Odontogenic keratocyst / histopathology, clinical and radiographic features

 Odontogenic keratocyst ( OKC )

• A cyst derived from the remnants of dental lamina with a biological behaviour similar to a benign neoplasm with a distinctive lining of 6 to 10 cells in thickness and that exhibit a basal cell layer of palisaded cells and a surface of corrugated  parakeratin.
• Odontogenic keratocysts (OKC) are ususally present intraosseous but extraosseous OKC sometimes also present termed as peripheral OKC.

Clinical features

• Occurs in wide age span 1st decade to 8th decade of life but most commonly present in 2nd and 3rd decade of life.
• Most commonly present in posterior body of the ramus. 
• Sometimes it resemble dentigerous cyst but is not limited to CEJ.
•  It has remarkable growth potential resulting in massive bone destruction.
•  Reoccurrence rate is 25 to 60% similar to ameloblastoma.
  

Radiographic features

•  Appear well defined solitary lesion with smooth or scalloped margins or as multilocular radiolucency exhibiting thin corticated margin. 
  

Histopathological features

•  Thin uniform Lining of perakeratinized squamous epithelium usually 6 to 10 cell layer thick.
•  A palisaded layer of columnar or cuboidal basal cells.
•  A corrugated rippled layer of parakeratin on its luminal surface.
•  A lack of rete pegs.
•  Cystic lumen contain desquamated parakeratin. 
•  Also has satellite cyst.
•  Parakeratin has corrugated appearence. 

Why OKC has high recurrence?

• It has satellite cyst.
•  There is focal seperation of epithelial lining from connective tissue.
•  Lack of rete pegs.
•  Parakeratinzed OKC has higher recurrence rate than orthokeratinized vairiant which is 5%.

Nevoid basal cell carcinoma

Features of nevoid basal cell carcinoma:

• Multiple odontogenic keratocysts of jaws
• Multiple basal cell carcinoma of skin
• Bifid ribs
• Calcification of the falx cerebri
• Palmar and plantar dyskeratosis
• Multiple epidermoid cysts (milia) of skin
• Frontal bossing
• Hypertelorism
• Ovarian fibromas
• Medulloblastoma
• Shortened metacarpals

For more watch here

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  Forhead exhibiting frontal bossing with skin "milia"

  
  

  

  Calcification of falx cerebri