Odontogenic & Nonodontogenic Cysts

Cyst Characteristics

• A keratocyst is essentially the same histologically as squamous epithelial lined cysts.
• A periapical cyst typically appears as a well-circumscribed periapical radiolucency with widening of the PDL space and/or loss of lamina dura.
• A dentigerous cyst is a central (within bone) lesion.
• A dentigerous cyst can grow to large dimensions if left untreated and usually appears as a well-circumscribed periapical radiolucency.

Epithelial Characteristics

• Squamous epithelium serves as the cellular covering of internal and external body surfaces, including the lining of vessels and small cavities.

Cyst Appearance

• A hemorrhagic cyst may result in bleeding into the cystic space, causing it to appear purple or blue in color.
• A gingival cyst of the adult typically appears in the most common location of the anterior mandible.
• The gingival cyst of the adult is the counterpart of the lateral periodontal cyst.

Cyst Behavior

• A dentigerous cyst is unlikely to recur and is often removed by simple surgical excision.
• A gingival cyst of the adult is characterized by dome-like swellings up to 5 mm in diameter, often with a bluish or grayish hue.

Radiographic Findings

• A periapical cyst is not associated with a radiolucent lesion surrounded by a radiopaque border.
• A calcifying odontogenic cyst (COC) exhibits features of glandular differentiation within the epithelium.
• A paradental cyst typically presents in the age group of 10-20 years.
• An odontogenic keratocyst (OKC) can cross the midline and presents as a uni- or multilocular radiolucency with a well-defined corticated border.

Treatment

• The recommended treatment for an eruption cyst is surgical excision.
• Vismodegib is a medication that inhibits the sonic hedgehog pathway by binding smoothened (SMO).

Calcifying Odontogenic Cyst (COC)

• The typical radiographic appearance of COC is a uni- or multilocular radiolucency with a well-defined corticated border.
• The mean age of presentation for dentinogenic ghost cell tumor is 34 years.
• A characteristic histological feature of COC is the presence of ghost cells.

Odontogenic Keratocyst (OKC)

• The term "keratocyst" is used to describe a cyst in a particular anatomic location, but is not a diagnosis.
• A characteristic histologic finding used to diagnose OKC is the presence of a parakeratinized stratified squamous epithelium.
• A reason for the increased risk of recurrence of OKC is the presence of satellite cysts.
• Marsupialization is not typically associated with OKC treatment.

Nevoid Basal Cell Carcinoma Syndrome

• A characteristic syndrome finding of Nevoid Basal Cell Carcinoma Syndrome is the presence of multiple odontogenic keratocysts.
• A characteristic feature of skin tumors present in Nevoid Basal Cell Carcinoma Syndrome is the presence of basal cell carcinomas.

Other Cysts

• A buccal bifurcation cyst is most commonly associated with pain or drainage.
• A nasopalatine cyst has a radiographic appearance resembling a 'heart' shape.
• A nasoalveolar cyst is thought to represent odontogenic cysts or tumors.
• A globulomaxillary cyst is characterized by a gross appearance resembling a 'blood soaked sponge'.
• A nasolabial cyst is not within the bone but is in the sinus.
• A dermoid cyst is considered a form of teratoma and can be found anywhere in the oral cavity.
• A dermoid cyst has a cavity lined by stratified squamous epithelium with a granular layer and abundant keratin on the epithelial surface and in the lumen.
• An epidermoid cyst feels doughy or rubbery upon palpation and has a histological appearance similar to skin with adnexal structures in the cyst wall.
• A thyroglossal duct cyst is the most common developmental cyst of the neck and develops from epithelial remnants of the tract which forms when the thyroid anlage descends into the neck.
• A Stafne cyst is an asymptomatic focal concavity of the cortical bone on the lingual aspect of the mandible, believed to be developmental in origin.