Pigmented skin lesion without biopsy pigment

A 15-year-old male was referred to the dermatology clinic for evaluation of a new pigmented lesion on the right sole that was noticed 1 week prior. He denied pain, bleeding, itch, or preceding injury. Upon further questioning, he endorsed walking barefoot on his driveway, and it was uncovered that his neighbor’s yard contains a black walnut tree. Physical examination of the right heel revealed a poorly demarcated 22 x 14 mm brown patch with an uninflamed, light brown periphery. There was uniform pigmentation on dermoscopy, and the patch was unaltered by alcohol wipe.

source https://www.jpeds.com/article/S0022-3476(21)01234-8/fulltext?rss=yes