Answer to Image Challenge
#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 melanoma.
These are often called "birthmarks" and can be found on all parts of the body. Because this was on the scalp it affected the hair growth within the nevus. Many of these birth nevi regress and shrink with age.
Thanks for playing. I hope you learned something.