Odontogenic keratocyst

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Odontogenic keratocyst
Diagnosis in short

Keratocystic odontogenic tumour. H&E stain.

Synonyms odontogenic keratocyst (old term)

LM stratified epithelium with "ribbon-like appearance" with palisaded basal cell layer, parakeratosis, artefactual separation of epithelium from the basement membrane
LM DDx odontogenic cyst (dentigerous cyst), squamous cell carcinoma
Site usually mandible - see odontogenic tumours and cysts

Syndromes nevoid basal cell carcinoma syndrome

Signs mass lesion
Prevalence uncommon
Clin. DDx ameloblastoma
Odontogenic keratocyst
External resources
EHVSC 10179 10178
Wikipedia keratocystic odontogenic tumour
Pathology Outlines topic/mandiblemaxillakeratocyst
Rosai Collection 14023

Odontogenic keratocyst, abbreviated OKC, is an uncommon odontogenic cyst.

It was known as keratocystic odontogenic tumour, abbreviated KOT, from 2005 to 2017.[1][2]




  • Most common presentation: swelling.


  • Location: usually mandible.
  • May mimic ameloblastoma radiologically.


Features: [6]

  • Stratified epithelium (resembling squamous epithelium) with:
    • "Ribbon-like appearance" - important.
      • Typically 8-10 cell layers thick - with relatively uniform thickness.
      • Lacks rete ridges.
    • Palisaded basal cell layer.
  • Parakeratosis (keratinized cells with nuclei) - key feature.
  • Artefactual separation of epithelium from the basement membrane.




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Right Maxillary Sinus Mass, Excision:
     - Consistent with odontogenic keratocyst (benign ribbon-like squamous epithelium
       with keratinization, separated from the underlying hyaline stroma with cartilage).
     - Benign respiratory mucosa with mild inflammation.
     - NEGATIVE for malignancy.

See also


  1. Madras, J.; Lapointe, H. (Mar 2008). "Keratocystic odontogenic tumour: reclassification of the odontogenic keratocyst from cyst to tumour.". J Can Dent Assoc 74 (2): 165-165h. PMID 18353202.
  2. El-Naggar, Adel K, ed. (2017), WHO Classification of Head and Neck Tumours, WHO/IARC Classification of Tumours, 9 (4th ed.), Lyon, France: IARC Press, ISBN 978-92-832-2438-9, http://publications.iarc.fr/Book-And-Report-Series/Who-Iarc-Classification-Of-Tumours/Who-Classification-Of-Head-And-Neck-Tumours-2017.
  3. Lee, JW.; Gates, R.; Wignall, A. (Aug 2011). "Squamous cell carcinoma arising from a keratocystic odontogenic tumor.". Otolaryngol Head Neck Surg 145 (2): 356-7. doi:10.1177/0194599811399270. PMID 21493332.
  4. Tan, B.; Yan, TS.; Shermin, L.; Teck, KC.; Yoke, PC.; Goh, C.; Balakrishnan, A.. "Malignant transformation of keratocystic odontogenic tumor: Two case reports.". Am J Otolaryngol 34 (4): 357-61. doi:10.1016/j.amjoto.2013.01.002. PMID 23374486.
  5. Habibi, A.; Saghravanian, N.; Habibi, M.; Mellati, E.; Habibi, M. (Sep 2007). "Keratocystic odontogenic tumor: a 10-year retrospective study of 83 cases in an Iranian population.". J Oral Sci 49 (3): 229-35. PMID 17928730.
  6. Thompson LDR. Head and neck pathology - (Foundations in diagnostic pathology). Goldblum JR, Ed.. Churchill Livingstone. 2006. ISBN 0-443-06960-3.
  7. Macdonald-Jankowski, DS. (Dec 2010). "Orthokeratinized odontogenic cyst: a systematic review.". Dentomaxillofac Radiol 39 (8): 455-67. doi:10.1259/dmfr/19728573.
  8. URL: http://www.sciencedirect.com/science/article/pii/S0968605305000992#fig5. Accessed on: 11 March 2013.