Right Buttock Rash for Thirty Years in a Patient from China

Question: A 57-year-old man who emigrated from mainland China to the United States 2 years ago presented with a plaque on his right buttock that had been there for ≤30 years. He noted that the lesion developed shortly after sitting on a nail. He had intermittently sought care for the eruption, which included oral antibiotics for several months and multiple excisions. Neither of these interventions resulted in a cure, although the lesion had regressed from its maximal involvement of the buttock and upper posterior thigh. He was a long-time smoker with a medical history significant only for asthma, for which he received inhaled albuterol. In China, he worked as a salesman. Physical examination revealed a well-nourished middle-aged man in no distress. On his right buttock was a 15 × 13 cm exophytic fungating plaque with a linear keloid centrally and peripheral crusting. Inferiorly, postinflammatory hyperpigmentation was visible over the upper thigh (figure 1A). His laboratory studies and findings of the remainder of examination were unremarkable. Diagnostic punch biopsies were obtained for histopathologic evaluation and culture. Figure 1 Question