Liz Buchanan BVSc MRCVS
Keymaster
I should recap the nature of a Fine Needle Aspirate here. A needle is put into a lump at random and a few individual cells are pulled out. This is useful because you can see what some of the cells are (eg mast cells); it is also fairly non invasive, easy and inexpensive. It can be done quickly in a consultation. Usually the needle is put in a few times (or a few different needles or to different depths) to retrieve cells from different places in the lump. This would be a bit like a giant reaching down onto the world, picking up houses from different places in the UK and looking at them under a giant microscope. The giant could then say 'look -these houses are made mostly of brick and have furniture in them. People are here. Sometimes they form towns or cities, so it might be interesting to look more closely.' To continue the analogy, a clinician can say 'look - there are a lot of Mast cells. Often these form tumours, so it's worth my while taking notice.'
Unfortunately, what the giant wouldn't learn from just a few random houses (cells), is what sort of civilisations the people have here - for that, they may need to know how the houses in the UK are arranged - in streets and rows, with cities joined by major roads. They would have to take a slice of the country away in order to learn more about this. What the vet doesn't learn is the shape of the mast cells within the lump; how they are sitting, how invasive or worrying they are. This can be central to grading a lump.
It is true that a biopsy may tell a vet far more information about the layout of the mast cells than an FNA and be more useful in grading the tumour, but it is also more invasive and expensive, requiring a general anaesthetic. It is therefore common for clinicians perform FNAs first in order to give them a rough idea of whether a biopsy or indeed, a full removal, is worth pursuing.
It sounds as though you and your vet need to decide between you how to make the most use of the resources and information that you now have and for this, more communication is probably needed. Please do ask them questions about their gut feelings and about the timescales and prognoses (likely outcomes) involved.
Report