Answer to Image Challenge

The answer to yesterday's image challenge is.....drumroll.....

#1  Congenital nevus.

The skin in this region of the boy's scalp was lightly pigmented, with dark hairs; the lesion had been more pigmented at birth.  A congenital nevomelanocytic nevus was diagnosed.  Such nevi are often present at birth but can develop later in life.  Biopsy or excision is often done since they can transform into