Sonographic appearance of syphilitic induration mimicking squamous cell carcinoma in the lower lip: a case report

Background Syphilis is a sexually transmitted disease caused by the spirochete Treponema pallidum. Recently, its incidence has been increasing worldwide. We encountered a young woman who presented with induration mimicking squamous cell carcinoma in the lower lip, without major medical conditions. Case presentation A 25-year-old Japanese woman presented with a 1-month history of a painless induration in her lower lip. Because squamous cell...