Multiple Papules in a Localized Area

REPORT OF A CASE  A 16-year-old boy presented to the pediatric dermatology clinic at the University of Miami for evaluation of multiple flesh-colored papules on his right lower back that had first appeared ten years previously and had gradually increased in number. There was no family history of similar lesions or cafe au lait spots and the patient's medical history was otherwise unremarkable.Physical examination revealed a well-developed adolescent with multiple soft, nontender, flesh-colored papules varying from 1 to 8 mm in diameter and confined to the L1 to L2 dermatome of the right lumbar region of the back (Figs 1 and 2). The remainder of the cutaneous examination was entirely within normal limits, and results of an ophthalmologic evaluation were unremarkable.A skin biopsy of one of the lesions revealed a nonencapsulated dermal mass (Fig 3), composed of thin, faintly eosinophilic, wavy fibers with slender, spindle-shaped nuclei whose ends