Mast cell tumours (MCTs) are the most common cutaneous tumours of dogs, however rarely they can arise from the oral mucosa. This subset of MCT is reported to demonstrate a more aggressive clinical course than those tumours on the haired skin and the authors hypothesised that dogs with oral, mucosal MCT would have a high incidence of local lymph node metastasis at presentation and that this would be a negative prognostic factor. An additional hypothesis was that mitotic index (MI) would be prognostic.
This retrospective study examines 33 dogs with MCTs arising from the oral mucosa. The results suggest that oral mucosal MCTs in the dog have a high incidence of lymph node metastasis at diagnosis (55 per cent) which results in a poor prognosis. MI and nodal metastasis is highly prognostic. Loco-regional progression is common in these patients and dogs with adequate local control of their tumour had an improved outcome. Despite a more aggressive clinical course, treatment can result in protracted survivals, even when metastasis is present.
The study is from the Department of Veterinary Clinical Science, Liverpool University, Liverpool, UK; Small Animal Teaching Hospital, Liverpool University, Liverpool, UK; Oncology Unit, Animal Health Trust, Newmarket, UK; CSAS, Animal Health Trust, Newmarket, UK, and Small Animal Hospital, University of Glasgow, Glasgow, UK.
Elliott JW, Cripps P, Blackwood L, et al. Veterinary and Comparative Oncology 2016; 14 (1): 101-111; doi: 10.1111/vco.12071