I am attempting to reply, but having difficulty as I am new to this forum. In any case had a biopsy yesterday on my big toe left foot for probable melanoma. It is rare in caucasian people. I have never been one to follow any typical type of diagnosis! Had a malignant melanoma on right thigh 40 years ago and have been melanoma free until this recent occurrence of a vertical brown stripe on big toe. No clue how long its been there as most folks don’t spend a lot of time looking at toes. At least I don’t. In any case its extremely rare and there is a good chance you will be OK, but get it checked out. My doctor is very sure it is melanoma, but was using words we all want to hear “in-situ. I’ll keep you updated.