Benign moles have a more uniform tan, brown, or black color. The border is regular and the lesion is Clinical classification Melanoma either begins de novo or develops from a preexisting lesion, such as a congenital or atypical mole. A classification into several different types was devised after observing that the microscopic Superficial spreading melanoma . SSM is most common in middle age, from the fourth to fifth decade. Nodular melanoma .
NM occurs most often in the fifth or sixth decade.
It is found anywhere on the body. LMM usually presents in the sixth or seventh decade. The radial growth phase may last for years and never develop a vertical growth phase. The risk of progression of LM to LMM varies with age, but is lower than commonly believed. These risk estimates apply to patients in whom LM is discovered incidentally.