Segmental distribution of nodules on trunk

A 70-year-old Caucasian man presented with a longstanding history of numerous nontender, fleshy, skin-colored papules on his trunk, ranging from 3 to 8 mm in size. They were noted incidentally during an examination of unrelated nonhealing lesions on the patient's left cheek. He said the lesions on his trunk first appeared when he was 28 years old and had continued to grow in size and number. The patient said his son had at least one similar lesion on his upper back, but otherwise there was no family history of these lesions. A biopsy was performed on one of the nodules. WHAT IS YOUR DIAGNOSIS? HOW WOULD YOU TREAT THIS PATIENT?