A solitary ulcer on the tongue

Summary Syphilis is a systemic sexually transmitted infection caused by the invasive bacterium Treponema pallidum . The diagnosis remains challenging since the disease is labeled as “the great imitator” due to its broad clinical and histopathological appearances. Due to a significant rise in its incidence rates, syphilis should always be considered as a differential diagnosis of any painless, newly developed, oropharyngeal ulcerated lesion. This case demonstrates the rare clinical appearance of a chancre on the tongue as the primary clinical sign of syphilis.