Thug’s
PATHOLOGY OF PROSTATIC ENLARGEMENT NORMAL PROSTATE
The prostate is a retroperitoneal organ encircling the neck of the bladder and urethra and is devoid of distinct capsule.
It consists of 1. two lateral
lobes 2. a median lobe
3. one anterior & one posterior lobe encircles prostatic urethra
In normal adults; prostate weighs about 20 gm
Histologically, the prostate is a compound tubuloalveolar gland with a stroma composed of smooth muscle.
Anatomically, the prostate is closely related to the rectum, and rectal examination permits digital palpation of its posterior aspect.
Common manifestation of prostatic diseases are: Obstruction of urinary flow/ Perineal pain/ Hematuria
3 DISTINCT ZONES OF PROSTATE
CENTRAL ZONE PERIPHERAL ZONE TRANSITION ZONE
Occupies 25% of the gland’s volume. This zone consist of mucosal glands which open directly into the urethra
70% & also the major site of prostatic cacer. The glands of this zone open into the urethra via long ducts.
Which is of the medical importance bcs it is the site where most benign prostatic hyperplasia originates. Glands of this zone are sumucosal, & they open into urethra via short ducts.
1. INFLAMMATION ACUTE PROSTATITIS CHRONIC PROSTATITIS
Acute suppurative inflammation
usually following cystitis or uretheritis caused by E.coli, staphylococci or gonococci.
Chronic non-specific: due to recurrent acute attacks
Chronic specific (granulomatous): post TURP, idiopathic, TB, allergic
Prostatic diseases are classified into
I- Inflammation
II-Prostatic hyperplasia
III- Neoplasms
Thug’s
2. PROSTATIC HYPERPLASIA GENERAL FEATURES TERMINOLOGY
Benign nodular enlargement or benign prostatic hypertrophy (BPH) is extremely common disorder in men over age 50 (>50%) & above 70 years (95%).
When sufficiently large, the nodules compress and narrow the urethral canal cause partial or sometimes virtually complete obstruction of the urethra
It is not a premalignant lesion
1. Prostatic enlargement: benign or malignant (a sign)
2. Prostatic hyperplasia: histological term 3. Prostatic obstruction: a clinical diagnosis 4. Bladder outlet obstruction: a urodynamic
term 5. Lower urinary tract symptoms: symptom
ETIOPATHOGENESIS
Considered to be related to the action of androgens, especially Dihydrotestosterone (DHT); a metabolite of testosterone, and the ultimate mediator of prostatic enlargement.
DHT is senthesized mainly in the stromal cells of the prostate
once it is formed it has autocrine and paracrine effect on the stromal cells and nearby epithelial cells.
DHT bind to nuclear androgen receptor and signal the transcription of growth factors
DHT is ten times more potent than androgens in combining to the androgen receptor and dissociate more slowly.
In old men with increase the estradiol level; estrogen induce an increase in androgen receptors thus making the cells more liable to DHT.
May be other factors may be involved due to heterogeniety of the disease
MORPHOLOGY
NAKED EYE MICROSCOPIC EYE
Overall, the gland is enlarged.
The periurethral part of the gland is most commonly involved.
May reaching massive size.
Firm, rubbery in consistency.
Small nodules are present throughout the gland, usually 0.5–1 cm in diameter but sometimes much larger.
Some of the larger nodules show cystic change
The glands are 1. composed of a variable mixture of hyperplastic
glandular elements & hyperplastic stromal muscle 2. are larger than normal 3. variable in size and shape 4. lined by tall epithelium that is frequently thrown
into papillary projections
The acini may contain numerous corpora amylacea.
Thug’s
CLINICAL FEATURES COMPLICATIONS Mainly obstructive symptoms due to: 1. The hyperplastic nodules
compress and elongate the prostatic urethra, distorting its course.
2. Involvement of the peri-urethral zone at the internal urethral meatus interferes with the sphincter mechanism
I. Continued obstruction of the bladder :
Outflow results in gradual hypertrophy of the bladder musculature.
Trabeculation of the bladder wall develops due to prominent bands of thickened smooth muscle between which diverticula may protrude.
II. Dilatation of the bladder occurs when the compensatory mechanism fails, this results: 1. The ureters gradually dilate hydroureter,
allowing reflux of urine 2. If untreated, bilateral hydronephrosis
may develop, with dilatation of renal pelvis and calyces
3. Repeated infections predispose to the development of calculi often containing phosphates, within the bladder.
4. Urinary incontinence
3. PROSTATIC CARCINOMA GENERAL FEATURES
Age - The tumor is rare below 50 The peak incidence is between 60 and 85 years
Incidence : 241,740 (29%)
Deaths : 28,170 (9%)
Thug’s
RISK FACTORS PROSTATIC INTRAEPITHELIAL NEOPLASIA (PIN)
1. Endocrinologic factors – Androgens (Orchiectomy reduce the tumor size in Prostatic carcinoma patient).
2. Racial factors- More common in African 3. Environmental factors- high fat diet, exposure to
polycyclic aromatic hydrocarbons 4. Genetic basis- familial cases (Chromosome No 1 & 10)
PIN is a precursor lesion suggests that Prostatic carcinoma may also be present.
Consists of intra-acinar proliferation of cells that demonstrate nuclear anaplasia found in a single acinus or small group of prostatic acini
GROSS APPEARANCE MICROSCOPIC Peripheral zone in the posterior lobe of the gland
Palpable in rectal exam
Multifocal, gritty and firm
Back to back arrangement of the malignant glands, lining cells show prominent nucleoli.
Invasion of stroma and perineural spaces
PRESENTING FEATURES SPREAD 1. Clinically silent & Latent carcinoma: unexpected finding in autopsy 2. Incidental carcinoma: in 15-20% of TURP done for BPH. 3. Clinical carcinoma: detected by PR, other investigations & is symptomatic. 4. Occult carcinoma: presents with features of metastases but primary is not evident.
1. Local spread: Tends to invade nerves, seminal vesicles & adjacent pelvic organs (local extension) 2. Lymphatic spread: To para-aortic, iliac LN 3. Hematogenous metastases:
most often found in the vertebrae & sacrum;
can also occur in kidneys, lungs & brain 4. Bony metastases are often osteoblastic & are associated with elevated serum alkaline phosphatase
DIAGNOSIS 1. Digital rectal examination 2. Diagnostic imaging -ultrasound, skeletal X-rays,
isotope bone scan (osteoblastic bone metastasis).
3. Cystoscopy -including transurethral resection
4. Chemical pathology –serum prostate-specific antigen (PSA>10ng/ml), Prostatic acid phosphatase (PAP), and alkaline phosphatase
5. Biopsy -transurethral resection, needle biopsy, fine-needle aspiration cytology.
GRADING STAGING
G :Gleason grades
(Score): based on the
degree of
differentiation among
the cells
S: TNM Staging