Linear unilateral basal cell nevus with comedo-like lesions.

A 20-year-old woman had linear unilateral basal cell nevus with comedo-like lesions. Numerous papules were distributed on the left side of the upper aspect of the trunk in a zosteriform fashion. The indivisual lesions were hemispherical, pearly, and waxy tumors, some of which had central plugs. Histologic examination revealed polymorphous patterns that suggested that the tumor cells differentiated toward the apocrine glands, hair structures, and sebaceous glands. Ultrastructurally, the tumor strands were composed of fairly mature basal cells with well-developed tonofilaments and desmosomes.