Male Genitourinary

Male Genitourinary

Prostate

Anatomy

·        Normally 20 – 30 g.  Grossly enlarged can be 500g

·        Prostate can become infected, hyperplastic or malignant

·        Used to be described in lobes.  Now described in zones:

o   Anterior zone

o   Transition and central zone: main site of benign hyperplasia

o   Peripheral zone: main site of malignancy.  Next to rectum – can palpate on PR

·        PR exam: 

o   Even if normal, don‟t ignore ­PSA. Cancers can be small or diffuse, or anterior, in an already large prostate ® PR isn‟t sensitive 

o   Nodularity can be detected on PR. This is due to desmoplasia (fibrous reaction) – usually to a slower infiltrating cancer

Prostatitis

·        Acute:

o   Gonorrhoea most common cause: pain, discharge, haematuria, tender on PR

o   May be infarction secondary to hyperplasia compressing blood supply

·        Granulomatous:

o   Tb (rare)

o   Fungal (only immunocompromised)

o   Leakage of prostatic secretion into interstitium post surgery 

o   Resolving prostates (hard, knobbly prostate, ­PSA, mistaken for malignancy). Suspect post surgery, but still need biopsy

Benign Prostatic Nodular Hyperplasia

·        Not benign if not treated: ® hydronephros ® kidney failure ® death!

·        Common: 75% of all men over 75 years of age 

·        Testosterone ¯ with age ® ­oestrogen ® potentiates effect of Dihydrotestosterone (DHT) on the prostate ® prostatic hyperplasia 

·        Morphology: nodular proliferation of ducts, mainly in the central zone

·        Histology: epithelial nodules, fibrosis, chronic inflammation, focal infarction

·        Management:

o   Transurethral prostatic resection (TURP): always ® retrograde ejaculation + risk of impotence and incontinence

·        5 a Reductase Inhibitors (blocks Testosterone ® DHT). Usually preferred. OK if not acute obstruction

Prostatic Carcinoma

·        Occurs in 25% of males over 70 years.  (More if include indolent central or transition zone tumours)

·        6% mortality in males

·        Predominantly adenocarcinoma occurring in the peripheral zone 

·        Key histological features: single cell basal layer in duct epithelium, prominent nucleolus, lots of small glands

·        Prognosis related to Grade (using Gleason score: 2 is good, 10 is very bad)

·        Spreads to pelvic lymph nodes via perineural infiltration

·        Prostate Specific Antigen: 

o  PSA – a tumour marker. Screening test only. ­Serum PSA correlates with tumour burden. PSA is a lytic agent that makes seminal fluid runny. If > 4 then do free to bound ratio, and/or follow/refer patient 

o  ­In benign and malignant tumours, or inflammation

·        Management:

o  Transurethral resection

o  Radiotherapy 

o  Radical prostatectomy (selected on basis of tumour bulk and grade (not if very high grade – will already have metastasised). 50% have complications (impotence, incontinence)

 Workup of Obstruction from Enlarged Prostate

·        Investigations:

o  Cr: checking renal function

o  K and Na: checking renal failure

o  Blood gases for metabolic acidosis

o  PSA

o  Ultrasound: look for distended bladder and hydronephrosis

o  ECG if ­K: if ECG changes or if K high then may need anti-arrhythmic

·        Management:

o  Catheterise: should see K and Cr resolve over a day (depending on remaining renal function)

o  If high K, then insulin + glucose

·        Complications of obstruction: 

o  Enlarged bladder: hyperplasia of detrussor muscle fibres, ­space between trabeculated fibres

o  ­Back pressure in ureter ® hydronephrosis

§  ¯Filtration ® ­Cr

§  ¯Function of tubular epithelium due to poor perfusion ® ¯active transport of K

§  Acidosis

·        Moral: Must act on a distended bladder to protect the kidney

Prostate Cancer Screening*

·        Notes prepared for Public Health Test. Does PSA meet the 6 criteria for a good screening test? Source: Readings on Closed Reserve

·        Is it an important health issue:

o  2^nd leading cause of cancer death in men in the US.  In NZ, 800 cases and 400 deaths per year

o  A disease of the very old. 1% < 55 years, 65% > 75 years. Would reducing incidence lead to decline in all-causes mortality?

·        Is there a suitable test: PSA test + digital rectal exam. PSA test is reasonably good at detecting pathology, and sensitivity is improving (currently ~ 80%)

·        Is the natural history well understood:

o  Wide variety of cancers: from the slow growing, indolent sort to very aggressive

o  Need long enough asymptomatic duration to allow screening at reasonable intervals

o  Screening likely to detect indolent cancers (length bias) 

o  Incidence of prostate cancer has increased dramatically since opportunistic screening introduced ® treating many cancers that would have remained harmless (ie would die WITH cancer but not BECAUSE of cancer)

·        Does treatment at the asymptomatic stage confer positive benefits over later treatment:

o   No firm evidence that radical prostatectomy is better than conservative treatment for asymptomatic cancers

o   For Grade I and II cancers, evidence that conservative treatment is at least reasonably effective

o   Risks of prostatectomy: 30-day mortality of 0.5% + significant levels of ongoing incontinence and sexual dysfunction

o   Assuming 4% rate of detection from screening, 1 in 5000 will die, 1 in 81 will be incontinent, and 1 in 36 will have sexual dysfunction as the result of the screening

o   Conclusion: Screening is good at detection pathology, but don‟t yet know if treatment is beneficial in net terms

·        Infrastructure and cost: of lesser relevance until it can be demonstrated that screening is clinically effective

Penis

·        For congential malformations and paediatric presentations

·        Epispadias: abnormal opening of urethra on ventral surface

·        Fractured Penis: Rupture of corpus cavernosum during erection

·        Condyloma: Genital wart. Usually flat.  Associated with HPV. 

·        Erythroplasia of Queyrat (= Bowen‟s disease): non-invasive cancer of the penis. Premalignant condition. Usually starts in coronal sulcus. 

·        Squamous cell carcinoma: Very rare, ­ risk if not circumcised. Early spread to lymph nodes but doesn‟t disseminate widely

Scrotum

·        Steatocystoma: benign sebaceous cysts, hereditary

·        Fournier‟s gangrene: Ischaemic necrosis.  Little collateral flow to the scrotum so occlusion ® domino

·        effect.  Treatment: debridement

·        Squamous cell carcinoma

Testes

·        For Torsion and Hydrocoele, see Testes (Topic)

Infection

·        Epididymo-orchitis:

o   Bacterial infection: E Coli, Klebsiella, Proteus

o   In adults also Gonorrhoea 

o   Usually self-limiting ® antibiotics

o   Key differential: torsion.  If in doubt, emergency referral and Doppler US to assess blood flow

·        Primary Orchitis:

o   Mumps, Tb, tertiary syphilis

o   Rare

Other

·        Spermatocoele: dilation of a chord of epididymis: common benign small lump on testis. Translucent to torch

·        Haematocoele: Haemorrhage into tunica vaginalis or tunica albicinia (rugby injury, bleeding disorder)

Testicular Tumours

·        Incidence 3.5/100,000

·        3% bilateral

·        7% associated with undescended testis

·        Germ cell tumours:

o   95% of testicular tumours

o   Derived from germ cells

o   Peak in 15 – 34 year olds

o   Painless swelling of the testis

o   Seminoma:

§  40% of testicular tumours

§  Gross: lobulated pale tumour mass 

§  Micro: Undifferentiated germ cells + ­ lymphocytes. Aggressive. Metastasise to inguinal and para-aortic nodes 

§  Treatment: Orchidectomy via inguinal region (never via scrotum ® different lymphatic drainage. Also never biopsy suspected testicular cancers). Very responsive to radiotherapy

o  Teratoma:

§  30% of testicular tumours

§  All can recapitulate ectodermal, mesodermal and endodermal tissue

§  Benign teratoma: More common in ovary than testis. 3% chance of malignant change. Mature tissues (usually skin elements – epidermis, hair follicles, etc)

§  Malignant teratoma: metastasise to para-aortic lymph nodes (especially neural cells – very

§  aggressive). Gross appearance – lots of variety. Treatment: chemo +/- radiotherapy. Chemo stimulates cells to mature ® still malignant but slower growing ® excision of affected lymph nodes

o  Embryonal carcinoma: poorly differentiated, resembles adenocarcinoma. Highly malignant. May express tumour marker alpha-fetoprotein

o  Choriocarcinoma: Placental tissues (resembles hydatiform mole). Expresses bHCG ® positive for pregnancy test. Contains highly malignant syncytiotrophoblast and cytotrophoblast cells. Responds well to chemotherapy

o  Mixed tumours: Teratoma and seminoma

·        Sex chord/stromal tumours:

o  Leydig tumours: 90% benign. Small brown mass. Present with overproduction of testosterone: precocious puberty or gynaecomastia in post-puberty. Can produce androgens, oestrogen or corticosteroids 

o  Sertoli cell tumours: Rare. 90% benign. Within seminephrous tubules of the testis. Local infiltration

·        Lymphoma: Older males, often bilateral, poorly differentiated and poor prognosis

·        Testicular tumours present relatively young, lymphoma in older men

Differential of Testicular Swelling