Multiple Flesh-Colored Nodules: A Patient with Multiple BAP 1-Inactivated Melanocytic Tumors.

Abstract

A 22-year-old man without previously known skin disease presented with multiple asymptomatic, skin-brown to red-brown papules on the head and neck for 1 year (Figure 1). The diagnoses considered included benign intradermal or compound nevi, atypical nevi, and neurofibromas. Shave biopsies of three lesions revealed intradermal melanocytic lesions comprising large epithelioid melanocytes flanked by small banal melanocytes (Figure 2). All nevi had a low proliferation index, absent junctional component as demonstrated by a dual Ki-67/Mart-1 immunostain, and no dermal mitotic figures. Immunostaining demonstrated lesional melanocytes positive for p16, but the larger epithelioid melanocytes in these lesions lacked nuclear expression of ubiquitin carboxyl-terminal hydrolase protein (BAP-1; Figure 3). The diagnosis of a BAP-1-inactivated nevus was made, and the patient was referred for genetic counseling and screening for associated malignancies. Given that the lesions involved deep margins, the same were completely excised.