Moles after radiotherapy

This is probably a really daft question but has anyone else who has had radiotherapy worried about moles, i am absolutely covered in dark moles under my breast and on my chest. I didnt have any before and am a little concerned. I know this is probably normal but just wondered whether anyone else has experienced the same. I am 6 weeks post radiotherapy

Is it worth you contacting the radiotherapy department where you had your treatment? I finished my last session today and was told any concerns at all about my skin, in the coming weeks, to call them.
Am sure it is all ok but important you get peace of mind! Let us know the outcome.

I’m 11 days into my 30-day radiotherapy programme and, like you, have had a cluster of moles come up on my breast. The nurse took a look at them today and reassured me that this is perfectly normal. Still going to keep an eye on them though. Right now feeling very, very sore, especially around the nipple.

Lyn - I had a few ‘invisible’ skin tags on my chest and underarms which turned dark like moles after my RT. They faded back to normal in a couple of months. Maybe that’s what happened to you - but check with the RT dept. anyway.

I had suspect mole checked today as I’m finishing rads today and had noticed it changed through chemo… I had to go to GP for him to refer to dermatology, you can’t get referred through onco it seems… All clear with mole, but I would get someone that knows moles to check, not a nurse saying its normal, it might need biopsies taken and they cannot make that judgement just by looking.
Maggie x

I’m through with radiation (3 months ago) and am still a bit tired, have shingles with no blisters above the breast and have lots of tiny dark moles.  Hang in one prepared me for shingles or moles.

<li-spoiler>?hugs to you. </li-spoiler>

I finished yesterday and just noticed a few moles on the underside of my treated boob which I didn’t have before!!! Should I be concerned or is it something that is a normal reaction to rads? Apart from that I’m fine!

Thanks I will keep my eye on it then. If that’s is physically possible!!! Lol!!

Putting my specs on, and looking properly, I have discovered quite an area of small dark moles under the ‘zapped’ boob, a few around the boob, and a mole that I did have is looking slightly wider?  It never occurred to me to consider the implication of radiation and moles/skin changes, when so much advice is given about tanning salons being bad for the skin?  And of course, to get this checked out if we think it is a problem, it means new appointments via GP’s ( sigh ) as it doesn’t fall into the Breast Cancer box.  I finished 20 zaps in early August, and thought I had got off fairly lightly in the side effects  -  now I am wondering?  Any ideas or comments anyone else?

Hello Paulus,


I have the same, especially under the zapped breast, and several areas of dark skin that were not previously there, - one feels actually quite sore (I finished 15 treatments in August.)  On closer examination, it seems to have been a skin tag, I notice that an earlier post on here mentions these? I’m quite fair skinned and these patches are very noticeable and I agree, a bit worrying. I did have several existing moles near the arm pit area, this was also treated - but these do not seem to have been affected, which is weird…

I have an appointment with the Lymphoedema clinic next week, (which in our unit is staffed by radiotherapists) and I will ask about this…





Thank you Thistledown x

I was a bit cheeky and wrote to the lovely lady in charge of my radiology, and told her about my concerns, and she was kind enough to have admin phone me, as well as replying to my email herself, and I have been given an appointment to see her next week.  Totally impressed with generous response, and am hoping that it turns out to be ‘one of those things’ post-radiotherapy.

I have never imagined that this is possible after radiotherapy. Thank you for sharing, I think that this topic will be useful to many on this forum, including me. I remember how half a year ago I finished radiotherapy with great success and the doctor told me that there should be no complications. But I still very often read about it on the Internet on various forums and sites such as It is quite interesting and clear to talk about this problem. If you are interested in learning more about this then you definitely need to read this article