CH15- Mixed Odontogenic Tumors Flashcards
What are the 6 mixed (epithelial and ectomesenchymal) odontigenic tumors?
1.ameloblastic fibroma 2.ameloblastic fibro-odontoma 3.Ameloblastic fibrosarcoma 4.Odontoameloblastoma 5. Compoound odontoma 6. Complex odontoma
What tumor was commonly diagnosed as an early stage odontoma before it go its own name?
Ameloblastic fibroma
Ameloblastic fibroma: age? sex? location?
Young 1st-2nd decade…slightly male, 70% in posterior mandible
What clinical characteristic is associated with an ameloblastic fibroma 75% of the time?
an unerupted tooth
Microscopically, the tumor is composed of a cell-rich mesenchymal tissue resembling the primitive dental papilla admixed with proliferating odontogenic epithelium.
Ameloblastic fibroma
What are the two patterns of the epithelial component of an ameloblastic fibroma?
1.long narrow cords 2 cells thick of cuboidal or columnar cells OR 2. small descrete islands that look like the follicular stage of the developing enamel organ
What is an important distinguishing feature of the epithelial islands in an ameloblastic fibroma vs an ameloblastoma?
AF = NO microcyst formation
What is the REAL recurrence rate of AFs?
0-18%
Recurrent AFs are at risk for what 35% of the time?
Ameloblastic Fibrosarcoma
________ is a tumor with the general features of an ameloblastic fibroma but that also contains ENAMEL and DENTIN
Ameloblastic fibro-odontoma
AF-O: age? location? sex?
10 yrs…posterior mandible…male
AF-O: the soft tissue component is histologically identical to what?
Ameloblastic Fibroma
What is the varient of ameloblastic fibro-odontoma in which there is NO enamel formation and ONLY dentin formation?
ameloblastic fibro-dentinoma
What is the recurrence rate for AF-O?
7%
Ameloblastic Fibrosarcoma: in most cases, which histological component looks malignant while the other remains bland?
the mesenchymal portion looks malignant and the epithelial portion looks bland
Most ameloblastic fibrosarcomas are considered to be de novo, but what % arise from another entity? What are the two entities?
33% from ameloblastic fibroma or ameloblastic fibro-odontoma
Ameloblastic fibrosarcoma: age? sex? location?
1.5 times more often for males, 27.5 years, 80% of cases in the mandible
In some cases of ameloblastic fibrosarcoma with multiple recurrences, the epithelial component becomes progressively less conspicuous so that the tumor eventually shows only WHAT?
a poorly differentiated fibrosarcoma
Woah.. in a few instances of ameloblastic fibrosarcoma, dysplastic dentin or small amounts of enamel may be formed…what are two (unnessisary) subclassification names?
ameloblastic dentinosarcoma..ameloblastic fibroodontosarcoma
What is an ameloblastic fibrosarcoma that now has transformation of BOTH epithelial and mesenchymal elements?
ameloblastic carcinosarcoma
Odontoameloblastoma: age? location?
younger…either jaw
What does an odontoameloblastoma resemble radiographically??
complex odontoma
Name that tumor: The proliferating epithelial portion of the tumor = ameloblastoma, most often of the
plexiform or follicular pattern…intermingled with immature or more mature dental tissue = compound odontoma, or complex odontoma
Odontoameloblastoma (no histology picture in Neville lol)
What is the clinical significance between an odontoameloblastoma and an ameloblastic fibro-odontoma?
Odontoameloblastoma: same biologic potential as ameloblastoma (15-90% recurrence rate) VS ameloblastic fibro-odontoma: 7% recurrence
The most common odontogenic tumor, prevelance exceeding all others combined…
odontoma
_________ odontoma is composed of
multiple, small toothlike structures.
compound
________ odontoma consists of a conglomerate mass of enamel and dentin, which bears no anatomic resemblance to a tooth.
complex
________ odontomas are more frequently diagnosed than ________ , and it is possible that they are not even submitted for microscopic examination
compound more than complex
Odontoma: age? location? more specific location for compound odontoma?
14 years….somewhat more frequently in the maxilla…compound is more in the ANTERIOR MAXILLA
A complex odontoma can be radiographically confused with ________
an osteoma (just dense RO lesion)
Complex odontomas histologically consist largely of ___________
mature tubular dentin
Small islands of eosinophilic-staining epithelial
_______ cells are present in about 20% of complex odontomas.
ghost
Complex odontoma: A thin layer of ________ is often present about the periphery of the mass.
cementum
Occasionally, a _________ may arise from the epithelial lining of the fibrous capsule of a complex odontoma.
dentigerous cyst
