Acanthomatous Ameloblastoma

Typical Signalment

• Common oral tumour in dogs but rarely occurs in cats

Description

This is a benign but locally invasive odontogenic tumour that appears in the gingiva, often surrounding and displacing the adjacent teeth. The lesions have a raised and cauliflower appearance and are slow growing. Eventually the lesions can become very large and involve the jaw bone. Acanthomatous ameloblastomas have also been known as acanthomatous epulis, peripheral ameloblastomas, basal cell carcinomas and adamantinomas.

Diagnosis

Clinical Signs

• halitosis
• oral bleeding
• dental disruption or loss
• facial or mandibular deformity
• excessive salivation
• growth protruding from the mouth
• dysphagia occurs rarely

Diagnostic Imaging

Skull radiography may show a soft tissue opacity in the area of the gingiva with lytic invasion of the underlying alveolar bone. If a malignant neoplasm is a dignostic possibility thoracic radiography should be carried out to evaluate for lung metastases.

Biopsy

Required for a definitive diagnosis

• Incisional Biopsy - best
• Cytological or grab procedures - difficult to obtain a representative sample

Treatment

• Surgical resection with margins of at least 1cm.
• Radiation therapy may be considered in patients where wide surgical excision is not possible. However there is a risk of malignant transformation of the tumour at a later stage.

Prognosis

Good following complete surgical excision.

References

• Tutt, C., Deeprose, J. and Crossley, D. (2007) BSAVA Manual of Canine and Feline Dentistry (3rd Edition) BSAVA

• Merck & Co (2008) The Merck Veterinary Manual