Ch 113 - Prostate Flashcards
What is the normal size of the prostate?
What breed can have a healthy larger prostate?
- 0.64-0.96g/kg
- Scottish Terriers
Is the prostate peritoneal or retroperitoneal?
Both! Its ventral aspect is retroperitoneal
What nervous input increases glandular secretion?
Parasympathetic suppy from the pelvic nerve
What are the 2 forms of acinar dilation seen within the mature prostate?
- 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
List the functions of the prostatic secretions
- Promote spermatozoa motility and viability
- Increase uterine perfusion
- Modulate neutrophil-induced inhibition of spermatazoa attachment to uterine epithelium
What hormone is relaease from the prostate gland during ejaculation?
Large amounts of PGE2
What substances are found within prostatic secretion?
- High concentration of zinc and zinc-binding proteins
- Acid phosphatase (also produced by epididymis)
- Canine prostate-specific esterase (90% total protein)
What is glandular BPH?
- 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
What is complex BPH?
- 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
How is oestrogen throught to play a role in BPH?
- 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
Which form of prostatic disease may not cause enlargement?
Neoplasia
What is regarded as the primary imaging tool of the prostate?
Ultrasound
What are the Tx options for BPH?
- 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…
List the natural defense mechanism against bacterial prostatitis
- 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
What is the most common bacterial cause of prostatitis?
E.Coli
What is the pathognomonic appearance of prostatic abscesses on ultrasound?
Multiloculated appearance of capsular tissue surrounding material with a flocculent fluid signal
List the surgical options for prostatic abscessation
- 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)
What ABx have good penetration of the blood-lipid barrier of the prostate?
- Enrofloxacin
- Marbofloxacin
- TMS
- Chloramphenicol
Barrier is likely less functional in the inflamed prostate so this is of unclear significance
What are the surgical options for prostatic cysts?
- Complete resection if small and minimally attached
- Partial resection and omentalisation
What is the most common form of prostatic neoplasia?
Adenocarcinoma
Androgen receptor negative - castration is not an effective Tx
What gene has been associated with an increased risk of prostatic carcinoma?
short CAG-1 repeats in the andorgen receptor gene
How can prostatic carcinomas be subclassified?
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
What % of prostatic carcinoma cells express COX-2?
75%
What are the Tx options for a prostatic carcinoma?
- Tube cystotomy or urethral stenting for palliation
- NSAIDs - improve survival
- Partial or complete prostatectomy
- Radiation
- Nd:YAG partial prostatectomy
What causes prostatic metaplasia?
Abnormally increased circulating oestrogens
- Sertoli cell tumour
- seminoma
- exogenous
What is the main complication with total prostatectomy?
- Likely urinary incontinence
- Possibility of significant haemorrhage - required temporary aortic occlusion
List anatomical differences of the feline prostate
- Only partially encircles the urethra (dorsolaterally)
- Can have some prostatic tissue disseminated within the urethral wall caudal to the prostate
