Prostate

Question 1

What is the normal size of the prostate?
What breed can have a healthy larger prostate?

Answer 1

• 0.64-0.96g/kg
• Scottish Terriers

Question 2

Is the prostate peritoneal or retroperitoneal?

Answer 2

Both! Its ventral aspect is retroperitoneal

Question 3

What nervous input increases glandular secretion?

Answer 3

Parasympathetic suppy from the pelvic nerve

Question 4

What are the 2 forms of acinar dilation seen within the mature prostate?

Answer 4

• Simple dilatation: Many dilated acini with or without luminal oesionphilic secretions which no not compress adjacent acini
• Focal glandular ectasia: Focal dilatation of a few acini with oesinophilic content and compression of the adjacent prostatic parenchyma

Question 5

List the functions of the prostatic secretions

Answer 5

• Promote spermatozoa motility and viability
• Increase uterine perfusion
• Modulate neutrophil-induced inhibition of spermatazoa attachment to uterine epithelium

Question 6

What hormone is relaease from the prostate gland during ejaculation?

Answer 6

Large amounts of PGE2

Question 7

What substances are found within prostatic secretion?

Answer 7

• High concentration of zinc and zinc-binding proteins
• Acid phosphatase (also produced by epididymis)
• Canine prostate-specific esterase (90% total protein)

Question 8

What is glandular BPH?

Answer 8

• predominates in younger dogs
• Secretory cells increase in number and size leadng to symmetric enlargement
• Testosterone is metabolised by 5alpha-reductase in the prostate to 5alpha-dihydrotestosterone
• Regulates gene expression in the nuclei to control prostatic growth

Question 9

What is complex BPH?

Answer 9

• Most common form, predominates in older dogs
• As the prostate increases in size, 5alpha-dihydrotestosterone concentrations decrease
• Paralleled by increase in metabolism of androgens within the prostate and increasing numbers of nuclear androgen receptors (increases responsiveness to androgens and decrease in apoptosis)
• Asymmetric enlargement, envolving both glandular and prominent stromal elements

Question 10

How is oestrogen throught to play a role in BPH?

Answer 10

• Increases the sensitivity of the prostate to dihydrotestosterone bu inducing nuclear dihydrotestosterone receptors and promoting stromal and collagen synthesis
• May also exert inhibitory role on cell death

Question 11

Which form of prostatic disease may not cause enlargement?

Answer 11

Neoplasia

Question 12

What is regarded as the primary imaging tool of the prostate?

Answer 12

Ultrasound

Question 13

What are the Tx options for BPH?

Answer 13

• Castration - resolution within a few days

Medical:
- Antiandrogens - delmainone acetate. Progestogen with antiandrogenic and antioestrogenic activity by suppressing interstitial cell function. Flutamide binds to dihydrotestosterone receptors
- LH Inhibitors - Megestrol acetate, medroxyprogesteronei - progesterone derivatives that inhibit LH release and suppress 5alpha-reductase. May induce squamous metaplasia
- GnRH agonists/analogues - block pituitary receptor sites, causing reduction in natural LH-RH and decline in testicular secretion of testosterone. Can be given as long acting injection or implant
- 5alpha-reductase inhibitor - Finasteride
- Oestrogens - Can cause BM aplasia and prostatic metaplasia…

Question 14

List the natural defense mechanism against bacterial prostatitis

Answer 14

• SHedding or uropathogens bound to exfoliating urethral cells
• bacterial trapping by secreted mucous
• Intermittent washout by urine
• Local immunoglobulins, cytokines and defensins
• Mobilisation of leucocytes

Question 15

What is the most common bacterial cause of prostatitis?

Answer 15

E.Coli

Question 16

What is the pathognomonic appearance of prostatic abscesses on ultrasound?

Answer 16

Multiloculated appearance of capsular tissue surrounding material with a flocculent fluid signal

Question 17

List the surgical options for prostatic abscessation

Answer 17

• Castration and ABx
• marsupialisation (rarely done)
• Active or passive drainage (20% mortailty)
• Omentalisation (consistently sucessful, low complications)
• Partial prostatectomy (risk of incontinence and severe haemorrhage)

Question 18

What ABx have good penetration of the blood-lipid barrier of the prostate?

Answer 18

• Enrofloxacin
• Marbofloxacin
• TMS
• Chloramphenicol

Barrier is likely less functional in the inflamed prostate so this is of unclear significance

Question 19

What are the surgical options for prostatic cysts?

Answer 19

• Complete resection if small and minimally attached
• Partial resection and omentalisation

Question 20

What is the most common form of prostatic neoplasia?

Answer 20

Adenocarcinoma

Androgen receptor negative - castration is not an effective Tx

Question 21

What gene has been associated with an increased risk of prostatic carcinoma?

Answer 21

short CAG-1 repeats in the andorgen receptor gene

Question 22

How can prostatic carcinomas be subclassified?

Answer 22

Differentiation
- glandular
- urothelial
- squamoid
- sarcomatoid

Growth patterns:
- papillary
- cribiform
- solid
- small acinar/ductal
- signet ring
- mucinous

Consistent aggressive with high met rate 80% and 20% mets to axial skeleton

Question 23

What % of prostatic carcinoma cells express COX-2?

Answer 23

75%

Question 24

What are the Tx options for a prostatic carcinoma?

Answer 24

• Tube cystotomy or urethral stenting for palliation
• NSAIDs - improve survival
• Partial or complete prostatectomy
• Radiation
• Nd:YAG partial prostatectomy

Question 25

What causes prostatic metaplasia?

Answer 25

Abnormally increased circulating oestrogens - Sertoli cell tumour - seminoma - exogenous

Question 26

What is the main complication with total prostatectomy?

Answer 26

- Likely urinary incontinence - Possibility of significant haemorrhage - required temporary aortic occlusion

Question 27

List anatomical differences of the feline prostate

Answer 27

- Only partially encircles the urethra (dorsolaterally) - Can have some prostatic tissue disseminated within the urethral wall caudal to the prostate