Hairy Brownish Patch

February 3, 2015

This asymptomatic, hyperpigmented lesion was first noted 5 years earlier on the left upper back of a 16-year-old boy. A nevus? Cafe au lait spot?

This asymptomatic, hyperpigmented, hairy lesion is on the left upper back of a 16-year-old boy. The pigmentation was first noted 5 years earlier; the coarse and dark hair confined to the hyperpigmented area had appeared at age 13 years. History and physical examination findings were unremarkable.

What’s your diagnosis?