Treponema pallidum — The Great Imitator
A 50-year-old woman was admitted to the hospital with swelling of the left lateral malleolus after an ankle sprain and rupture of the Achilles tendon. The physical examination was notable for ulcerated lesions on the left breast, with sanguineous secretions (Panel A), as well as similar skin lesions on the back and left shoulder (Panel B). These findings prompted both gynecologic and dermatologic consultations. The consultants independently agreed that breast cancer was an unlikely diagnosis. The patient reported that the lesions had been present for many years and had not responded to local treatment. Her social history was notable for a period of homelessness 10 years earlier, during which she had had several sexual contacts. Treponema pallidum hemagglutination testing showed a titer of 1:20,480, and a T. pallidum particle agglutination assay performed on a cerebrospinal fluid sample was positive. Tertiary syphilis was diagnosed, and the patient was treated with high-dose penicillin. The ulcerating skin lesions resolved quickly after antibiotic treatment. The ruptured Achilles tendon was treated with surgical reconstruction.