosa periosteum
alveolar bone and adjacent teeth
 1-1.5 resection margin

61. Cautery
 Chemical agents
 Electro cautery
 Cryotherapy

62. Carnoy’ solution
• Culter & Zollinger 1933 described as a
sclerozing agent for the treatment of cysts and
fistulae, and remains in use today as a fixative
Composition
i. Glacial acetic acid
ii. Absolute alcohol
iii. Chloroform
iv. Ferric chloride
• Depth of penetration 1.5-1.8 mm

63. Unicystic ameloblastoma – use of Carnoy’s
solution after enucleation
P K Lee N Samman
Int J Oral Maxillofac Surg 2004; 33 ; 263-7

64. Cryotherapy
 Adjunct to curettage
 Devitalize the tissue with liquid nitrogen
Depth 1.5 cm
 Jaw can be frozen the entire thickness
 Complication sequestration and pathologic
fracture
 Transient anesthesia

65. Management of mandibular ameloblastoma
treatment algorithm
Daniel E Sampson, M. Anthony Pogrel
J Oral Maxfac Surg 57; 1074-77 :1999
• Curettage recurrence
• Curettage with cryotherapy
• Confined to bone respond well to cryotherapy
• Soft tissue extension – necrosis
• Pathologic fracture – secondary to necrosis and
demineralization of bone
• Immediate bone grafting

66. Radiotherapy
 Inoperable cases
 Invasion into cranium
 Primarily intraosseous- resistant
 Extra osseous ameloblastoma - reduced
 Possible osteoradionecrosis
 Cause of metastasis

67. MALIGNANT BEHAVIOUR AND META STASIS
• Malignant ameloblastoma is a histologically well-
differentiated, benign appearing ameloblastoma with
metastatic disease histologically identical to the primary
tumor.
• Ameloblastic carcinoma is an ameloblastoma with
histological malignant transformation in the primary
lesion with or without metastatic disease.

68. • Metastases from malignant ameloblastomas have been
reported in the
– lung (75%),
– cervical lymph nodes (15%),
– spine (15%), and,
– less frequently, in the liver, skull, diaphragm, and brain.
• Markedly aggressive clinical course
• Quiescent chronicity
• After irradiation

69. Pulmonary metastasis of ameloblastoma
James M Henderson, J R Sonnet
J. Oral Surg Oral Path Oral Med Oral Radiol Endod;88 ;170-6:1999
• 41 cases metastatic to lung has been reported
• Inadequate and inappropriate treatment – recurrence
increased risk of metastasis
• Route aspiration of tumor particles/ hematogenous
spread

70. Rational approach to diagnosis and treatment of
ameloblastoma and OKC
Karen A O M Chapelle, Paul J W Stoclinge
British J Oral Maxfac Surg 42; 381-390 :2004

71. ameloblastoma

72. Ameloblastoma in children
R A Ord, R H Blanchaert Et Al
J Oral Maxfac Surg 60; 762-70 : 2002
 Differ
 Higher % unicystic and fast growing
 Mural invasion
 More aggressive surgery necessary

73. In discussion
Arie Shteyer suggest
1. Precise differential diagnosis
2. Conservative approach
 Decompression- Iodoform gauze
soaked in whiteheads varnish
3. Long term follow up
4. recurrence extensive surgery

74. Conclusion
• Careful examination
• Appropriate treatment
• Complete cure
• Reconstruction
• Follow up

75. THANK YOU