Neoplasia is a big disease in both humans and animals and can be quite easily diagnosed and is actually well treated.
When testing a lump for neoplasm or other sources, a widely used, simple technique is a Fine Needle Aspirate (FNA). An FNA involves essentially sticking a needle into the mass and squirting the cells onto a slide. this can give you a good idea of the cells in the mass and identif the tumour (not always that useful).
In diagnosing a neoplastic condition you check what are known as the nuclear criteria of malignancy.
1. Anisocytosis and anisokaryosis. The first term relates to cells being of different sizes. As you can see in the pictures above there are barely any of the same size. the second term relates to the size of the nucleus which as you can see again, is varying in the pictures.
2. Mitotic figures. These are essentially catching mitosis. As neoplasms are rapidly dividing masses of cells it’s not uncommon to be able to find them. If you know the process of mitosis you can easily identify the second picture as having a mitotic figure right in the middle. There is also one in the first picture (The elongated nucleus)
3. Multiple nuclei. I sadly don’t have any good photos of those but these are single cells that appear to have more than one nuclei. when you think you see one of these, make sure you notice the cytoplasm and that there is only one with no membranes in between.
4. Multiple prominent nucleoli. These appear as dense (usually basophilic) ‘blobs’ within the nucleus. Again I have no photos of these.
The presence or absence of these criteria often give an idea of the prognosis of the animal.