A unilateral slow-growing yellow nodule of the glans penis

A 54-year-old man presented with a slow-growing yellow nodule on the glans penis. Histology revealed a dense nodular infiltrate throughout the entire dermis, composed of a predominance of large mononucleated histiocytes with a few multinucleated cells; the overlying epidermis was slightly hyperplastic. The cells were positive for CD68 and negative for S100 and CD1a.