Urethra

21 May 2003, © 2002-2003 PathologyOutlines.com, LLC

Excludes prostatic urethra (see prostate)

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Table of contents - Urethra

 

Primary references

Inflammation, tumors-benign, carcinomas, clear cell carcinoma. melanoma

 

Primary references

AJCC Cancer Staging Manual (6th Ed)

American Journal of Clinical Pathology (AJCP), Jan 1997 to Nov 2002 (no photos)

American Journal of Surgical Pathology (AJSP), Jan 1997 to Nov 2002

Archives of Pathology and Laboratory Medicine (Archives), January 1997 to Nov 2002

Human Pathology (Hum Path), Jan 1997 to Oct 2002

Modern Pathology (Mod Path), Jan 1997 to Nov 2002

Robbins Pathologic Basis of Disease (6th Ed)

Rosai, J:  Ackerman’s Surgical Pathology (8th Ed); Mosby-Year Book, Inc., 1996

 

Please refer to these primary references for more detailed discussions and photographs

 

Urethra

Urethra-normal

Males: consists of mucosa, submucosa, surrounding corpus spongiosum

Meatal and parameatal urethra lined by squamous epithelium; penile and bulbomembranous urethra lined by pseudostratified or stratified columnar epithelium; prostatic urethra lined by urothelium

Distal to prostate are scattered islands of stratified squamous epithelium and glands of Littre’

 

Females: epithelium supported by connective tissue, surrounded by longitudinal smooth muscle continuous with bladder

Urethra continuous with vaginal wall

Distal 2/3 lined by squamous epithelium, proximal 1/3 lined by urothelium

Skene’s glands are concentrated near meatus but found throughout its length

Periurethral glands lined by pseudostratified and stratified columnar epithelium

 

Urethra-inflammation

Urethritis: gonococcal or non-gonococcal

Associated with prostatitis and cystitis

 

Nephrogenic (mesonephric) adenoma

Metaplastic change, not neoplastic, common in urethra

Similar to lesions in bladder neck

 

Non-gonococal urethritis

E coli, Chlamydia trachomatis, Ureaplasma urealyticum

Part of Reiter syndrome (urethritis, conjunctivitis, arthritis)

 

Prolapse

May occur in childhood and simulate a neoplasm

 

Urethral tumors - benign

 
Caruncle

Resembles small raspberry protruding from external urethral meatus

Extremely painful

Bleeds easily, may become infected

Only in female urethra

Considered a reactive polypoid lesion

Often recurs, perhaps due to persistence of inciting factors

Treatment: excision

Micro: highly vascularized fibroblastic connective tissue with chronic inflammation, dilated blood vessels, hyperplastic epithelium

DD: carcinoma

 

Leiomyoma

Relatively common in women, rarely (<10 reported) in men

Case report in 48 year old man with quadriplegia, Archives 2000;124:302

 

Papillomas

May be viral

 

Urethral carcinomas

Rare, more common in women than men

Often elderly women around external meatus, often associated with urethral diverticula

In men, associated with chronic strictures

Presents with bleeding and dysuria

May be warty/papillary, often HPV+

Often ulcerated

Usually squamous cell

50% of tumors arising in urethra diverticula are adenocarcinoma or clear cell carcinoma

More aggressive than bladder cancers (5 year survival 41%); death in a few years from local growth

Metastases to lung, liver, bone

Treatment: radiation therapy, possibly surgery

 

Clear cell carcinoma

Usually women, mean age 58

Similar clinical presentation to other urethral carcinomas

No association with endometriosis

Gross: often (56%) arises within a urethral diverticulum

Micro: similar to clear cell adenocarcinoma of female genital tract; tubulocystic, papillary, and diffuse patterns; hobnail and flattened cells, cells with abundant clear cylasm; moderate to marked nuclear pleomorphism; frequent mitotic figures

DD: nephrogenic adenoma

Negative stains: PSA, PAP

Reference: Mod Path 1996;9:513

 

Melanoma

Adults, mean age 73

Usually involves distal urethra in men and women; less common in bladder

5 year survival ~ 20% (may die of unrelated causes), AJSP 2000;24:785

Treatment: total urethrectomy plus bilateral inguinal node dissection

Gross: polypoid, mean 2.6 cm

Micro: vertical growth phase often has prominent nodular component; also radial growth phase; abundant eosinophilic cylasm with large nuclei and prominent nucleoli; numerous mitoses; melanin pigment usually present, but often focal

DD: urothelial carcinoma, sarcomatoid carcinoma

 

Staging - urethral carcinoma

Should exclude metastastic disease

 

Primary tumor (T) (male and female)

TX: primary tumor cannot be assessed

T0: no evidence of primary tumor

Ta: noninvasive papillary, polypoid or verrucous carcinoma

Tis: carcinoma in situ

T1: tumor invades subepithelial connective tissue

T2: tumor invades corpus spongiosum, prostate or periurethral muscle

T3: tumor invades corpus cavernosum, beyond prostatic capsule, anterior vagina, bladder neck

T4: tumor invades other adjacent organs

 

Urothelial (transitional) carcinoma of prostate

Tis pu: carcinoma in situ, involvement of prostatic urethra

Tis pd: carcinoma in situ, involvement of prostatic ducts

T1: tumor invades subepithelial connective tissue

T2: tumor invades corpus spongiosum, prostatic stroma or periurethral muscle

T3: tumor invades corpus cavernosum, beyond prostatic capsule, bladder neck (extraprostatic extension)

T4: tumor invades other adjacent organs (invasion of bladder)

 

Regional lymph nodes (N)

NX: regional lymph nodes cannot be assessed

N0: no regional lymph node metastasis

N1: metastasis in a single lymph node, 2 cm or less in greatest dimension

N2: metastasis in a single lymph node more than 2 cm in greatest dimension, or in multiple nodes

 

Distant Metastasis (M)

MX: distant metastasis cannot be assessed

M0: no distant metastasis

M1: distant metastasis

 

Stage grouping

Stage 0a: T1a N0 M0

Stage 0: T1s N0 M0  or  Tis pu N0 M0  or  Tis pd N0 M0

Stage 1: T1 N0 M0

Stage 2: T2 N0 M0

Stage 3: T1-T2 N1 M0, T3 N0-N1 M0

Stage 4: T4 or N2 or M1

 

End of urethra outline