Keratocystic Odontogenic Tumor
The keratocystic odontogenic tumor (KOT) is a benign odontogenic tumor that was formally known as an odontogenic keratocyst (OKC).
The change in the name was done to differentiate this lesion from the more common keratinizing odontogenic cyst and to denote its more aggressive biologic nature.
These tumors can be a small solitary radiolucency or a large multilocular radiolucency. These tumors can also be part of the nevoid basal cell carcinoma syndrome. The pathology is specific for these tumors and a pathologist with experience in identifying these tumors is imperative.
The treatment is typically curettage with or without bone grafting. Wide surgical excision has been recommended in the past. For large tumors, marsupialization has regained favor to reduce the size of the tumor and then curettage or excision.
Here are some examples of keratocytic odontogenic tumors:
- The patient is a 44 year old white male referred to the office for evaluation of a solitary radiolucency of the left posterior mandible. The exam revealed no pain or swelling of the mandible. The panorex revealed the solitary radiolucency with slight diversion of the roots of the mandibular teeth.
The patient had excision of the lesion with bone grafting under local anesthesia in the office. This was found to be a keratocystic odontogenic tumor.
- This patient is a thirteen year old female referred for evaluation of her impacted wisdom teeth and a large unilocular radiolucency of the right posterior mandible. The patient was taken to the hospital, where all four impacted wisdom teeth were removed along with the large cystic lesion. The right mandibular defect was bone grafted. The pathologist reviewed the tissue and along with consultation with an oral pathologist gave a diagnosis of a keratocystic odontogenic Tumor.
- The next patient was first seen as a seventeen year old male with a large radiolucency of the mandible. The biopsy revealed an odontogenic keratocyst, current (keratocystic odontogenic tumor). The conventional treatment at that time was excision of the mandible, but a less aggressive approach of curettage was done for this young man. The patient had multiple root canals prior to the surgery. The patient was taken to the hospital, where the entire mandibular lesion was curetted and the mandible was bone grafted. He has had three additional tumors excised and he was confirmed to have the nevoid basal cell carcinoma syndrome.
These tumors can be difficult to treat as there is a 25 % recurrence rate. Careful follow-up with radiographs is necessary.