A previously well 52-year-old man presented with a 1-month history of a solitary, intermittently mildly pruritic lesion on his back that would recurrently crust. Physical examination revealed a sharply demarcated, adherent, scaly annular lesion surrounding an evenly pigmented lesion with regular borders (Figure 1). An incisional biopsy was performed (Figure 2 and Figure 3).
Yung A, Goodfield MD. An Annular Lesion on the Back—Quiz Case. Arch Dermatol. 2003;139(9):1209-1214. doi:10.1001/archderm.139.9.1209-a