Findings:

1. Dilation of the posterior urethra behind anterior urethral stricture.
2. Filling of the para-urethral glands; small cavities 1-2 mm in diameter alongside the urethral lumen.
3. Filling of Cowpers glands and ducts; the paired Cowper's glands and ducts are seen as narrow channels arising from the posterior part of the bulb of the urethra and diverging from the midline as they pass backwards.
4. Filling of dilated prostatic ducts
5. Bladder diverticula and increased trabeculation because of outlet obstruction.

Discussion: Gonococcal urethritis in males has an incubation phase of 2-6 days following exposure (sometimes longer). N. gonorrhea proliferates on columnar epithelium. It is an ascending infection which establishes itself in the peri-urethral glands.

During the acute phase purulent urethral discharge, dysuria and frequency are noted. Appropriate antibiotic therapy is usually sufficient to clear infection. 10-20% for males remain asymptomatic. Untreated cases resolve in 8 weeks on average. Stricture occurs in untreated and asymptomatic individuals who don't seek treatment.

Since antibiotic therapy is so effective, associated problems are now rare. These included epididymitis, inguinal lymphadenitis, edema of the penis due to dorsal lymphangitis or thrombophlebitis, periurethral abscess or fistula, cowperitis and seminal vesiculitis.

The strictures may be single or multiple and involve the anterior (penile) urethra. Complete examination should include injection retrograde urethrography and voiding cystourethrogram. Small stricture can be easily missed on retrograde urethrography. If catheterization is possible the voiding study readily demonstrates strictures because of dilation of the posterior urethra behind the strictures. Fistulas, filling of paraurethral glands, Cowper's ducts and glands, prostatic cavities, ejaculatory ducts and seminal vesicles when present are also better visualized during voiding studies.

Differential diagnosis of strictures of the anterior urethra include gonococcal or syphylitic infections. While posterior urethral strictures can be caused by gonococcus, tuberculosis, Schistosoma haematobium, or nonspecific infections.

References:

1. Harrison's Principles of Internal Medicine, 7th Edition. 788-791.
2. Witten, Myers, Utz. Emmett's Clinical Urography. W. B. Saunders, 1977;1152-1156.
3. Sutton D. Textbook of Radiology. Churchill Livingstone, New York; 1973:942-944.
4. Davidson J, Hartman DS. Radiology of the Kidney and Urinary Tract 2nd edition.
   W.B. Saunders Co., Philadelphia; 1994:649-657.