Detection of sexually transmitted diseases by urethral cytology, the ignored male counterpart of cervical cytology.

The detection of sexually transmitted diseases by urethral cytology was investigated in 270 men examined by urethral swabbing smears. Each sample was used to prepare a wet mount smear and smears for staining by the Papanicolaou, Gram and methylene blue techniques. A fifth smear was used for direct staining with fluorescein-conjugated monoclonal antibodies for the detection of Chlamydia trachomatis. The smears were examined for cytoplasmic and nuclear changes as well as for pathogenic organisms and inflammatory changes. Infections with Chlamydia trachomatis, Neisseria gonorrhoeae and human papillomavirus (HPV) produced distinctive cytologic patterns similar to those seen in cervicovaginal smears from women. The patterns in candidiasis, trichomoniasis and herpes simplex virus infection were not as diagnostic. Particularly noteworthy were the nuclear alterations, which appeared to be proplastic in HPV infection but retroplastic in Chlamydia infection. The results of this study indicate that urethral cytology would be an invaluable addition in diagnosing sexually transmitted diseases in men, particularly in the case of Chlamydia and HPV infections. The monomorphic structure of urethral columnar epithelium, as compared to the cervical epithelium, seems to result in a clearer and more constant response to pathogenic infections, as seen in the resulting smears.