Syphilis presenting as isolated cervical lymphadenopathy: two related cases.

Two young adult brothers, with no apparent risk for sexually transmitted infections (STI), presented with unilateral cervical lymphadenitis. Syphilis was diagnosed by fine-needle aspiration cytology in one case, and subsequent serology and revision of a resected lymph node in the second case. Clinicians should have a high index of suspicion and a low diagnostic threshold in patients with unexplained lymphadenopathy, even in the absence of a history of primary syphilis, or obvious risk for STI.