Sauer

 
"The classic malignant melanoma is a black or purple nodule, but it may be flat, or pedunculated, and may be pink, red, tan, brown, or black.
 
The changes in a recent or longstanding skin lesion that should arouse suspicion include change in the size or shape, change in pigmentation (particularly the development of pseudopodia or areas of satellite pigmentation), erythema surrounding the lesion, induration, friability with easy bleeding tendency, and ulceration."
 
Sauer GC. Manual of Skin Diseases. 4th Edition. Philadelphia: J.B. Lippincott Company, 1980:290.
 

Brief critique

 
All of the features mentioned by Sauer, namely, nodularity, pedunculation, satellitosis, bleeding, and ulceration are signs of a melanoma that is likely to prove fatal because it already has metastasized. Features that pertain to changes in a lesion can only be learned by history or through photographs taken serially, not from a single examination morphologically by a physician.