A 16-year-old boy with asymptomatic, hyperpigmented, hairy lesion on his left upper back. The pigmentation, first noted 5 years earlier, had progressively spread across his torso. The coarse and dark hair confined to the hyperpigmented area had appeared at age 13 years. Medical history uneventful. Review of systems showed no abnormalities. No family history of similar skin lesions.
Large, segmental, well-demarcated, irregularly margined, brownish patch with hypertrichosis on the left lateral, upper back. Remaining physical findings unremarkable.
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