Odontogenic Cysts and Tumors Flashcards
the most common developmental odontogenic cyst; originates secondary to the separation of the follicle from the crown of an unerupted tooth; enlargement occurs secondary to increased osmotic pressure within the lumen of the cyst
dentigerous cyst
M>F; 2nd and 3rd decades; mandibular 3rd molars most common, followed by maxillary canines; typically asymptomatic or a painless expansion; unilocular radiolucency; affected tooth may by displaced; may see root resorption of adjacent teeth
dentigerous cyst
soft tissue counterpart to the dentigerous cyst; occurs within the soft tissue overlying the alveolar bone
eruption cyst
under 10 years; typically involves mandibular molars; soft, translucent swelling of the gingival mucosa overlying an unerupted tooth
eruption cyst
traditionally, defined as a cyst that develops in place of a missing tooth; most are histologically diagnosed as odontogenic keratocyst
primordial cyst
distinct odontogenic cyst with specific histologic features and clinical behavior; arises from cell rests of the dental lamina; also associated with nevoid basal cell carcinoma syndrome
odontogenic keratocyst
M>F; 10-40 years; mandible>Maxilla; rarely cause expansion; unilocular to multilocular radiolucency
odontogenic keratocyst
not necessarily a clinical type of cyst, but an odontogenic cyst that microscopically has an orthokeratinized lining; markedly different clinical behavior from the odontogenic keratocyst
orthokeratinized odontogenic cyst
nonspecific; M>F; young adults; most involve the mandibular third molars; stratified squamous epithelium that exhibits a prominent layer of orthokeratin
orthokeratinized odontogenic cyst
autosomal dominant syndrome secondary to mutations in the patched (PTCH) tumor suppressor gene; high penetrance and variable expressivity; features multiple basal cell carcinomas of skin, odontogenic keratocysts, rib and vertebral anomalies, and intracranial calcifications
nevoid basal cell carcinoma syndrome (gorlin syndrome)
frontal and temporoparietal bossing; ocular hypertelorism; multiple and early basal cell carcinomas; palmar/plantar pitting; bifid ribs and other skeletal anomalies; calcified falx cerebri; multiple odontogenic keratocysts
nevoid basal cell carcinoma syndrome
superficial, keratin-filled cysts on the alveolar mucosa; arise from remnants of the dental lamina; similar in appearance (although not location) to Epstein’s pearls and Bohn’s nodules
gingival cyst of the newborn
maxilla>mandible; multiple small papules on the alveolar processes of neonates
gingival cyst of the newborn
soft tissue counterpart of the lateral periodontal cyst; derived from rests of the dental lamina; 5th-6th decade; mandibular canine-premolar area; blue to blue-gray dome-shaped swelling
gingival cyst of the adult
Developmental (not inflammtory) cysts that typically occurs along the lateral root surface; probably arises from rests of the dental lamina
lateral periodontal cyst
M>F; over age 30; mandibular canine-premolar area; well circumscribed radiolucency lateral to the root of a vital tooth (multilocular=botyroid)
lateral periodontal cyst
uncommon cyst, sometimes associated with other odontogenic tumors; if no cystic component is present, epithelial odontogenic ghost cell tumor or deninogenic ghost cell tumor is more appropriate
calcifying odontogenic cyst
avg. age 33; maxilla=mandible, often involving the maxillary incisor-canine region; may be peripheral; unilocular radiolucency, often with radiopaque structures within the lesion; most lesions are 2-4 cm; may see root resorption or divergence
calcifying odontogenic cyst
rare odontogenic cyst that shows features of glandular differentiation; also referred to as sialo-odontogenic cyst; the pathogenesis of this lesion is unknown; adults, mandible; strong predilection for the anterior portions of the jaws; may cross the midline
glandular odontogenic cyst
larger lesions capable of bony expansion; well-defined unilocular or multilocular radiolucency with a sclerotic rim; “hobnail” appearance to the luminal epithelial cells
glandular odontogenic cyst
may arise de novo or from malignant transformation of a pre-existing cyst or neoplasm; must rule out the possibility of metastatic carcinoma
carcinoma arising in odontogenic cysts
M>F, older patients; pain, swelling, parasthesia; irregular, ragged radiolucency
carcinoma arising in odontogenic cysts
the most common of the odontogenic epithelial neoplasms; arises from odontogenic epithelium
ameloblastoma
M=F, avg, age 34; asymptomatic swelling and expansion; posterior mandible; multilocular radiolucency, often associated with an unerupted tooth; resorption of roots is common
conventional ameloblastoma
ameloblastoma _ variant: predilection for anterior regions of jaws; radiographic resemblance to fribro-osseous lesions
desmoplastic
_ pattern of ameloblastoma: islands of epithelium resembling the enamel organ with peripheral palisading and reverse polarity; central area resembling stellate reticulum
follicular
_ pattern of ameloblastoma: anastomosing cords or sheets of cells; peripheral palisading and reverse polarity
plexiform
_ pattern of ameloblastoma: squamous metaplasia within the tumor islands; keratin formation with occasional keratin pearls
acanthomatous
_ pattern of ameloblastoma: cells within the islands are characterized by a granular cytoplasm
granular cell
_ pattern of ameloblastoma: small islands and cords of odontogenic epithelium; dense fibrous stroma
desmoplastic
_ pattern of ameloblastoma: nests of basaloid cells; peripheral islands more cuboidal than columnar
basal cell
controversy regarding its definition; some feel that the lesion must be unilocular; others believe that multilocular is acceptable if the internal aspect is cystic; 10-15% of intraosseous ameloblastomas; previously thought less aggressive lesion with significantly lower recurrence rate, but this has recently been disputed
unicystic ameloblastoma
younger patients; mandible, usually posterior; asymptomatic or painless swelling; circumscribed radiolucency
unicystic ameloblastoma
uncommon variant; probably arises from submucosal rests of odontogenic epithelium or from the basal layer of the surface epithelium
peripheral ameloblastoma
middle aged patients; painless gingival swelling; posterior mandible; may superficially erode bone, but overall no radiographic evidence of intraosseous lesion
peripheral ameloblastoma
cytologically malignant ameloblastoma
ameloblastic carcinoma
cytologically benign lesion showing metastasis
malignant ameloblastoma
avg. age 30; metastatic site primarily the lungs, often after 10 years
malignant ameloblastoma
sixth decade; ill-defined, destructive lucency
ameloblastic carcinoma
uncommon tumor of uncertain histogenesis; thought to arise from stratum intermedium of enamel organ; other theories of histogenesis include rests of the dental lamina; posterior mandible; adults; painless, slow-growing swelling
calcifying epithelial odontogenic tumor
often associated with impacted tooth; unilocular to multilocular; radiolucent, with or without “driven-snow” radiopacities; amyloid (congo red positive); Liesegang rings
calcifying epithelial odontogenic tumor
benign odontogenic tumor that arises either from rests of the dental lamina of the rests of Malassez; the tumor tends to originate from within the periodontal ligament; probably diagnosed previously as a variant of ameloblastoma or even squamous cell carcinoma
squamous odontogenic tumor
M=F, avg, age 38; painless or slightly painful swelling; mobility of associated teeth; triangular radiolucency; SOT-like proliferations
squamous odontogenic tumor
originally included in the variants of ameloblastoma; thought derived from the enamel organ epithelium or possible remnants of the dental lamina; may produce dentinoid material, rarely enamel matrix
adenomatoid odontogenic tumor
F>M; Most occur during the second decade; anterior maxilla; large lesions cause a painless expansion; circumscribed radiolucency involving the crown of an unerupted tooth; extends beyond the CEJ; may contain “snowflake” calcifications
adenomatoid odontogenic tumor
thick fibrous capsule; aggregates of spindle shaped cells frequently in a whorled arrangement; variable numbers of duct-like structures; may contain small foci of calcification
adenomatoid odontogenic tumor
mixed odontogenic tumor with both neoplastic epithelial and mesenchymal tissues; many of these may actually represent early developing odontomas
ameloblastic fibroma
M>F, first 2 decades; posterior mandible; many associated with an unerupted tooth; unilocular or multilocular radiolucency
ameloblastic fibroma
mesenchymal tissue resembling the dental papilla (pulp); odontogenic epithelium in islands or cords; epithelial portion resembles developing enamel organ
ameloblastic fibroma
most common odontogenic tumor; two types: compound and complex
odontoma
first 2 decades; large painless expansion; may see ghost cells
odontoma
_ odontoma: posterior maxilla or mandible; calcified mass with the density of tooth structure
complex
_ odontoma: anterior maxilla; multiple tooth-like structures with radiolucent rim
compound
uncommon lesion with two described histologic subytpes, although this has recently been questioned; simple type and WHO type
odontogenic fibroma
F>M, avg. age 40; maxilla, anterior to the first molar; expansion, loosening of teeth; unilocular to multilocular radiolucency; root resorption or divergence
odontogenic fibroma
_ type of odontogenic fibroma: background of fine collagen fibrils with stellate fibroblasts; may see small foci of odontogenic epithelium
simple
_ type of odontogenic fibroma: more cellular fibrous connective tissue; strands and nests of odontogenic epithelium
WHO
soft tissue counterpart to the odontogenic fibroma; most similar to the WHO type
peripheral odontogenic fibroma
slow growing gingival mass; may cause tooth displacement; radiograph may show areas of calcification within the soft tissue mass
peripheral odontogenic fibroma
considered to be of odontogenic origin, resembling the odontogenic ectomesenchyme; histologically resembles the mesenchymal portion of a developing tooth
myxoma
M=F, age 25-30; mandible>maxilla; asymptomatic expansion; “soap bubble” radiolucency
myxoma
