The appearance of lesions on our skin that appear quite quickly and without any apparent reason may be a cause for concern.
They can (like moles) be an indicator of potential skin cancer or other issues. So if you notice them on your own skin then don’t ignore them.
So, in summary: your skin is the most visible part of your body, and is therefore likely to be where you’ll first notice potential health issues. Don’t get paranoid, but do keep an eye out for any potential symptoms, and keep yourself healthy.