Syphilis
The presentation of a painless genital ulcer with non-tender (rubbery) lymphadenopathy is characteristic of primary syphilis. The primary chancre of syphilis is: 1) Painless, 2) Single (usually), 3) Indurated with clean base, 4) Associated with non-tender, rubbery, bilateral inguinal lymphadenopathy. In contrast: Chancroid causes painful ulcers with tender lymph nodes, Herpes causes painful vesicles/ulcers, and Granuloma inguinale causes painless ulcers but with pseudobuboes (subcutaneous granulomas) rather than true lymphadenopathy.