The umbilications or depressions are unique characteristics of
molluscum. If this is present ,then
molluscum is highly probable.
Molluscum does present atypically .They may present as single large nodules or they may develop a stalk.
"Atypical lesions may resemble comedones, abscesses, furuncles, condylomas, syringomas, keratoacanthomas, basal cell carcinomas, ecthymas, sebaceous nevi of Jadassohn, and cutaneous horns .