Surgical Management of Cysts Flashcards
Define a cyst
A pathological epithelial lined cavity within tissue that can be filled with fluid or gas (not created by the formation of pus)
How are cysts classified?
Cysts are classified into:
Hard tissue cysts
Soft tissue cysts
Hard tissue cysts are further divided into:
Odontogenic cysts (arising from the tooth or tooth forming structures)
Non-odontogenic cysts (arising from the fusion of plates, processes or the premaxilla during embryological development of the face)
Non-epithelial lined cysts (present like cysts but are not truly cysts as they are not epithelial lined cavities)
Soft tissue cysts are further divided into:
Developmental cysts
Non-developmental cysts
When a patient presents with a suspected cyst, in general what special investigations should be requested?
X-rays, plain film or CBCT
Referral for biopsy of the area
Vitality testing of associated teeth
List some red flag symptoms in a patient who is suspected to have a cyst, that may indicate something more sinister (malignancy)
Altered sensation or neurological involvement, particularly of the ID nerve (numbness in the lip, chin or tongue)
Mobility of teeth with no evident underlying source e.g., periodontitis
Sudden onset of swelling
List all the methods of management for a cyst
Conservative
Decompression (marsupalisation)
Enucleation
Enucleation and curettage
Resection + margin
Describe the conservative approach to management of a cyst
Accept and adapt approach with a wait and watch policy
Used for patients with a small cyst, patients who are unfit for surgery or not keen on any surgical intervention
High risk of complications in the long-term
Need to ensure we have the correct diagnosis before committing to this approach to ensure the lesion is not suspicious or requires referral for further investigation
Describe decompression
Also known as marsupialisation (a process by which we reduce the size of a cyst prior to enucleation to allow easier removal)
Achieved by opening up a window into the cyst cavity and keeping this window open for a specific period, to allow the cyst to reduce over time. This will occur because the pressure within the cavity will reduce as a result of the opening, causing the cyst to become very small and easy to remove without damaging adjacent structures
Patients will have to keep this window into cavity very clean to prevent infection
List the advantages and disadvantages of the process of Marsupialisation
Advantages-
Simple management technique to treat cysts
Allows preservation of vital structures and teeth
Disadvantages-
Hygiene compliance required. Patient will have to keep this open window clean
Can be a lengthy procedure
Patient may require a 2nd procedure to complete the treatment
Describe enucleation
Refers to the removal of a cyst in its entirety
List the advantages and disadvantages of enucleation
Advantages-
Remove the entire specimen of the cyst
If done correctly, it is a curative management approach
Disadvantages-
Technically challenging, especially if the cyst is large and is located with great proximity to adjacent vital structures
Risk of damaging vital structures surrounding the cyst
Risk of pathological fractures (mandibular fracture etc.) with very large cysts during treatment
Describe the process of curettage
The cyst cavity is opened up and the epithelial lining is debrided (curetted out). The cavity is then given a clean and washed out.
The cyst is removed through a process of enucleation and then sent to histopathology.
Describe the process of resection and margin
Also known as a wide local excision
More commonly used for large or risky looking cysts
Involves excising the cystic lesion with a margin of clinically normal looking tissue to ensure the cyst is removed in its entirety
Give the greatest chances of curing the cyst
Describe the advantages and disadvantages of the resection and margin management technique
Advantages-
Useful for larger or riskier looking cysts
Offer the best chance of curing the cyst as we need to ensure we have a good margin of normal tissue during cyst removal. More likely to remove the entirety of the cyst using this technique therefore.
Disadvantages-
Can leave the patient with a significant deformity, as the cysts are usually very extensive
Can pose reconstructive challenges following cyst removal, leaving a wide area to reconstruct
Describe the mechanism of cyst growth
The presence of inflammation causes epithelium to proliferate and form an epithelial lined cavity.
The cells in the centre of this forming cyst will begin to break down. And there will be a change in the osmotic pressure (increases), causing water to be drawn inwards. This allows the cyst to expand and increase in size
A release of collagenase and prostaglandins by fibroblasts as well as osteoclast stimulating factors will result in bone resorption as the cyst expands
Describe the key features of cysts
Pathological epithelial lined cavity that may be filled with gas or fluid
Well defined, corticated mostly unilocular radiolucencies on a radiograph
Grow slowly, displacing rather than resorbing teeth
Usually symptomless unless they become infected (in which case they will cause pain/swelling)
Bone often becomes thin in the region of the cysts, this allows the cyst to extend into soft tissues (expansion) to cause a fluctuant soft swelling. Appear bluish when they’re close to the surface/extend into soft tissues
Sometimes, if these areas are touched, it may feel like cracked egg shells (this is when the risk of infection is high)
Describe the epidemiology of radicular cysts
Pathological epithelial lined cyst arising from the epithelial cell rests of Malassez within the PDL (in response to chronic inflammation at the apex)
Affect males>females
Affect maxilla>mandible (3:2)
50% of all cysts within the jaw are radicular cysts.
70% of all odontogenic cysts are radicular cysts.
Rare before 10 years of age, tend to affect individuals aged 20-60 years
Describe the epidemiology of dentigerous cysts
Pathological epithelial lined cavity arising from fluid collection between the enamel follicle and enamel surface
Affects males>females (2x)
Uncommon in children, usually affects those 20-50 years
Commonly affects 8s, 4s and U3s
Describe the management protocol for radicular cysts
If the cyst is small enough, we would treat the tooth with endodontics (RCT) and monitor.
But if they’re larger or a RCT is not possible, the cyst would need to be enucleated (removed in its entirety), to be sent to histopathology.
A primary closure should be undertaken following this to allow healing
Under the microscope, what do radicular cysts consist of?
The epithelium lining consists of stratified squamous epithelium of varying thickness in these cysts and often the capsule that encompasses them will have a collagenous fibrous connective tissue.
Within these cysts, histologically we would see chronic inflammatory cells, plasma cells which are a response to the antigenic material from a bacteria leaking out of the tooth’s apex
Describe the epidemiology of residual cysts
A radicular cyst which persists after extraction of offending tooth
Common in the elderly, especially those with edentulous jaws
Describe the epidemiology of lateral periodontal cysts
A pathological epithelial lined cavity that arises from tooth forming tissues (dental lamina, follicle or epithelial cell rests of Malassez within the PDL- origin not well understood)
Rare
Commonly affects 3s/4s (canines/premolars)
Describe the management protocol for lateral periodontal cysts
Enucleation
+/- XLA of adjacent teeth (only XLA’d if involved with the cyst in some way and causing the patient issues)
What is the management protocol for dentigerous cysts?
Marsupialisation (where cysts are particularly large)
Enucleation + XLA of associated unerupted tooth
Describe the features of odontogenic keratocysts
Pathological epithelial lined cavity arising from the dental lamina
Uncommon, 10% of all odontogenic cysts
High recurrence
Radiographically tend to present as multilocular, well defined, corticated radiolucencies with scalloped/rounded margins
Generally are low pressure cysts that extend in the path of least resistance
Often extend through the ramus and body of the mandible before causing expansion (therefore late clinical presentation)
Associated risk of ameloblastoma stimulation
May be associated with an unerupted tooth appearing similar to a dentigerous cyst
May displace adjacent teeth and ID canal
May damage adjacent teeth (root resorption)
Describe the epidemiology of odontogenic keratocysts
Peak incidence at 20-30 years (but can be 50-70 years)
Most commonly affect the angle of the mandible (50% of all cases)
Under a microscope, describe the features of an odontogenic keratocyst
Cyst lined by thin parakeratinised stratified squamous epithelium
Characteristic corrugated surface
Well defined basal cell layer (indicating non malignancy)
Connective tissue wall of cyst is not inflamed
What is the management protocol for odontogenic keratocysts?
Enucleation + curettage (gold standard)
Can be frozen via cryotherapy followed by enucleation.
Can undergo marsupialisation followed by enucleation
Can use Carnoy’s solution to fix the tissues, killing the cystic cells, followed by enucleation (but this can pose issues for nerves and are often neurotoxic)
Describe the epidemiology of ameloblastomas
Rare but most common neoplasm (benign)
Most commonly affects those aged 30-60 years
Rare in extremes of age
Affects mandible>maxilla
Affects posterior mandible>anterior mandible (ramus)
Describe the radiographic presentation of ameloblastomas
Rounded, moderately well defined, corticated radiolucency
Typically multilocular but can be unilocular, presenting similarly to cysts
Honeycomb pattern where multilocular
Difficult to distinguish from other pathologies using imaging alone
Describe the features of a calcifying epithelial odontogenic cyst
Also known as a Pindborg tumour
Variable behaviour (some argue they are not cysts but low grade tumours)
Sometimes mistaken as carcinomas on histological examination
Locally invasive but does not metastasise
Expansile lesion
Asymptomatic unless infected (in which case there will be swelling and pain)
Radiographically presents as radiolucent areas with poorly defined margins. Can have areas of calcification or odontomas within them.
Describe the epidemiology of calcifying odontogenic cysts
Rare
Commonly affect those that around 40 years of age
Commonly affect the posterior body of the mandible
What is the management protocol for calcifying odontogenic cysts?
Enucleation/excision of cyst with a small clear margin of normal tissue
Describe the features of a Staphne’s idiopathic bone cavity and its management protocol
Non-epithelial lined odontogenic cyst.
Developmental inclusion of submandibular salivary gland tissue in the lingual aspect of the mandible.
Radiographically presents as a well defined corticated round unilocular radiolucency, usually situated below the ID canal and not associated with the crown of an unerupted tooth or the apex of a non-vital tooth
Conservative treatment (non-surgical, leave and monitor)
Describe the features of an aneurysmal bone cyst
Non-epithelial lined odontogenic cyst
Benign, expands slowly, can be locally aggressive and capable of dysplastic change
Affects mandible>maxilla
Typically contains a blood filled space interspersed with giant cells and fibroblasts
High recurrence rate
Under a microscope, describe the features of an aneurysmal bone cyst
Non-epithelial lined cavity which contains a blood filled space interspersed with giant cells and fibroblasts
Describe the management protocol for aneurysmal bone cysts
Enucleation + curettage
Followed by sample to histopathology
Describe the features of a solitary bone cyst
Non-epithelial lined odontogenic cyst
Also known as traumatic bone cyst or unicameral cyst
Can be associated with childhood trauma
Often affect young adults
Can contain blood stained serous fluid or gas
Radiographically presents as a well defined, corticated, unilocular radiolucency with scalloped margins that extend up to the roots of associated teeth
Often associated with vital teeth
Describe the management protocol for solitary bone cysts
Enucleation + curettage
Followed by sample to histopathology
Describe the features of a naso-palatine duct cyst
Most common, non-odontogenic hard tissue cyst arising from the epithelial remnants of the nasopalatine duct (fusion of hard tissues during embryological development of the face)
Can clinically present as a swelling on the palatal aspect behind the upper central incisors
Radiographically presents as a round/pear shaped well defined corticated unilocular radiolucency that appears associated with the upper central incisors (located in the midline, on the palatal aspect)
High recurrence (due to poor treatment technique)
Describe the epidemiology of a nasopalatine duct cyst
Most common non-odontogenic hard tissue cyst
Commonly affects those aged 20-60 years
Affects males>females
Located in the maxilla behind upper central incisors
Under a microscope, describe the features of a nasopalatine duct cyst
Round/pear shaped cavity lined with stratified squamous and ciliated columnar epithelial cells
Describe the management protocol for nasopalatine duct cysts
Enucleation
