Odontogenic keratocyst

by Jason Wasserman MD PhD FRCPC
November 23, 2023

An odontogenic keratocyst (OKC; also known as a keratocystic odontogenic tumour) is a benign (noncancerous) growth involving the bones of the jaw (the maxilla and mandible). It is considered a developmental abnormality because it arises from cells left over from the development of the teeth.

Can an odontogenic keratocyst turn into cancer over time?

No. OKC is a benign growth that will not change into cancer over time. However, the cyst can grow back if not removed completely during surgery. In addition, patients with the genetic condition nevoid basal cell carcinoma syndrome may develop more than one OKC.

What are the symptoms of an odontogenic keratocyst?

Symptoms of OKC include:

• Swelling: You might notice swelling or a bump in your jaw.
• Discomfort or Pain: There can be some pain or discomfort, especially if the cyst becomes large and starts putting pressure on surrounding tissues.
• Tooth Displacement: The cyst can move nearby teeth, causing changes in your bite.

What causes an odontogenic keratocyst?

Most OKCs arise as a result of groups of cells left over from the development of the teeth growing and building up fluid in a central open space called a cyst. Patients with nevoid basal cell carcinoma syndrome are at higher risk of developing one or multiple OKCs. Mutations in a gene called PTCH1 have been identified in patients with and without a genetic syndrome which suggests that this alteration is important for the growth of OKCs.

What does an odontogenic keratocyst look like under the microscope?

When examined under the microscope an OKC shows specific microscopic features. First, it is a cyst, an open space filled with fluid or other material. The inside wall of the cyst is lined by an epithelium made up of squamous cells. At the bottom of the epithelium is a row of small dark cells called basal cells which pathologists describe as palisading. The surface of the epithelium is covered by a thin wavy layer of keratin that is often described as parakeratotic and corrugated. Below the epithelium, the wall of the cyst is composed of connective tissue that may show signs of fibrosis and chronic inflammation, especially if the cyst has previously ruptured.

About this article

This article was written by doctors to help you read and understand your pathology report. Contact us if you have any questions about this article or your pathology report. Read this article for a more general introduction to the parts of a typical pathology report.

Other helpful resources

Atlas of Pathology