Pathology of the Male Reproductive System Flashcards
What is cryptorchidism? What typically causes this?
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
Cryptorchid testicles are more likely to develop neoplasia. What neoplasias are common in dogs and stallions?
DOGS = Sertoli cell tumor, Seminoma
STALLIONS = Seminoma, Teratoma
Bilateral cryptorchidism:
unilateral Sertoli cell tumor
Sertoli cell tumor:
+ testicular torsion
What is testicular hypoplasia?
testes that have failed to grow to normal size, detected right after puberty
- congenital/genetic
- UNILATERAL or bilateral
What are the 2 most common causes of hypoplasia? What is the best known example?
- cryptorchidism
- endocrine disorder - reduced production of LH and FSH
Klinefelter’s syndrome (XXY) in tricolor male cats
Testicular hypoplasia, yearling ram:
- testes and epididymis are very small compared with normal-aged controls
- seminiferous tubules are lined only by Sertoli cells and there is no spermatogenesis
Tesitcular hypoplasia:
testicles/epididymis are small, but movable in the scrotum
- not apparent until after puberty
What is testicular degeneration and atrophy? What is it the most common cause of?
testes that reduce in size AFTER puberty
infertility
What 7 things is testicular degeneration/atrophy commonly secondary to?
1 epididymitis/scrotal diseases**
2. trauma
3. partial loss of blood flow
4. advancing age
5. chemotherapy
6. hormones
7. neoplasia
How does testicular degeneration/atrophy present? What is important to note in young, growing males?
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
Testicular degeneration/atrophy:
fibrosis!
How is testicular hypoplasia and degeneration/atrophy typically differentiated?
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
Why is true orchitis rare? What are the 4 portals of entry for orchitis?
usually associated with epididymitis
- HEMATOGENOUS = Brucella aborus in bulls; C. pseudotuberculosis and B. ovis in rams; B. suis in boars; B canis and Blastomyces dermatitidis in dogs
- DIRECT PENETRATION = bite wound, foreign body
- ASCENDING INFECTION** = E. coli, Proteus, Staph/Strep, Histophilus, Actinobacillus seminis
- PERITONEAL (periorchitis) - FIP in cats, peritonitis
Orchitis, Brucellosis:
When is it common in pigs for peritoneal spread to cause orchitis?
Glasser’s disease
What are the 2 most common types of epididymal disorders?
DEVELOPMENTAL: aplasia/hypoplasia, spermatic granuloma
INFLAMMATORY: infectious, non-infectious (spermatic granuloma)
In what species is segmental aplasia/hypoplasia in the epididymis most common? What 3 things does it typically lead to?
bulls —> involving the body and the tail (usually unilateral)
- back pressure and secondary testicular degeneration
- sperm impaction secondary to obstruction
- dilatation (spermatocele) and/or rupture
What is a spermatic granuloma? What are 3 causes?
epididymal rupture with extravasation of spermatozoae to the interstitium leading to a granulomatous response
- congenital = epididymal head due to blind-ended efferent ductules
- mechanical trauma = anywhere
- secondary to epididymitis = anywhere
Spermatic granuloma:
mass of spermatozoa in the interstitial CT of the epididymis is surrounded by macrophages and multinucleated giant cells
What are the noninfectious causes of epididymitis? Infectious?
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
Epididymitis, dog:
Epididymitis, Brucella ovis:
Necrotizing epididymitis and orchitis:
B. suis
In what species are testicular tumors most common? What are the 3 most common?
+++ 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
How do interstitial (Leydig) tumors typically present? What are commonly also seen?
tan to yellow-orange, well-demarcated, soft, and spherical
- cysts
- hemorrhage
How do Sertoli cell tumors typically present? When are they most common?
firm (abundant stroma), white, and round to multilobulated
cryptorchid canines
What hormone do Sertoli cell tumors typically produce? What 4 things does this commonly cause?
estrogens
- feminization - gynecomastia, penile and testicular atrophy, loss of libido
- alopecia
- bone marrow suppresion - anemia, leukopenia, thorombocytopenia
- prostatic disease - squamous metaplasia
Sertoli cell tumor presentation:
Where are seminomas derived from? How do they typically present?
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
How do seminomas compare to other testicular neoplasms?
tend to be more invasive and metastatic potential cannot be predicted
Seminoma, stallion:
metastasis to splenic lymph nodes
What are teratomas? In what species are they most common?
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
What is a varicocele? In what species are they most common? What does this commonly cause?
dilation of the spermatic veins in the pampiniform plexus
older rams
- thrombosis
- affects thermoregulation and can lead to testicular degeneration
Varicocele:
- larger than testis
- multinodular from large thromboses filling the dilated veins
When is torsion of the spermatic cord common?
- cryptorchid testicles
- testicles with neoplasms
When is inflammation of the spermatic cord (funisitis) most common?
following contamination of castration wounds
In what animals is vesicular adenitis most common? How is it diagnosed?
bulls
rectal palpation
What is the main form of vesicular adenitis? What are the most common infectious causes?
chronic interstitial form - markedly enlarged and firm
Brucella, Staph/Strep, Mycoplasma, T. pyogenes
In which animals is prostatitis most common? What is it associated with?
older, intact dogs
prostatic hyperplasia or squamous metaplasia (Sertoli cell tumor)
What are the 2 most common causes of prostatitis?
- ascending infection from the urinary tract epithelium - Proteus, E. coli, Staph/Strep
- hematogenous - Brucella canis
How does prostatitis afftect the animal?
- can compress ureters, leading to LUTI and pyelonephritis
- can compress the colon and cause constipation
Prostate hyperplasia:
Prostatitis:
Prostatitis + urinary bladder:
Prostatitis, colon compression:
From what 2 places do prostatic neoplasias typically arise from? In what animals is this most common?
- prostatic epithelium (ducts and acini)
- urethral epithelium (urothelial)
dogs > 10 years old
What are the 2 important features of prostatic neoplasia?
- frequently metastasizes, especially to bone
- causes asymmetrical enlargement
Prostatic carcinoma:
asymmetrical enlargement of affected kidney
Prostatic carcinoma:
- assymetric enlargement
- focal white areas are regions of necrosis
- gland is enlarged due to neoplastic epithelial cells
What is the difference between balanitis, posthitis, and balanoposthitis?
BALANITIS = inflammation of the head (glans) of the penis
POSTHITIS = inflammation of the prepuce
BALANOPOSTHITIS = inflammation of the glans and the prepuce
What 3 diseases most commonly affect the penis?
- equine coital exanthema - equine herpesvirus-3
- infectious balanoposthitis - bovine herpesvirus-1
- ulcerative posthitis in castrated rams - Corynebacterium renale
Ulcerative balanoposthitis:
equine coital exanthema
- equine herpesvirus-3
Bovine infectious balanoposthitis:
bovine herpesvirus-1
What are 2 major causes of ulcerative posthitis in castrated rams?
- castration leads to these animals urinating within their prepuce
- diets rich in protein have high concentrations of urea, allowing Corynebacterium renale to break it down into ammonia, which is cytotoxic
What tends to cause granulomatous balanoposthitis in horses?
Habronemiasis
What 3 neoplasias are most common in the penis and prepuce?
- penile squamous cell carcinoma in horses
- fibropapilloma of bulls
- canine TVT
Where does penile squamous cell carcinoma arise? What previous infection can also cause it to arise?
sheath of the penis of older horses (stallions = geldings)
papillomas caused by Equus caballus papillomavirus type 2 (EcPV2)
How do penile squamous cell carcinomas present?
medium to large tumors with areas of ulceration
Penile squamous cell carcinoma:
At what age are fibropapillomas most common in bulls? What causes it? How does it typically present?
young bulls, 1-2 years
bovine papillomavirus 1 and 2
exophitic mass that typically spontaneously regresses
Fibropapilloma of bulls:
How does canine TVT typically present? How are they aquired?
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)
How does canine TVT typically progress? What does it involve when it metastasizes?
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
