Chapter 113: 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 - higher ratios almost always mean changes are there
• Scottish Terriers

Question 2

Is the prostate peritoneal or retroperitoneal?

How does it move around with age?

Answer 2

Both! Its ventral aspect is retroperitoneal
It starts out abdominal -> urachal vestige breaks down at 2mo and it moves pelvic -> puberty starts an abdominal movement / half abdominal by 4 yr and moves to be fully abdominal by 10 yr of age

Question 3

What nervous input increases glandular secretion?

Answer 3

Parasympathetic supply from the pelvic nerve

Question 4

What are the 2 forms of acinar dilation are seen within the mature prostate? When do signs of activity appear?

Answer 4

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

Start around 4 months of age

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 relaeased from the prostate gland during ejaculation?

Answer 6

Large amounts of prostaglandin E2

Question 7

What substances are found within prostatic secretion? What is it’s pH?

Answer 7

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

pH 6.1-6.5

Question 8

List anatomical differences of the feline prostate

Answer 8

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

Question 9

What is Glandular BPH?

Answer 9

○ More common in young dogs (<4-5 years)
○ Changes occur in primarily secretory cells which increase in number and size, resulting in symmetric enlargement
■ Only minor changes to supporting smooth muscle and stromal tissue
■ Histologic structure remains organized
○ Mediated by dihydrotestosterone
■ Circulating testosterone metabolized to 5alpha-dihydrotestosterone → regulates gene expression in nuclei to control prostatic growth
○ As prostate increases in size → tissue dihydrotestosterone concentration decreases → onset of complex hyperplasia

Question 10

What is complex hyperplasia for BPH?

Answer 10

○ More common form in older dogs > 5 years
○ Changes are characterized by an asymmetric enlargement that contains both glandular and prominent stromal elements
■ Within stroma, areas of atrophy are common
■ Alveoli show cystic changes with eosinophilic material and inflammatory cells (lymphocytes, plasma cells)
■ Ultrastructural changes = prominent microvilli, crowding with papillary projections, abundant granules, and caveolae in basal cells
○ Mediated by increased numbers of receptors and responsiveness to dihydrotestosterone, NOT due to higher concentrations of dihydrotestosterone
○ Mitotic figures are found with same frequency in prostate affected by BPH as in the normal gland, suggesting that increased size is maintained not through increase in cell proliferation but through a decrease in cell death