Malignant melanoma Breslow's 0.6 mm, with regression
When you look at a red octagonal street sign, you immediately know what it is and what it signifies. The same should apply any time you see a lesion like this. Not many things scare me. I'm not afraid of spiders, snakes, or heights but I am afraid of anything that looks like this. The thundercloud gray to pink look in the center of what can only be a melanoma means only one thing: Regression.
As you know, regression means that the lymph node has already gotten a taste of the melanoma, even though it is not very thick, and the lymph node then mounted an attack on the primary lesion. Even in the case of a non-palpable node, it is a metastatic problem from the moment regression is evident. Will the metastasis kill the patient? Maybe, maybe not, but nevertheless it is there.
All of you recognized this was a melanoma, but if you did not mention regression, you did not get full credit for this answer. When you see a lesion like this, check their nodes and think about SLNBx and heme-onc referral.