Docstoc

Odontogenic Cysts Tumors 2 of 3

Document Sample
Odontogenic Cysts  Tumors 2 of 3 Powered By Docstoc
					Keratocystic Odontogenic Tumor W.H.O. Definition
• a benign uni-or multicystic, intraosseous tumor of odontogenic origin • lining is parakeratinized stratified squamous epithelium • potential aggressive, infiltrative behavior • solitary or multiple (multiple usually related to Gorlin syndrome)

Synonyms
• Odontogenic Keratocyst (OKC) • Primordial Cyst

Histogenesis
• Dental lamina or its remnants • Extensions of basal cells from the overlying oral epithelium

Cause
Recent studies have demonstrated the role of the PTCH gene

Genetics
PTCH gene has been mapped to chromosome 9q22.3 - site of Gorlin Syndrome For Gorlin Syndrome •Two-hit mechanism •Leads to over expression of bcl-1 and TP53 •Evidence that PTCH gene is a significant factor in the development of KOT not associated with the Gorlin Syndrome

Genetics

(2)

PTCH - Sonic Hedgehog Pathway •Sonic Hedgehog, Patched, and Smoothened are genes conserved from flies to humans •Loss of function mutations in Patched and activating mutations in Smoothened are implicated •Abnormal activation of the SH pathway leads to development of disease through transformation of adult stem cells to tumor stem cells

1

Nevoid Basal Cell Carcinoma (Gorlin) Syndrome
• Multiple basal cell carcinomas • Multiple jaw cysts (odontogenic keratocysts) • Numerous bone abnormalities including bifid ribs, intracranial calcification, vertebral anomalies • Mild ocular hypertelorism • Epidermal cysts of the skin • Etc.

Gorlin (Nevoid Basal Cell Carcinoma) Syndrome

Basal cell carcinomas in non-sun exposed areas

Multiple OKCs

2

2 Week female brought to pediatric dentistry clinic parents were very upset Gingival cysts of the newborn No treatment needed - they’ll regress in a short time

Keratinizing odontogenic cyst. No relation to Keratocystic Odontogenic Tumor - No problems beyond odontogenic cyst

Gingival Cyst of the Adult

3

Gingival cyst

Lining derived from remnants of the dental lamina

Malignant lymphoma

Lateral Periodontal Cyst

Derived from remnants of the dental lamina

“Globulomaxillary” Cyst Cyst of the globulomaxillary area

4

“Ghost” cells calcify

Calcifying Odontogenic (Gorlin) Cyst

WHO 2005 •Calcifying Cystic Odontogenic Tumor •Dentinogenic Ghost Cell Tumor •Ghost Cell Odontogenic Carcinoma

Glandular Odontogenic Cyst

5

Squamous cell carcinoma arising in the epithelial lining of a cyst

A rare, but definite possibility in any cyst

Don’t ever throw tissue away
You’ll have trouble explaining to your kids why you can’t afford to send them to college

6

Origin of Odontogenic Cysts & Tumors
Odontogenic Apparatus
• • • • • • Remnants of dental lamina Reduced enamel epithelium Odontogenic rests Dental papilla Basal cell layer of oral mucosa Lining of odontogenic cysts

Odontogenic Tumors Can Be Found ANYWHERE!

Epithelial Tumors
•Ameloblastoma •Adenomatoid odontogenic tumor •Calcifying epithelial odontogenic tumor (Pindborg tumor) •Squamous odontogenic tumor •Clear cell odontogenic carcinoma

Ectomesenchymal Tumors
•Odontogenic myxoma •Granular cell odontogenic tumor •Central odontogenic fibroma •Cementoblastoma

• Odontoma – Compound – Complex • Ameloblastic fibroma • Ameloblastic fibro-odontoma • Ameloblastic fibrosarcoma • Odontoameloblastoma

Mixed Odontogenic Tumors

7

Epithelial Tumors
•Ameloblastoma •Adenomatoid odontogenic tumor •Calcifying epithelial odontogenic tumor •Squamous odontogenic tumor •Clear cell odontogenic carcinoma

Epithelial Tumors
•Ameloblastoma •Adenomatoid odontogenic tumor •Calcifying epithelial odontogenic tumor •Squamous odontogenic tumor •Clear cell odontogenic carcinoma

Multilocular, expansile radiolucency

Peripheral, palisaded cells with nuclei polarized away from the basement membrane

8

Palisade

9


				
DOCUMENT INFO
Shared By:
Categories:
Stats:
views:308
posted:4/24/2008
language:English
pages:9