From personal experiences I can say pay no mind to images on the internet in regards to what a melanoma looks like. I spent months obsessing about it and convinced myself that I had it. I had two moles removed that fit the description perfectly and they came back fine after tested. That does not mean you should not have abnormal moles looked at because you should but in the waiting dont panick because its not uncommon for a perfectly normal mole to appear cancerous.
Hi,
From the post it looks like you are talking about a halo nevus which it is a melanocytic nevus that develops a surrounding circle of depigmentation. It is not a melanoma but you have to keep an eye on it. Melanomas are usually >6 mm in size, with irregular borders ,asymmetrical and dark in color. If you notice changes in the mole's/mark’s color, height, size or shape, you should have a dermatologist evaluate it. You also should have it checked if it bleeds, oozes, itches, appear scaly, or become tender or painful.Otherwise it should be left as such.
It is very difficult to precisely confirm a diagnosis without examination and investigations and the answer is based on the medical information provided. For exact diagnosis, you are requested to consult your dermatologist. I sincerely hope that helps. Take care and please do keep me posted on how you are doing.