Malignant melanoma

Note the different shades (3 or more) in the same lesion. Also note the irregular (jagged)  edges of the lesion. At the 11:30 position, note the small lesion that looks almost like a separate lesion (satellite). It is seen better in the photo below (same lesion).  The above bolded features are key in helping one diagnose a melanoma.
Depth (Clarke's level) of the lesion is the single most important prognostic indicator.

Excision biopsy ASAP (out-patient) should be done.