Liz Buchanan BVSc MRCVS
Hello! The trouble with lumps is, that size and colour and even feel do not necessarily reflect what cell type is inside them. This, for example, might be filled with blood from a bleed under the skin - a haemotoma, which would have me worrying about blood-clotting and such but could also result from normal trauma / injury. But it could, just as easily be a tumour. Your vet will check more carefully for clues but may decide to test a few cells (make sure you understand the limitations of this) or the whole lump (more reliable), or even the blood. We're pleased that you have an appointment to see them and discuss this one in detail.