[Chancre of the finger. A circuitous route to diagnosis].

A 33-year-old woman presented with a 4-months history of a granulating ulcer on the right index finger. Paronychia was suspected and nail extraction with subsequent histopathologic examination of the removed tissue was performed. Two months later, it became known that the patient's sexual partner had been treated for syphilis. The patient's serology was also positive. Subsequent examination of the original tissue sample by polymerase chain reaction, immunohistochemistry using Treponema pallidum-specific antibodies, and silver staining revealed large numbers of syphilis bacteria, confirming the diagnosis of extragenital chancre.