Urethra

The urethra takes the urine from the urinary bladder to outside of the body.

It is occasionally afflicited by tumours.

Anatomy

• Proximal portion = urothelium.
• Distal portion = squamous.

Males

• Pre-prostatic urethra - transitional epithelium.
• Prostatic urethra - transitional epithelium.
  • Cancer arising at this site is prostatic urothelial carcinoma.
• Membranous urethra (from apex of prostate to bulb of penis (bulb of the corpus spongiosusm)) - pseudostratified columnar epithelium.
• Spongy urethra - pseudostratified columnar epithelium (proximal) & stratified squamous (distal).

Pathology

• Squamous cell carcinoma.
• Urothelial carcinoma.
• Prostatic carcinoma - may have pseudopapillae and mimic urothelial carcinoma - see urothelial carcinoma-like prostatic carcinoma.
• Clear cell adenocarcinoma of the urethra - similar to clear cell carcinoma of the gynecologic tract.
• Urethral caruncle.

See also

• Urethra in males.
• Urothelium.