Pathology of the Male Reproductive System

Question 1

What is cryptorchidism? What typically causes this?

Answer 1

incomplete descent of the testis and associated structures into the scrotum
(canine testicular descent is typically at 3 months)

higher intra-abdominal temperature causes hypoplasia and degeneration/atrophy, which causes lack of spermatogenes

Question 2

Cryptorchid testicles are more likely to develop neoplasia. What neoplasias are common in dogs and stallions?

Answer 2

DOGS = Sertoli cell tumor, Seminoma

STALLIONS = Seminoma, Teratoma

Question 3

Bilateral cryptorchidism:

Answer 3

unilateral Sertoli cell tumor

Question 4

Sertoli cell tumor:

Answer 4

+ testicular torsion

Question 5

What is testicular hypoplasia?

Answer 5

testes that have failed to grow to normal size, detected right after puberty
- congenital/genetic
- UNILATERAL or bilateral

Question 6

What are the 2 most common causes of hypoplasia? What is the best known example?

Answer 6

1. cryptorchidism
2. endocrine disorder - reduced production of LH and FSH

Klinefelter’s syndrome (XXY) in tricolor male cats

Question 7

Testicular hypoplasia, yearling ram:

Answer 7

• testes and epididymis are very small compared with normal-aged controls
• seminiferous tubules are lined only by Sertoli cells and there is no spermatogenesis

Question 8

Tesitcular hypoplasia:

Answer 8

testicles/epididymis are small, but movable in the scrotum
- not apparent until after puberty

Question 9

What is testicular degeneration and atrophy? What is it the most common cause of?

Answer 9

testes that reduce in size AFTER puberty

infertility

Question 10

What 7 things is testicular degeneration/atrophy commonly secondary to?

Answer 10

1 epididymitis/scrotal diseases**
2. trauma
3. partial loss of blood flow
4. advancing age
5. chemotherapy
6. hormones
7. neoplasia

Question 11

How does testicular degeneration/atrophy present? What is important to note in young, growing males?

Answer 11

testes is small and firm (fibrosis) and may be attached to the scrotal wall; epididymis tends to be more normal in size or even enlarges

distinction between degeneration and hypoplasia if difficult - they often present together because hypoplastic testes are prone to degeneration

Question 12

Testicular degeneration/atrophy:

Answer 12

fibrosis!

Question 13

How is testicular hypoplasia and degeneration/atrophy typically differentiated?

Answer 13

HYPOPLASIA = testicle is small and freely movable in the scrotum, epididymis is also small and poorly developed; irreversible

ATROPHY: testicle is small, firm, and may be attached to the scrotal wall, epididymis tends to be normal; regeneration possible

Question 14

Why is true orchitis rare? What are the 4 portals of entry for orchitis?

Answer 14

usually associated with epididymitis

1. HEMATOGENOUS = Brucella aborus in bulls; C. pseudotuberculosis and B. ovis in rams; B. suis in boars; B canis and Blastomyces dermatitidis in dogs
2. DIRECT PENETRATION = bite wound, foreign body
3. ASCENDING INFECTION** = E. coli, Proteus, Staph/Strep, Histophilus, Actinobacillus seminis
4. PERITONEAL (periorchitis) - FIP in cats, peritonitis

Question 15

Orchitis, Brucellosis:

Answer 15

Question 16

When is it common in pigs for peritoneal spread to cause orchitis?

Answer 16

Glasser’s disease

Question 17

What are the 2 most common types of epididymal disorders?

Answer 17

DEVELOPMENTAL: aplasia/hypoplasia, spermatic granuloma

INFLAMMATORY: infectious, non-infectious (spermatic granuloma)

Question 18

In what species is segmental aplasia/hypoplasia in the epididymis most common? What 3 things does it typically lead to?

Answer 18

bulls —> involving the body and the tail (usually unilateral)

1. back pressure and secondary testicular degeneration
2. sperm impaction secondary to obstruction
3. dilatation (spermatocele) and/or rupture

Question 19

What is a spermatic granuloma? What are 3 causes?

Answer 19

epididymal rupture with extravasation of spermatozoae to the interstitium leading to a granulomatous response

1. congenital = epididymal head due to blind-ended efferent ductules
2. mechanical trauma = anywhere
3. secondary to epididymitis = anywhere

Question 20

Spermatic granuloma:

Answer 20

mass of spermatozoa in the interstitial CT of the epididymis is surrounded by macrophages and multinucleated giant cells

Question 21

What are the noninfectious causes of epididymitis? Infectious?

Answer 21

NONINFECTIOUS = trauma, congenital and acquired obstructions with secondary sperm granuloma

INFECTIOUS:
- ascending bacterial infection from genitourinary tract: Actinobacillus seminis, H. somni in rams, E. coli, Proteus
- hematogenous: Brucella spp., B. ovis and B canis most common

Question 22

Epididymitis, dog:

Answer 22

Question 23

Epididymitis, Brucella ovis:

Answer 23

Question 24

Necrotizing epididymitis and orchitis:

Answer 24

B. suis

Question 25

In what species are testicular tumors most common? What are the 3 most common?

Answer 25

+++ dogs, + stallions, rare in other species almost always benign - no indication of metastasis 1. Sertolic cell tumor 2. interstitial (Leydig) cell tumor 3. Seminoma, Teratoma (germ cells

Question 26

How do interstitial (Leydig) tumors typically present? What are commonly also seen?

Answer 26

tan to yellow-orange, well-demarcated, soft, and spherical - cysts - hemorrhage

Question 27

How do Sertoli cell tumors typically present? When are they most common?

Answer 27

firm (abundant stroma), white, and round to multilobulated cryptorchid canines

Question 28

What hormone do Sertoli cell tumors typically produce? What 4 things does this commonly cause?

Answer 28

estrogens 1. feminization - gynecomastia, penile and testicular atrophy, loss of libido 2. alopecia 3. bone marrow suppresion - anemia, leukopenia, thorombocytopenia 4. prostatic disease - squamous metaplasia

Question 29

Sertoli cell tumor presentation:

Answer 29

Question 30

Where are seminomas derived from? How do they typically present?

Answer 30

germinal cells of the testis (within the seminiferous tubules) bulges from cross-section, are white to gray, glistening, and soft ---> can be multicentric within the testicle

Question 31

How do seminomas compare to other testicular neoplasms?

Answer 31

tend to be more invasive and metastatic potential cannot be predicted

Question 32

Seminoma, stallion:

Answer 32

metastasis to splenic lymph nodes

Question 33

What are teratomas? In what species are they most common?

Answer 33

germ cell tumors that tend to be large, solid to cystic, and contain recognizable hair, bone, mucus, and teeth younger stallions in cryptorchid testicles - usually benign

Question 34

What is a varicocele? In what species are they most common? What does this commonly cause?

Answer 34

dilation of the spermatic veins in the pampiniform plexus older rams - thrombosis - affects thermoregulation and can lead to testicular degeneration

Question 35

Varicocele:

Answer 35

- larger than testis - multinodular from large thromboses filling the dilated veins

Question 36

When is torsion of the spermatic cord common?

Answer 36

- cryptorchid testicles - testicles with neoplasms

Question 37

When is inflammation of the spermatic cord (funisitis) most common?

Answer 37

following contamination of castration wounds

Question 38

In what animals is vesicular adenitis most common? How is it diagnosed?

Answer 38

bulls rectal palpation

Question 39

What is the main form of vesicular adenitis? What are the most common infectious causes?

Answer 39

chronic interstitial form - markedly enlarged and firm Brucella, Staph/Strep, Mycoplasma, T. pyogenes

Question 40

In which animals is prostatitis most common? What is it associated with?

Answer 40

older, intact dogs prostatic hyperplasia or squamous metaplasia (Sertoli cell tumor)

Question 41

What are the 2 most common causes of prostatitis?

Answer 41

1. ascending infection from the urinary tract epithelium - Proteus, E. coli, Staph/Strep 2. hematogenous - Brucella canis

Question 42

How does prostatitis afftect the animal?

Answer 42

- can compress ureters, leading to LUTI and pyelonephritis - can compress the colon and cause constipation

Question 43

Prostate hyperplasia:

Answer 43

Question 44

Prostatitis:

Answer 44

Question 45

Prostatitis + urinary bladder:

Answer 45

Question 46

Prostatitis, colon compression:

Answer 46

Question 47

From what 2 places do prostatic neoplasias typically arise from? In what animals is this most common?

Answer 47

1. prostatic epithelium (ducts and acini) 2. urethral epithelium (urothelial) dogs > 10 years old

Question 48

What are the 2 important features of prostatic neoplasia?

Answer 48

1. frequently metastasizes, especially to bone 2. causes asymmetrical enlargement

Question 49

Prostatic carcinoma:

Answer 49

asymmetrical enlargement of affected kidney

Question 50

Prostatic carcinoma:

Answer 50

- assymetric enlargement - focal white areas are regions of necrosis - gland is enlarged due to neoplastic epithelial cells

Question 51

What is the difference between balanitis, posthitis, and balanoposthitis?

Answer 51

BALANITIS = inflammation of the head (glans) of the penis POSTHITIS = inflammation of the prepuce BALANOPOSTHITIS = inflammation of the glans and the prepuce

Question 52

What 3 diseases most commonly affect the penis?

Answer 52

1. equine coital exanthema - equine herpesvirus-3 2. infectious balanoposthitis - bovine herpesvirus-1 3. ulcerative posthitis in castrated rams - Corynebacterium renale

Question 53

Ulcerative balanoposthitis:

Answer 53

equine coital exanthema - equine herpesvirus-3

Question 54

Bovine infectious balanoposthitis:

Answer 54

bovine herpesvirus-1

Question 55

What are 2 major causes of ulcerative posthitis in castrated rams?

Answer 55

1. castration leads to these animals urinating within their prepuce 2. diets rich in protein have high concentrations of urea, allowing Corynebacterium renale to break it down into ammonia, which is cytotoxic

Question 56

What tends to cause granulomatous balanoposthitis in horses?

Answer 56

Habronemiasis

Question 57

What 3 neoplasias are most common in the penis and prepuce?

Answer 57

1. penile squamous cell carcinoma in horses 2. fibropapilloma of bulls 3. canine TVT

Question 58

Where does penile squamous cell carcinoma arise? What previous infection can also cause it to arise?

Answer 58

sheath of the penis of older horses (stallions = geldings) papillomas caused by Equus caballus papillomavirus type 2 (EcPV2)

Question 59

How do penile squamous cell carcinomas present?

Answer 59

medium to large tumors with areas of ulceration

Question 60

Penile squamous cell carcinoma:

Answer 60

Question 61

At what age are fibropapillomas most common in bulls? What causes it? How does it typically present?

Answer 61

young bulls, 1-2 years bovine papillomavirus 1 and 2 exophitic mass that typically spontaneously regresses

Question 62

Fibropapilloma of bulls:

Answer 62

Question 63

How does canine TVT typically present? How are they aquired?

Answer 63

arises on the penis or within the prepuce and can be single, multiple, nodular, or papillary ---> solid sheets of uniform round, ovoid, or polyhedral cells with large round vesicular nuclei transplants from one dog to another at intercourse (allograft)

Question 64

How does canine TVT typically progress? What does it involve when it metastasizes?

Answer 64

spontaneous regression can occur and most are sensitive to chemotherapy with vincristine involves the superficial inguinal lymph nodes, skin (from trauma and mechanical implantation), and other organs