Calcifying Epithelial Odontogenic Tumour

Calcifying epithelial odontogenic tumour is a rare benign but locally invasive epithelial odontogenic tumour. It makes up about 1% of odontogenic tumours.

It affects adults between 20 and 60 years of age, with a mean near 40, equally in men and women. About two thirds are in the mandible, mostly in the premolar and molar region, and half are linked to an impacted tooth.

Pathophysiology. The tumour consists of sheets and islands of polyhedral epithelial cells with eosinophilic cytoplasm, distinct intercellular bridges and pleomorphic nuclei, in a fibrous stroma.

It produces amyloid like material that stains with Congo red and shows apple green birefringence, and this material becomes calcified in concentric rings (Liesegang rings). Despite nuclear atypia, behaviour is benign.

A slow, painless swelling of the jaw, with tooth displacement and delayed eruption. Some lesions are found on radiographs. Pain and paraesthesia are unusual, and the overlying mucosa is intact. Peripheral lesions are rare.

Rapid growth, ulceration, numbness or mobile teeth suggests a more aggressive tumour.

• Panoramic radiograph: a unilocular or multilocular radiolucency with radiopaque foci of various size, often related to the crown of an impacted tooth (a driven snow pattern in some).
• Cone beam CT or MRI: extent, cortical perforation and relation to the inferior alveolar canal and sinus.
• Incisional biopsy before definitive surgery, with histology and Congo red staining.
• Staging imaging only when malignancy is suspected.

Differential diagnosis.

• Adenomatoid odontogenic tumour
• Calcifying odontogenic cyst
• Ameloblastoma
• Ameloblastic fibro odontoma and odontoma
• Dentigerous cyst
• Odontogenic myxoma
• Osteosarcoma and cementoblastoma
• Ossifying fibroma

• Surgical removal with a margin: marginal or segmental resection with a 0.5 to 1 cm margin of normal bone for tumours of significant size and the mandibular tumours with cortical perforation, with reconstruction as needed. Conservative enucleation or curettage is used only for small, well circumscribed lesions.
• Recurrence is about 10 to 15% overall and is higher after enucleation (up to 15 to 20%) than after resection (under 5%), with figures of lower certainty.
• Extract associated impacted teeth when involved in the resection.
• Antibiotics only for infection with spread: amoxicillin 500 mg orally three times daily for 5 days (reduce to 500 mg every 12 hours at eGFR 10 to 30), or clindamycin 300 mg four times daily in penicillin allergy.
• Analgesia: paracetamol 1 g every 6 hours (maximum 4 g daily) with ibuprofen 400 mg every 8 hours with food.

Monitoring. Review every 6 months for 2 years, then annually for at least 5 to 10 years, with radiographs.

Referral and escalation. Refer to oral and maxillofacial surgery for biopsy and planning. Urgent referral for rapid growth, cortical destruction or recurrence.