Various factors -- including 'ugly duckling' -- indicate cancer

[00:00:01] Host Amber Smith: Here's some expert advice from surgical oncologist, Dr. Daniel Thomas, from Upstate Medical University: How is melanoma skin cancer diagnosed?

[00:00:11] Daniel Thomas, MD: Most melanomas are diagnosed either by primary care doctors or dermatologists. And really what they are looking for are what we call the A-B-C-D-E rule. That's looking at a specific pigmented or dark mole and assessing the characteristics of how it works. And our A-B-C-D-E rule is that the mole is asymmetrical, or it's not a perfect circle, or oval.

And the B is the border, if it has what we call irregular borders, and that's if the edges of it aren't kind of confined, it can jut out and have kind of finger-like projections on it. The C is color. If a mole has more than one different color, often, if it's a melanoma, it will be a light brown or maybe a medium brown mole that has an area or two within the mole itself that is much darker, darker brown, or even black.

And then the D is for diameter. Most moles are within the size of about the end of an eraser tip on a pencil, which is about 5 to 6 millimeters. And so when they get larger than that, even in the absence of some of the other characteristics, it's something that many primary care doctors or dermatologists will just keep a close eye on, if not biopsy.

And then the E is evolution, which means that you had this mole, you know it was there, it's been there for years or maybe just a few months, but then you start to notice it changes or evolves. And, really, any change over the course of months to a year or two is something that should probably be brought to attention, because most moles don't change over the course of that short time period. People can have moles their entire life that sure change over many years or decades, but when they change in a shorter interval, it's something to bring up.

And then the last one -- and this one is important for people who have many moles -- is what we call the ugly duckling sign. It's you have a lot of moles and this one that you just noticed doesn't look quite like the others, for one reason or another. People who have a lot of moles, they tend to all look similar and scattered throughout whichever part of their body. But if there's one that just doesn't look like the other, the ugly duckling sign, that's something you should probably bring up as well.

These are usually diagnosed by primary care doctors or dermatologists who are performing thorough skin exams and really keeping track of a patient's moles and skin lesions over the course of many visits so that we can get a good idea of what is changing and what's just staying the same.

[00:03:13] Host Amber Smith: You've been listening to surgical oncologist Daniel Thomas from Upstate Medical University.