Amyloid-producing Odontogenic Tumour

Typical Signalment

• This is a common odontogenic tumour in cats.
• More rarely found in dogs.

Description

The lesions appear as masses that are friable and ulcerated. Many amyloid-producing odontogenic tumours are melanotic which makes them difficult to distinguish from the more aggressive malignant melanoma. They can erode but not infiltrate adjacent bone.

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 with mineralization within the mass. Periosteal reaction of the adjacent bone may be visualised. 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

Histologically, the tumour appears to be well demarcated from the surrounding tissue but is not encapsulated.

Treatment

• Surgical excision with narrow margins is normally sufficient.
• Radiation therapy should be considered in cases of incomplete surgical excision.

Prognosis

• Good following complete surgical excision.
• Recurrance following incomplete surgical excision is possible.

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