I guess I should write a bit more about what I actually do for a living since it's a really unsung branch of health care - few know what cytology is - or why it matters.
Take a look at this picture. What you're looking at are cells. Squamous epithelial cells. The word squamous comes from the Latin "squama" meaning scale. I love how that word describes so perfectly not only the cell's form but its function. That happens a lot in biology - form and function being perfectly matched - love that natural selection.
At any rate - these squamous epithelial cells are from the uterine cervix of a human being. Little scales... we are all covered in little scales - cellular scales. You guessed it - these are skin cells. They link together like plate-mail and cover our entire body.
But these aren't just any old skin cells; these are abnormal skin cells. If you've been trained in cytopathology you would recognize this as a low grade squamous intraepithelial lesion, or LSIL, showing HPV effect. How do we know that these cells are abnormal? It's simple really. We know they're not normal because they don't look normal. See how easy that was?
This image here - to the left of this block of text - these are what normal squamous cells look like. See the difference? The nuclei here are much smaller compared to the abnormal ones, the ratio of cytoplasm to nucleus is much higher in the abnormal ones - and notice the cytoplasmic clearing effect that's present in the abnormal cell group? Not present here. See - normal! Easy right? All through the magic of natural dyes and light microscopy. That's how cytology has been done for 100 years. The field has evolved considerably, especially in the last 20 years, with the advent of the HPV test and vaccine. And as AI and imaging software gets better and better, who knows where the field will ultimately end up? But I have a sense there will always be a need for the skilled healthcare profession of Cytotechnology.
