A slowly enlarging pigmented lesion

A 32-year-old woman consulted for a pigmented lesion on her left arm. This lesion was slowly enlarging for 3 years.

 Dermoscopy revealed:

• an atypical reticular pattern with a total disorganization
• multiple colors
• signs of regression

 Two punch biopsies were performed.
Pathology was in favor of a melanoma in situ.
Lesion was excised with a 0.5 margin.