Background

An epidemic of infectious syphilis has emerged worldwide among men who have sex with men (MSM), a condition with myriad manifestations and one that frequently eludes clinicians. Current common diagnostic methods rely on the laboratory detection of antibodies to Treponema pallidum and cardiolipin, the use of dark field microscopy and clinical acumen. Molecular tests are becoming available but are less useful for non-mucosal lesions. We report a recent case of syphilis mimicking a lymphoproliferative disorder where a unifying diagnosis only became apparent when a novel but underused test was employed: the spirochaete immunostain.