Oral melanoma in dogs: how to stage it
11-year-old Cocker Spaniel with a 2.5 cm pigmented mass on the maxillary gingiva, confirmed as oral melanoma on biopsy. The mandibular lymph nodes are normal in size and consistency on palpation.
What is appropriate staging before planning treatment?
chevron_right Show answer and explanation
A. Cytology of the mandibular nodes even if normal (ideally also the medial retropharyngeal nodes), thoracic imaging and head CT to plan surgery
Correct. Oral melanoma staging includes the regional node (aspirate or excision), the thorax and local bone extension, best defined by CT. Lymphatic drainage may go to nodes on both sides.
B. No staging is needed: if the nodes are normal there are no metastases and surgery can go ahead
Node size does not predict metastasis in oral melanoma: normal nodes can be invaded and enlarged nodes may be merely reactive.
C. Thoracic radiographs only, since oral melanoma metastasises almost exclusively to the lung
The regional node is a common, often the first, metastatic site. Assessing only the thorax understages the disease.
D. Excisional biopsy of the mass with narrow margins and stage only if it recurs
Oral melanoma is locally invasive and metastatic: narrow-margin surgery recurs, and staging afterwards prevents treatment planning.
lightbulb Key takeaway
In oral melanoma, palpating the node is not enough: it must be sampled. Tumour size (<2, 2–4, >4 cm), nodal involvement and metastases define stage and prognosis. Local treatment is wide-margin surgery or radiotherapy.
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Updated: October 31, 2026 · Educational content for veterinary professionals. It does not replace current clinical guidelines or the judgement of the attending veterinarian.