Hi, I've just had a cryo treatment (liquid nitrogen) done on a patch of sun damage on my face, the blister is about three quarters of an inch in circumference. I now live in SW France and always use total sunblock, but I spent my teenage years growing up in Florida, and at the time we used suntan oils, not sun blocks. As a result, the previous dermatologist said 5 years ago that my damage was what he'd expect to find on an 80-year-old, and I'm 39. Anyway, I went to the Dr as the patch started itching a few months ago, and I noticed that it was also thickening, from just a coloured darker mark to something thicker in the center. From what I could find on the internet, it looked to me very similar to the photos of lentigo malignas and lentigo maligna melanomas, and I was getting worried as they said that the transition point to malignancy is when the area starts growing, itching and/or moves to a vertical thickening, all of which it had done. I should add that the Drs here are pretty arrogant and bad at explaining what their diagnosis is, in general- I had 1 GP assure me that there was "absolutely no doubt" that it was nothing at all- not really consistent with the dermatologist's assessment that it was pre-cancerous and needed to be removed immediately... But that is the problem- everything I read seemed to say that these particular types of melanomas were really hard to identify, even to dermatologists, that is, to distinguish from non-cancerous marks, unless they were actually biopsied. Yet this guy just said, right, I'm going to freeze it off, all he did was look at it under a magnifying glass, and went ahead right then and there- no biopsy, no discussion about the treatment options. In retrospect I wish I'd refused and insisted he discuss it with me first, but I felt embarrassed about questioning him, and second-guessing his expertise. So here's the root of my question- if he was right and it's just pre-cancerous, no trace of melanoma, then there's nothing to worry about. BUT if he's wrong, and has frozen something that potentially had parts in it that were malignant, and it was thickening, etc, how would I know he got it wrong and what would I look for, post-treatment? I have been wondering if I could somehow send the blister caused by the freezing process off to a lab for testing, when it falls off, as it would, I'm guessing, still have the melanoma cells, if there are any, in it- but I am totally ignorant about whether the cells remaining in the blister would still be identifiable after having been frozen and turned into a hard blister, as cancerous or non cancerous? Has anyone had this experience? I'd be really grateful for any thoughts or suggestions. Thanks!!