Mast cell tumour

My dog has recently had a MCT removed which came back as low grade two and no further treatment was needed. However, I then found more lumps on him and he had another surgery to remove these. At the time of surgery I mentioned to my vet about a spot on his head he’s had for over 3 years which we’ve been told is likely a sebaceous cyst multiple times. My vet proceeded to remove this anyway due to his breed (pug) being prone to multiple MCT and I’ve now received histology results that it was infact a MCT which again is grade two. I am currently still awaiting results of ki67 tests to find out more about it but my question is would the delay in having this removed and the fact he’s had it for 3 years give it a higher chance of spreading elsewhere in his body? He’s showed no symptoms of being unwell over this time but I’m now worried that the misdiagnosis would have given it time to spread.  Would time allow a low grade MCT to spread or would the fact it’s low grade mean it’s unlikely to spread regardless of how long is been on their body?

Hello - this is a good question for the pathologist who is dealing with the lump when you get the results, as they are the experts when it comes to classifying or predicting the behaviour of lumps and a lot of new knowledge about the behaviour of Mast Cell tumours has come to light in recent years.  They should be able to tell you, for example, whether the MCT in question extended past the edges of the lump.  Please will you let us know what is found?

MCTs can now be treated using chemotherapy, so this is another option worth skimg your vet about.

Hello. One lump came back as a high grade two and I’m absolutely devastated. I am now awaiting a referral to an oncologist for staging. One question though, does a Ki-67 of over 1.8% mean my dog only has months left and this is what I’m reading online