Radiolucent Odontogenic Lesions Flashcards
Cysts
- Pathologic sack or cavity w/ a central lumen lined by epithelium
- We make dx based on epithelial lining
- Slowly growing & asymptomatic (unless inflamed)
-
Persistent & progressive and can become large and destructive if not tx’d
- They’ll keep growing until you remove them
- Rad: Well-defined RL lesion, often corticated borders
- Do not infiltrate surrounding bone
Components of cysts
- Lumen
- Epithelial lining
- CT wall
Cyst Tx
Varies from enucleation to aggressive curettage
Where do the epithelial components of cysts come from inside the bone?
- Dental lamina
- Reduced enamel epithelium
-
Epithelial Rests (of Malassez) from HERS
- Remnants of odontogenesis
Odontogenic cysts of the jaw: Origin of epithelial rests
T/F: Cysts & benign tumors have similar appearance. Inflammatory & malignancy have similar appearance.
True, true.
- Cysts and benign tumors slowly push and displace anatomical structures
- Can’t move tooth anymore, creates smooth resorption that looks like it follows hydraulic apperarance in directional resorption
- Inflammatory lesions and malignancies are quick - grow around teeth quickly, area that is growing starts to get pushed out and expand = non-directional resorption
- PDL space gone
Radicular (Periapical) Cyst
- Assoc w/ necrotic debris & bacteria of non-vital pulp
- Origin of epithelium is Epithelial Rests of Malassez
- Pulp necrosis → Inflammation → Radicular granuloma → Keratinocyte GF → Proliferation of epithelial rests
- Most grow slowly
- Asymptomatic unless acutely inflamed
- Rad: PA, well circumscribed, RL; loss of lamina dura; cannot be differentiated from PA granuloma & abscess
-
Healing Radicular Cyst
- Original outline still seen
- Bone grows inward
-
“Rolled border” appearance
- After endo tx, bone starts filling back in from the outside to create rolled border
What is the most common developmental odontogenic cyst?
Dentigerous (Follicular) Cyst
Dentigerous (Follicular) Cyst
-
Most common developmental odontogenic cyst
- 2nd most common cyst
- Pathogenesis: Proliferation of reduced enamel epithelium
- Rad: Well-defined, unilocular RL around/associated w/crown of unerupted tooth, often corticated border
- Attached to the CEJ of unerupted tooth or odontoma
- Most common w/ M3s & MX K9s
- Generally asymptomatic and discovered on routine radiographic exam
Dentigerous (Follicular) Cyst: Clinical features
- Small cysts are asymptomatic
- Can grow to large sizes and cause bony expansion
- Pain and swelling if infected
Dentigerous (Follicular) Cyst: Radiographic features
- Well-defined and often corticated border
- May be extensive and destructive
-
Unilocular and multilocular
- Usually unilocular but anything can become multilocular as it gets bigger
- Can displace affected tooth
- Can result in root resorption of adjacent teeth
Dentigerous (Follicular) Cyst: Tx
- Enucleation and removal of affected tooth
- Marsupialization followed by excision for larger lesions (not commonly done)
- Little tendency to recur when completely removed
Eruption Cyst
-
ST analogue of dentigerous cyst
- Only in ST around alveolar crest
- Consists of cystic fluid and/or blood accumulated b/w erupting tooth and dental follicle
- Appears as soft translucent swelling in gingival mucosa overlying crown of erupting tooth; traumatized, can lead to eruption hematoma
- Purple if blood present
- Most common in children <10yo
- Dentigerous cyst that forms after it has broken through alveolar crest; cyst not in bone
Eruption Cyst Tx
- Not usually tx’d bc tooth will erupt
What is the second most common cyst?
Dentigerous (Follicular) Cyst
What is the 3rd most common cyst?
Keratocystic Odontogenic Tumor (Odontogenic Keratocyst)
Other name for Keratocystic Odontogenic Tumor
Odontogenic Keratocyst
Keratocystic Odontogenic Tumor
- AKA Odontogenic Keratocyst
- 3rd most common cyst
- Odontogenic cyst w/ specific microscopic features and clinical features
- Arises from dental lamina
- Relatively aggressive behavior & tx
- High recurrence rate
- Associated w/ nevoid basal cell carcinoma syndrome
Keratocystic Odontogenic Tumor: Clinical features
- Can occur in any odontogenic location
- Most common in MN body & ramus
- Tends to grow in anterior-posterior direction in MN
- Does not cause expansion in MN body typically
- More growth potential than other odontogenic cysts
- Higher rate of recurrence
- Large OKCs may be associated w/ pain, drainage, paresthesia
- Large OKCs do not tend to expand jaws
Keratogenic Odontogenic Tumor: Rad
- Assoc w/ unerupted tooth in 25-40% of cases
- Well-defined RL area
- Smooth corticated margin
-
Unilocular or multilocular
- Smaller lesions = unilocular
- Larger lesions = multilocular
- Usually displaces teeth
- Little to no expansion, despite large size; but CAN cause expansion, esp in ramus
- Frequently mimics other lesions
- Daughter cysts: Mini cysts around main cysts that get left behind when we enucleate the cyst
Why do OKCs occur often and have tumoral characteristics?
Daughter cysts: Mini cysts around main cysts that get left behind when we enucleate the cyst
OKC Tx
- Surgical excision w/ peripheral ostectomy, Carnoy solution
- Avg recurrence rate of 30%
- Most recur in 5yr, but may not until >10yr → long term clinical & radiographic f/u
- Occasionally, local resection and bone grafting are necessary
What would you include in differential dx along w/ OKC?
- Dentigerous (Follicular) Cyst
- Lateral Periodontal Cyst
- Nasopalatine Cyst
- Radicular Cyst
- Residual Cyst
- Primordial Cyst
- “Globulomaxillary” Cyst
- Idiopathic Bone Cavity
- Ameloblastoma & other benign odontogenic tumors
What is the only cyst that can be MIXED, while all others are ALWAYS RADIOLUCENT?
Calcifying odontogenic cyst
Lateral Periodontal Cyst
- Arise from dental lamina along lateral surface of the root
- From previous epithelium and normal around PMs
- Does not mess w/ PDL/lamina dura
- <2% of all jaw cysts
- Asymptomatic
- 75-80% in PM-K9-LI area
- MN > MX
- Assoc w/ vital or non-vital teeth
Lateral Periodontal Cyst: Rad
- Well-defined RL lesion
- Relatively small, usually <1cm
- Rad features are not dx’c
Lateral Periodontal Cyst: Tx
- Enucleation
Other names for Gorlin Syndrome
Nevoid Basal Cell Carcinoma Syndrome
Gorlin-Goltz Syndrome
Gorlin Syndrome
- AKA Nevoid BCC Syndrome, Gorlin-Goltz Syndrome
-
Autosomal Dominant
- PTCH1 gene mutation
What syndrome would a mutation in PTCH1 produce?
Gorlin Syndrome AKA Nevoid BCC Syndrome AKA Gorliln-Goltz Syndrome
Gorlin Syndrome: Most common clinical findings (>50%)
- Multiple BCCs
- Multiple odontogenic keratocysts
- Calcified falx cerebri
- Rib abnormalities
- Palmar plantar pits
- Ocular hypertelorism
- Enlarged head
- Spina bifida
Gorlin Syndrome: Px
- Most anomalies are minor and non-life threatening
- Px depends on behavior of skin cancers
- Keratocysts tx’d w/ enucleation
- Pts should avoid sunlight
- Jaw cysts tx’d by enucleation
- Deformities may result from operations
Gingival cyst of the adult
- ST counterpart of lateral periodontal cyst
- Predilection for MN K9/PM area
- Pts in 5th & 6th decades of life
- Found on facial gingiva or alveolar mucosa
- Technically a peripheral lateral periodontal cyst
- Painless, dome-like bluish or blue grey swelling
Gingival cyst of the adult: Tx
- Simple excision
- Excellent px
- No recurrence
Gingival cyst of the newborn:
Bohn’s nodules; Epstein’s pearls
- Reported in up to 50% of all newborns
- Small, superficial, keratin-filled cysts on alveolar mucosa
- Alveolar mucosa of infants
- More common in MX alveolus
Gingival cyst of the newborn: Tx
Bohn’s nodules; Epstein’s pearls
- Lesions spontaneously rupture
- Excellent px
- No tx indicated
- Rarely seen after 3mo
- No recurrence
Tumor
Mass of tissue; no lumen
Odontogenic tumors arise from one or more tissues present in tooth development, which are:
- Dental lamina
-
Enamel organ
- Ameloblasts, enamel
-
Dental papilla
- Odontoblasts, dentin, pulp
-
Dental follicle
- Cementoblasts, cementum, PDL, alveolar bone
WHO classification of odontogenic tumors tissue of origin
- Odontogenic epithelium w/ mature stroma w/o odontogenic ectomesenchyme
- Odontogenic epithelium w/ ectomesenchyme w/ or w/o HT
- Mesenchyme and/or ectomesenchyme w/ or w/o odontogenic
Odontogenic epithelium w/ mature stroma w/o odontogenic ectomesenchyme
- Ameloblastoma, central or peripheral
- Calcifying epithelial odontogenic tumor
- Adenomatoid odontogenic tumor
- Keratocystic odontogenic tumor
- Squamous odontogenic tumor
Odontogenic epithelium w/ ectomesenchyme w/ or w/o HT
- Ameloblastic fibroma
- Ameloblastic fibro-odontoma
- Odontoma: Compouund & complex
- Calcifying cystic odontogenic tumor (calcifying odontogenic cyst)
Mesenchyme and/or ectomesenchyme w/ or w/o odontogenic epithelium
- Odontogenic fibroma
- Odontogenic myxoma
- Cementoblastoma
Where would you find odontogenic tumors?
- Areas where teeth can form
- Most are central (w/in jaws)
- Others are peripheral (on the gingiva)
RL Odontogenic Tumors
- Ameloblastoma
- Ameloblastic fibroma
- Central odontogenic firbroma
- Odontoenic myxoma
Prevalence of ameloblastic subtypes
Multicystic > Unicystic > Peripheral
Ameloblastoma
RL Odontogenic Benign Tumor
- Most common in molar/ramus area of the MN
- 20-40yo, but occurs across all age ranges - don’t go based on age for this one
- No mineralized pdt ⇒ RL
- Unilocular or multilocular
-
Classically multilocular
- Key: Soap bubble w/ round septations and expansions
-
Classically multilocular
- Always RL
- Slowly growing; locally aggressive
- Locally infiltrates surrounding bone
- Painless swelling of the jaw
- Significant expansion of cortices and fracture on lingual
Ameloblastoma: Tx
RL Odontogenic Benign Tumor
- Marked tendency to recur if tx’d by curettage
- More extensive surgical removal is necessary: Removal of 1-2cm of surrounding bone past rad margins
- Tumor islands infiltrate bone, so we want to make sure that we remove them all
Unicystic Ameloblastoma
RL Odontogenic Benign Tumor
- A variant of ameloblastoma that resembles an odontogenic cyst
-
All tumor lines the cystic cavity and grows into the lumen; no invasion of CT wall
- Cystic cavity lined by ameloblastic epithelium
- Less aggressive than solid type
- Affects younger pts (10-20yo)
- Circumscribed RL around molar
- Mimics other lesions
Unicystic Ameloblastoma: Tx
RL Odontogenic Benign Tumor
- Dx is difficult - need rads, gross and microscopic confirmation
- Enucleation or curettage
- Initially enucleated
- 10% recurrence
- Careful enucleation w/ removal of unerupted tooth; usually resection no necessary
- Tooth can be left in some cases
Peripheral Ameloblastoma
RL Odontogenic Benign Tumor
- Painless lesion of gingiva or alveolar mucosa
- Same histopathology as intra-osseous form
Peripheral Ameloblastoma: Tx
RL Odontogenic Benign Tumor
- Innocuous behavior
- Tx’d w/ local excision
Ameloblastic Fibroma
RL Odontogenic Benign Tumor
- Consists of both odontogenic epithelium and ectomesenchyme
- Occurs in younger pts - 1st or 2nd decade
- Occur in pts YOUNGER THAN 20yo
- Slightly more common in males
- Small lesions are asymptomatic; large lesions cause swelling
- Typical location is posterior MN
Ameloblastic Fibroma: Rad
RL Odontogenic Benign Tumor
- Typical odontogenic RL lesion
- Does not infiltrate surrounding bone
- Well-defined, RL, well corticated, expansion of the MN, displaced teeth, directional resorption of roots
Ameloblastic Fibroma: Tx
RL Odontogenic Benign Tumor
- Enucleation or curettage
-
Good px
- Lower recurrence rates
- Initial tx more conservative
- More aggressive tx for recurrent lesions
- A rare malignant variant exists
If you see multilocular, think..
Ameloblastoma
OKC
Myxoma
Central Odontogenic Fibroma
RL Odontogenic Benign Tumor
- Consists of ectomesenchymal tissue similar to dental follicle
Central Odontogenic Fibroma: Rad
RL Odontogenic Benign Tumor
- Typical RL odontogenic cyst/tumor
- Does not infiltrate bone
Central Odontogenic Firboma: Tx
RL Odontogenic Benign Tumor
- Conservative surgical removal – enucleations, curettage
Odontogenic Myxoma
RL Odontogenic Benign Tumor
- Ectomesenchymal tumor
- Found in young adults (25-30yo)
- No gender predilection
- If small, no changes; larger lesions cause asymptomatic swelling
- Gelatinous appearance
- Infiltrates surrounding bone
- Dental papilla-like tissue
Odontogenic Myxoma: Rad
RL Odontogenic Benign Tumor
- Well-defined or poorly defined borders
- “Honeycomb” or “tennis racket” appearance
- Infiltrates surrounding bone
-
Key: Straight perpendicular septations
- Multilocular or septated appearance
Odontogenic Myxoma: Tx
RL Odontogenic Benign Tumor
- Need to remove some normal surrounding bone
- Req’s more aggressive tx
What are the RL Odontogenic Lesions?
- Inflammatory
- Radicular (Periapical) Cyst
- Residual Cyst
- Buccal Bifurcation Cyst
- Developmental
- Dentigerous (Follicular) Cyst
- Eruption Cyst
- Keratocystic Odontogenic Tumor
- AKA Odontogenic Keratocyst
- Lateral Periodontal Cyst
- Gorlin Syndrome
- AKA Nevoid BCC Syndrome, Gorlin-Goltz Syndrome
- Gingival Cyst of the Adult
- Gingival Cyst of the Newborn
- Tumors
- Ameloblastoma
- Unicystic Ameloblastoma
- Peripheral Ameloblastoma
- Ameloblastic Fibroma
- Cental Odontogenic Fibroma
- Odontogenic Myxoma
