Prostate Physiology and Disease Flashcards
What is the anatomy of the prostate?
- Largest reproductive male organ
- Retroperitoneal organ, encircling the neck of the bladder and urtehra
- Prostate weighs 20 grams in normal adult
- Devoid of a distinct caosule
- Four distinct zones:
- Central zone
- Peripheral zone ( place for most carcinomas)
- Transitional zone ( Place for hyperplasia)
- A periurethral zone
What is the prostate histology?
- Histologically the prostsate is composed of glands lined by 2 layers of cells
- A basal layer of low cuboidal epithelium covered by a layer of columnar secretory cells
- Small papillary infolding of the epithelium in many areas
- These glands are separated by abundant fibromuscular stroma
- Testicular androgens - control the growth and survival of prostatic cells
What is the function of the prostate?
- Accessory sex gland
- to secrete prostate fluid
- contents include : PSA, Prostaglandins, Fructose, Zinc, Citrate
- The muscles of the prostate gland also help propel this seminal fluid into the urethra during ejaculation
- PSA : Liquefying semen that has thickened after ejaculation. This allows sperm to swim more freely.
What are some prostate pathologies?
- Prostatitis
- Benign prostatic hyperplasia (BPH)
- Prostate cancer
What is prostatitis?
- Acute (supparative prostatitis)
- E coli, rarely staph or Neissera gonorrhoeae
- Chronic : non-specidic or diagnosed by increased leucocytes in prostatic secretions but no bacteria found:
- Chronic bacterial prostatitis
- Granulomatous : e.g. disseminated TB, allergic (eosinophilic)
- Symptoms :
- Dysuria, frequency, lower back pain, pelvic pain
- DRE ( Digital rectal examination) :enlarged tender prostate
What is Benign Prostatic Hyperplasia (BPH) ?
- Proliferation of both stromal and epithelial elements (glands)
- Incidence:
- Old age : 20% in men over age 40, up to 70% by age 60 , and 90% by age 70
- Ethnicity : Common in black> White> Asian
- Related to the action of androgen
What is DHT?
- Dihydrotestesterone = the ultimate mediator for prostatic grotwth
- Formed in the prostate from the conversion of testosterone by the enzyme tyoe 2 5 alpha reductase ; located almost entirely in stromal cells
- Epithelial cells of the prostate do not contain type 2 5 a reductase
- Type 1 5a- reductase- not detected in the prostate. Howeveer, this ennzyme may produce DHT from testosterone in liver and skin
- Circulating DHT may act inm the prostate by an endocrine mechanism
What is the morphology of BPH?
- Large - 60-100g
- Enlargement occurs almost in the Transitional zone (TZ)
- Histologic feature of BPH is glandular and stromal proliferation
- Digital rectal examination shows smooth, firm, enlarged prostate with no nodules
- The increased size of the gland, and the smooth muscle-mediated contraction of the prostate cause urethral obstruction
What are the clinical presentations of BPH?
- Lower Urinary Tract Symptoms :
1. Voiding symptoms (Obstructive) : weak or intermittent ironary flow, straining, hesistancy, terminal dribbling and incomplete emptying
2. Storage symptoms (Irritative) : urgency, frequency, incontinence and nocturia
3. Complications : Urinary tract infection, retention, obstructive uropathy
HIFUN:
- Hesitancy
-** I**ntermittent, incontinence
- Frequency, fullness
- Urgency
- Nocturia
What are BPH complications?
- Obstructive uropathy (catheter)
- Bladder hypertrophy
- Trabeculation
- Diverticula formation
- Hydroureter - bilateral
- Hydronephrosus
- Lithiasis/ stone
- Secondary infection
Not a risk factor for carcinoma prostate
What is the management of BPH?
MANAGEMENT
* Life-style: symptomatic treatment.
Medical treatment:
1) alpha 1-antagonists e.g Tamsulosin
which decrease prostate smooth m scl tone
(prostate and bladder neck).
Adverse effects: dizziness, postural hypotension
and dry mouth.
2) 5-a-reductase inhibitors e.g Finasteride
- block the conversion of testosterone to DHT
- causes reduction in prostate volume.
- takes about 6 months to improve the conditio
- Adverse effects: erectile dysfunction, reduced libido,
ejaculation problems and gynaecomastia.
Surgical: Transurethral resection of the prostate (TURP)
* Partial removal by resectoscope
* Complications:
Intravesical view
Lateral lobe encirclement
1) Haemorrhage, Infection, Granulomatous
prostatitis and Retrograde ejaculation.
2) TURP syndrome:
- excessive irrigation used during the
operation for better visualisation»_space;
irrigation fluid enters the systemic
circulation through the prostatic veins»
Hyponatremia (less Na).
- Clinical picture: confusion, bradycardia,
nausea and vomiting.
- treatment: fluid restriction.
What is Prostate cancer?
- A disease of men over age 50
- Most common cancer in male in the UK
- Common in black ppl
- Risk factors :
- Age
- Family history (1st degree relative)
- High dietary fat and Obesity
- Vit D or E deficiency
What is the pathology of prostate cancer?
- most common form = adenocarcinoma (Glandular prostate cancer). Forms in the glandular epithelial cells that line the insides of organs and secrete mucus, digestive juices or other fluids
Microscopic Examination :
- Prostate glands are typically smaller than benign glands
- Lined by a single uniform layer of cuboidal or low columnar epithelium
- Outer basal layer typical of benign glands is absent
How is Prostate Cancer graded and what is the staginf?
- Gleason score/ using the gleason pattern scale
- Grade cancer 1-5
- Prognosis related to stage and grade
- 1 = well differentiated cells . 5 - lack of or occasional glands, sheets of cells
What is the presentation of prostate cancer?
- Early stages usually asymptomatic:
- Most cases detected by serum PSA screening
- Palpable nodule or firmness on DRE
Advanced stages: - Urinary retention/ renal failure
- Bone pain
- Anaemia
- Weight loss, fatigue
- Spinal cord compression
