Oral Cysts Flashcards
Describe the possible mechanisms of cyst formation.
- Entrapped remnants within connective tissue are stimulated to proliferate. Internal epithelial cells become necrotic as a result of being isolated from blood supply. This creates a hypertonic draw of fluids into the lumen producing a cyst.
- A normally present epithelial-lined space becomes enlarged.
- Epithelium could proliferate and migrate to line a cavity which developed in connective tissue as a result of some other pathological process, such as a abscess.
- Combinations of the above.
“A pathological, epithelium lined, cavity within connective tissue” is the definition of what?
A cyst
What is meant by the term “hypertonic” ?
More fluid outside in the connective than inside the cyst, so the gradient drives fluid into the cyst area
Name two examples of epithelial lined structures that commonly form cysts.
- An obstructed ducts. Duct continues to produce secretions that cannot be released and causes the duct to expand - presenting as a cyst.
- Cyst around the crown of a nun erupted tooth - reduced enamel epithelium, which is interposed between the dental follicle and the crown, gives rise to the lining cyst epithelium
What must occur for an abscess to form a cyst?
The cavity of the abscess must impinge on a epithelial structure
Which three factors determine the type of cyst that develops?
- Type of epithelium generated in the cyst
- Pathological process which resulted in cyst formation
- inflammatory stimulus
- poorly defined genetic or environmental factors active during
development
- The tissue structure in which the cyst develops
Which two types of epithelium are used to classify cysts, particularly in the jaw?
Odontogenic and non-odontogenic sources
What are sources of odontogenic epithelium?
- enamel organ
- fragments derived from the dental lamina: rests of Serres
- fragments derived from Hertwig’s root sheaths: cell rests of Malassez
- the remaining epithelium after the enamel organ has finished forming the crown: reduced enamel epithelium
What are the types of non-odontogenic cysts?
- NON-ODONTOGENIC DEVELOPMENTAL CYSTS: entrapped remnants, possibly derived from embryonic processes which give rise to the maxillofacial complex
- cysts caused by Implantation into bone of max sinus epithelium
- soft tissue cysts - formed by epithelium derived from hair follicles and other skin adnexal structures, implanted epidermis, salivary gland epithelium, thyroid gland or even GI epithelium
What is Gorlin-Goltz syndrome?
Jaw cyst - basal cell nevus
Bifid rib syndrome
Autosomal dominant trait
Features: multiple odontogenic keratocysts, mandibular prognathism, rib anomalies, brachymetacarpalism, vertebral anomalies, hypertelorism, basal cell carcinomas, Palmar and plantar pitting, rural calcification
What is a primordial cyst?
Refers to a cyst found in place of a missing tooth (not usually used as a diagnosis - preferred diagnosis is an odontogenic keratocyst)
What is suggested to be responsible for the high recurrence rate of odontogenic keratocysts?
Satellite cysts (found within fibrous tissue adjacent to the main cyst) left behind after surgery
What’s the difference between ortho and para keratinization?
Ortho - no nuclei present
Para - nuclei are present
What are the types of gingival cysts of the newborn?
Bohn’s - on posterior palate (border of hard and soft palate)
Epstein’s - occurs on midline of palate
Dental lamina cyst of the newborn - occur on ridge
Name the cyst:
- odontogenic, developmental, aggressive
- high recurrence rate
- derived from primitive enamel organ
- parakeratinzation(cannot use for diagnosis)
- bone expansion occurs as a late feature
ODONTOGENIC KERATOCYST
Name the cyst:
- odontogenic, developmental, aggressive
- orthokeratinized tissue
- does not have a high recurrence rate
- must be distinguished histopathologically
ORTHOKERATINIZED ODONTOGENIC CYST
Name the cyst:
- odontogenic, developmental, aggressive
- predilection for mand and max bicuspid and cuspid region
- small radiolucency found around lateral aspect of vital tooth
- thin squamous or cuboid epithelial layer with clear cells, often thickening into plaques
- doesn’t recur following conservative excision
LATERAL PERIODONTAL CYST
Name the cyst:
- odontogenic, developmental, aggressive
- occurs in the gingiva
- presents as a fluid filled swelling
- diagnosis: glandular odontogenic cyst (Sialo-odontogenic cyst)
GINGIVAL CYST OF THE ADULT
Name the cyst:
- odontogenic, developmental, aggressive
- appear as white nodules in infants
- are keratin filled balls lined by epithelium
- no treatment
- 3 types, named based on location
GINGIVAL CYST OF THE NEWBORN
Name the cyst:
- odontogenic, developmental, aggressive
- diagnosis comes from combined clinical and histopathologic information
- derived from reduced enamel epithelium after completion of crowns
- layer of stratified squamous epithelium which lines fibrous wall
- epithelial lining could show mucous metaplasia
- always associated with unerupted tooth
DENTIGEROUS (FOLLICULAR) CYST
Name the cyst:
- odontogenic, developmental, aggressive
- refers to a pericoronal cyst derived from reduced enamel epithelium which is clinically evident as a bluish soft tissue swlling over a non-exposed erupting tooth
ERUPTION CYST
Name the cyst:
- odontogenic, developmental, aggressive
- squamous epithelial lining of varying thickness, with or without epithelial nodules
- superficial cuboidal to columnar cells - occasionally ciliated
- lining contains duct like structures
- CLINICAL DIFFERENTIATION: median mandibular cyst
- HISTOPATHOLOGIC: intra-osseous low-grade mucoepidermoid carcinoma
- anterior
GLANDULAR ODONTOGENIC CYST (Sialo-odonotgenic cyst)
Name the cyst:
- odontogenic, inflammatory
- stimulus - non vital pulp
RADICULAR CYST
Name the cyst:
- odontogenic, inflammatory
- occurs in the site of an extracted tooth
- it could be regarded as a persistent radicular cyst, which did not resolve after tooth removal
RESIDUAL CYST
