Practical Review of Common Skin and Subcutaneous Tumours in Dogs and Cats

Skin and subcutaneous masses are the most common tumours seen in dogs, and sec- ond most common malignancy in cats. 20-40% are malignant in dogs and 50-60% are malignant in cats. the top 5 canine cutaneous tumours are mast cell tumours, perianal adenoma, lipoma, sebaceous adenoma and histiocytoma. in the cat it is basal cell tumour, mast cell tumour, fibrosarcoma, squamous cell carcinoma and sebaceous ade- noma. the key features of many of these masses will be covered during the lecture.

It is important that the veterinary surgeon be familiar with the individual tumor types as tumor identity impacts many aspects of case management. in general, carcinomas metastasize via the lymphatic system and sarcomas via the haematogenous route. How- ever, the two vascular systems are connected by lymphovenous communications and there are exceptions to these patterns. a strong knowledge base enables the clinician to perform thorough physical examinations and educate the client about tumour behav- ior, prioritise important staging tests, and choose the type of resection required for cure and long-term prognosis.

In the approach to case management there are two important considerations: 1) whether to obtain a pre-operative biopsy and 2) the extent of pre-operative staging. Staging will vary depending on tumor type but typically consists of thoracic radio- graphs and aspiration of regional lymph nodes. it is important to understand that a lack of lymph node enlargement does not mean that nodal metastasis has not occurred. [...]