Cystic Lesions of the Jaw Flashcards
What is the definition of a cyst
Pathological cavity lined by epithelium
Fluid, semi-fluid or gaseous content, but not created by accumulation of pus
What is a pseudocyst?
Like a cyst but without epithelial lining
Elements of a cyst
Wall/capsule : fibrous CT w collagen fibers, BV, inflammatory cells
Epithelial lining
Cystic fluid in lumen
Common features of cysts
Most common chronic swelling of jaws
Jaws > bones due to presence of odontogenic epithelial remnants
Slow and expansile growth
May resorb and displace teeth
Asymptomatic unless large or infected
If extending to soft tissues forms a compressible and fluctuant swelling
Radiographical presentation of cysts
Well-defined round RL w smooth, corticated borders
Major factors of cyst expansion
1) Proliferation of epithelial lining and fibrous capsule
2) Resorption of surrounding bone
3) Hydrostatic pressure of cystic fluid as epithelium desquamates into the lumen, increasing protein content, causing osmosis into the lumen
Types of inflammatory odontogenic cysts
Radicular/periapical cysts
Paradental/buccal bifurcation cyst
Types of developmental odontogenic cysts
Bohn’s nodules, epstein pearls
Dental lamina cysts/gingival cyst of the newborn
Eruption cyst
Dentigerous cyst
Odontogenic keratocyst
Lateral periodontal cyst
Non-odontogenic cysts
Nasopalatine duct cysts
Types of pseudocysts
Simple bone cavity
Stafne bone defect
Aneurysmal bone cyst
What is a radicular cyst
Most common type of odontogenic cyst
PA granuloma that stimulated cell rests, forming a PA cyst
Derived from epithelial cell rests of Malassez in PDL fibers
Demographics of radicular cysts
Male > female
Usually 40-50yo
Types of radicular cysts
Apical
Lateral
Residual (inflammatory tissue not curetted after exo, removal of cyst incomplete)
Clinical presentation of radicular cysts
Max > mand
Slowly progressive swelling
Asymptomatic unless large or infected
Associated with a non-vital tooth, usually discolored permanent tooth
May cause adjacent teeth mobility
Radiographic presentation of radicular cysts
Well-defined ovoid unilocular RL
May have RO margin
Similar to granuloma but generally larger, >1cm
Loss of lamina dura
Can cause root resorption or bony expansion
Histopathologic findings of radicular cysts
Wall: collagenous/fibrous CT, chronic inflammatory infiltrate (lymphocytes, histiocytes, plasma cells), and cholesterol clefts
Epithelial lining: non-keratinized SSE from epithelial cell rests of Malassez
Cystic fluid: watery, opalescent liquid with cholesterol crystals
Diagnosis of radicular cyst
Vitality testing
Radiographic presentation
BUT clinical and radiographic findings are identical to periapical granuloma
Differentiating factor is histopathology
Management of radicular cysts
Non-surgical endodontic therapy
Exo
Recurrence uncommon, but if persistent then exo and curette or do apicoectomy and curettage
What is a buccal bifurcation cyst
Uncommon odontogenic cyst
Lining derives from epithelial cell rests of Malassez in PDL fibers
Usually in young px (5-13yo)
Often presents with buccal enamel extension into bifurcation, predisposing towards pocket formation
Clinical presentation of buccal bifurcation cysts
Swelling
Tender
Foul tasting discharge
Mand 1M > 2M
Occasionally bilateral
Identical presentation to periodontal abscess
Radiographic presentation of buccal bifurcation cysts
Well defined unilocular RL
Tipping of molar to make lingual cusps more prominent
Mand occ radiographs shows buccal location
Histopathologic findings of buccal bifurcation cysts
Nonspecific findings
Wall: chronic inflammatory cell infiltrate
Epithelial lining: SSE with areas of hyperplasia
Management of buccal bifurcation cysts
Enucleation without exo
Usually get complete healing within 1 year
What are palatal cysts (bohn’s nodules vs epstein pearls)
Found in 50-85% of neonates
Bohn’s nodules originate from epithelial remnants from development of minor salivary glands of palate
Epstein pearls originate from epithelial entrapment between the palatal shelves
Clinical presentation of palatal cysts
Usually multiple small (1-3mm) white or yellow-white papules
Bohn’s nodules found at junction of hard and soft palate or rarely at vestibular region
Epstein pearls found along midpalatal raphae
Histopathologic findings of of palatal cysts
Keratin-filled cysts lined by SSE
May have communication with mucosal surface
Management of palatal cysts
No treatment needed as the epithelium gradually degenerates OR cysts rupture into mucosal surface and eliminate keratin contents
What are dental lamina cysts
Derived from cell rests of Serres, remnants of dental lamina
Clinical presentation of dental lamina cysts
Multiple small (2-3mm) white papules with smooth surfaces
Along crest of alveolar ridge
Max > mand
Histopathologic findings of dental lamina cysts
Keratin-filled cysts with a thin, flattened epithelial lining with a parakeratotic luminal surface
Lumen contains keratinaceous debris
Management of dental lamina cysts
No treatment needed as they spontaneously involute and rupture
What are eruption cysts
Soft tissue variant of dentigerous cysts
Common in children <10yo
Develop from the separation of the dental follicle from the crown of the erupting tooth, within soft tissue overlying alveolar bone
Clinical presentation of eruption cysts
Single, soft, round pink/blue translucent swelling
Painless unless infected or traumatized
Traumatized cysts may have blue coloration (eruption hematoma)
Found on gingival mucosa overlying the crown of a erupting primary/permanent tooth, often max and mand incisors and permanent 1M
Histopathologic findings of eruption cysts
Surface oral epithelium
Underlying CT shows variable inflammatory cell infiltrate
Roof shows thin SSE
Management of eruption cysts
No treatment needed
Naturally marsupializes as tooth erupts
If symptomatic or causing delayed eruption, remove roof of cyst to release fluid and allow normal eruption
What is a dentigerous cyst
2nd most common odontogenic cyst after radicular cyst
Most common developmental odontogenic cyst
Develops from the separation of the dental follicle from the crown of the erupting tooth
Cyst lining develops from REE
Usually in 10-30yo, male > female
Pathogenesis of dentigerous cysts
Accumulation of fluid between the REE and tooth
Hypotheses as to WHY:
1) Follicle compressed by impacted tooth, increasing pressure and causing increased fluid transudation, accumulating between REE and tooth
2) PA inflammation from deciduous tooth causes inflammation of REE of permanent tooth, causing accumulation of inflammatory exudate between REE and crown
Clinical presentation of dentigerous cysts
Missing tooth or delayed eruption
Slow growing, but can be expansile
Small: often asymptomatic, incidental radiographic discovery
Large: painless, hard bony swelling, can cause facial asymmetry
Infected: pain and swelling
Associated with the crown of unerupted/impacted teeth, esp mand 3M, max 3M, max canines, mand 2PM
May be associated with supernumeraries or odontomas, uncommon in deciduous teeth
Radiographic presentation of dentigerous cysts
Unilocular RL (large cysts may have trabeculations and appear multilocular)
Well defined corticated RO borders (unless infected, where its ill-defined)
Pericoronal to impacted tooth, attached to CEJ
Can have displacement of adjacent bony borders and structures, teeth, or even root resorption
Histopathologic presentation of dentigerous cysts
Wall: collagenous/fibrous. If non-inflamed, minimal inflammatory infiltrate, loosely arranged. If inflamed, heavy inflammatory infiltrate, more collagenised, hyperplastic, rete ridges present
Epithelial lining: originates from REE, non-keratinized SSE to cuboidal, non inflamed, thin and flattened
Cystic fluid: yellow fluid
Management of dentigerous cysts
Surgical enucleation and exo of involved tooth
Recurrence is rare
If large, excisional biopsy of dentigerous cyst lining due to potential for odontogenic tumours
What is an odontogenic keratocyst
Arises from cell rests of Serres
Behavior different from other odontogenic cysts - infiltrative, aggressive growth, high recurrence rate, associated with nevoid basal cell carcinoma syndrome
Usually in 10-40yos
Male > female
Pathogenesis of odontogenic keratocysts
Active epithelial growth, high cell proliferation rate
Over-expression of proteolytic enzymes causing bone resorption
Hydrostatic pressure plays a minimal role!
Types of odontogenic keratocysts
Parakeratinized (aggressive) = OKC
Orthokeratinized (non-aggressive) = ortho-keratinized odontogenic cyst
Clinical presentation of odontogenic keratocysts
A-P growth, extensive bone destruction with expansion within medullary cavity of bone
Small: asymptomatic, found on routine radiographs
Large/infected: pain, swelling, drainage
Mand > max
Posterior > anterior
May be associated with unerupted teeth
Epicenter superior to IDN
Radiographic presentation of odontogenic keratocysts
Often unilocular but can be multilocular esp in large lesions in post mand
Well-defined corticated RL with smooth scalloped borders
Tunnels in bone rather than expanding
Less likely to cause bony expansion, tooth displacement and root resorption than dentigerous cysts and ameloblastomas
Histopathologic findings of odontogenic keratocysts
Wall: thin, fragile, hard to enucleate intact. Loose collagenous/myxoid presentation, no inflammation, can have satellite/daughter cysts, potential for recurrence
Epithelial lining: parakeratinized stratified epithelium. Weakly attached to underlying CT, remnants remain after cyst enucleation so potential for recurrence
Fingerlike extensions into cancellous bone so hard to remove lining
Fluid: thick, yellow, creamy/cheesy keratin debris
Unique! So diagnosed histologically
Management of odontogenic keratocysts
Surgical enucleation and curettage
High recurrence rate (25-60%)
Long term clinical and radiographic follow up
What is a lateral periodontal cyst
Uncommon odontogenic cyst occurring along a lateral root surface
Usually in 50-70yo
Male > female
Arises from cell rests of Serres
Soft tissue variant is gingival cyst of the adult
Clinical presentation of lateral periodontal cysts
Asymptomatic, found on routine radiographs
Teeth still vital
Mand > max
PM-canine-LI region!
Histopathological findings of lateral periodontal cysts
Wall: thin, non-inflamed, fibrous
Epithelial lining: non-keratinized and thin with focal nodular thickenings
Diagnosed histologically!
Radiographic features of lateral periodontal cysts
Well-defined ovoid unilocular RL lateral to roots of VITAL teeth
Usually small, <1cm
Can cause root divergence
Polycystic variant is multilocular
Management of lateral periodontal cysts
Conservative enucleation, recurrence unusual
What is a nasopalatine duct cyst
Most common non-odontogenic cyst
Intraosseous developmental cyst caused by spontaneous degeneration of remnants of the nasopalatine duct
Arises from remnants of the nasopalatine canal!
Usually 40-60yo, male > female
Clinical presentation of nasopalatine duct cysts
Slow growing dome-shaped fluctuant swelling
May be bluish if near surface
Asymptomatic
May penetrate labial cortex, showing swelling below maxillary labial frenum
May drain into oral cavity - salty taste
Midline of anterior palate, overlying incisive canal, posterior to CIs and palatine papilla
Radiographic presentation of nasopalatine duct cysts
Well-defined round/heart-shaped unilocular RL
In midline between roots of max CIs
May push root apices of CIs apart
May expand labial/palatal cortex of maxilla
May displace CIs
Root resorption is rare
Histopathologic findings of nasopalatine duct cysts
Wall: neurovascular bundles, may have small mucous glands and small islands of hyaline cartilage. Mild to heavy chronic inflammatory infiltrate
Epithelial lining: varies from SSE to pseudostratified columnar epithelium, may have cilia/goblet cells
Management of nasopalatine duct cysts
Surgical enucleation, avoid nasopalatine nerve
Cyst large and risk of devitalization of CIs or creating a oral-antral fistula = marsupialization
Low recurrence rate
What is a simple bone cavity
Empty bone cavity with no epithelial lining (pseudocyst)
Usually in 20yo
Trauma causes intraosseous hematoma, breakdown of bloodclot creates an empty bone cavity
Clinical presentation of a simple bone cavity
Asymptomatic
May have pain and paresthesia
Mand > max
Posterior > anterior
Radiographic presentation of simple bone cyst
Well defined irregular unilocular RL with scalloped/rounded borders
1-10cm in size
Tooth displacement and root resorption are rare
May be ill-defined and multilocular!
Histopathologic findings of simple bone cyst
Lacks epithelial lining
Wall: thin layer of vascular fibrous CT, may have fibrin, erythrocytes, giant cells or lace-like dystrophic calcifications
Management of simple bone cyst
Surgical exploration and curettage to induce bleeding and healing by secondary intention
Periodic radiographic review until complete resolution
What is a stafne bone defect
Depression on lingual surface of mand lined by lingual cortex
No epithelial lining (pseudocyst)
Usually in middle aged and older adults
Male > female
Clinical presentation of stafne bone defects
Asymptomatic
Remains stable in size, but may increase slightly over time
Mand post (below IDN canal) around submand area
Mand ant (apex of anterior teeth) around sublingual area
Radiographic presentation of stafne bone defects
Well circumscribed ovoid RL with sclerotic border, usually unilateral
Management of stafne bone defects
No treatment needed
What is an aneurysmal bone cyst
Intraosseous accumulation of blood-filled spaces
No epithelial lining (pseudocyst)
Usually in <30yo
Female > male
Clinical presentation of aneurysmal bone cysts
Fairly rapid bony swelling, usually buccal or labial
May have pain or be tender on palpation
Mand > max
Posterior > anterior
Radiographic presentation of aneurysmal bone cysts
Well-defined unilocular circular RL
May have tooth displacement or root resorption
Larger lesions may be multilocular with wispy septae and dramatic expansion and thinning of bone cortices
Histopathologic findings of aneurysmal bone cysts
RBC filled space of varying sizes
Lacks epithelial lining
Surrounded by fibrous CT and reactive bone
Management of aneurysmal bone cysts
Surgical curettage (20-50% recurrence)
Partial resection (10% recurrence)
Clinical and radiographic follow-up for recurrence
