Nodular Melanoma

Hello, I forced my dermatologist to take off a mole yesterday. She said there weren't any warning signs but it looked kind of irritated. It's on my back shoulder. Anyway, there are about 4 others that look just like it on my shoulder and they are perfectly round and smooth. They are raised but not nodular. They just raise very slightly to where you have to take an angle at the mirror to see any raising.

My question: She said she would be floored if it came back positive. I said what stage would it be? She said if it was to be melanoma it would be nodular and not superficial because it's perfectly round.

Do nodular melanomas grow vertical above the skin and do they grow more then a very, very slight raise that has to be searched with out using a mirror? Do they raise enough and fast enough ABOVE the skin to be obvious?