Pathology of male genital tract

Question 1

Scrotum

Answer 1

scrotum - changes often with dermatitis elsewhere - eg chorioptic mange in rams

Question 2

Scrotum + tunica vaginalis - neoplasia

Answer 2

varicose haemangioma - dog + boar. proliferation of blood vessels
melanomas
mast cell tumor - dog
haemangiosarcoma - dog
papilloma - boar

Question 3

Tunica vaginalis

Answer 3

layer of mesothelium continuous with peritoneum - peritoneal disease can spread
hydrocoele in ascites
adhesions with epididymitis/orchitis or penetrating wounds
tumours are v.rare

Question 4

testis + epididymis

Answer 4

developmental anomalies
degeneration
inflammation
neoplasia

Question 5

intersex conditions

Answer 5

most cases are pseudohermaphrodites - external female genitalia with testes in place of ovaries
true hermaphroditism is rare - animals have 1 ovary and 1 testis or combined

Question 6

cryptorchidism

Answer 6

usually unilateral
side depends on species
testis retained anywhere from kidney to inguinal canal
likely polygenic basis but also hormonal/environmental factors
cryptorchid testes tend to be small + fibrotic
interstitial collagen, only few spermatogonia
increased risk of tumour

Question 7

testicular hypoplasia

Answer 7

all species
congenital or pre-puberty
often not seen until after puberty
unilateral or bilateral
small but normal in consistency
incomplete or absent spermatogenesis with hypoplastic + normal tubules often intermingled

Question 8

Testicular atrophy/degeneration

Answer 8

testes reduce in size after puberty
causes - inc scrotal temp, dec testicular blood supply, vit A or zinc deficiency, drug reaction, radiation
unilateral or bilateral
testes reduced in size + firm on palpation
micro changes similar to hypoplasia but include fibrosis + granuloma formation
multinucleate spermatids may be seen

Question 9

Orchitis

Answer 9

v.rare
causes: haematogenous - purulent, results in progressive fibrosis
trauma - mainy dogs due to bites + accompanied by periorchitis + epididimytis
reflux orchitis as extension of infl from epididymis, prostate, bladder or urethra - mixed infections
in severe can causes sterility
often spermatic granulomas

Question 10

epididymitis

Answer 10

more common than orchitis esp. ram and dog
ascending infection from accessory sex glands + urogenital tract
initial enlargement with later abscess + granuloma formation
mostly unilateral
spermatic granuloma of epididymal head
some degree of testicular atrophy
most cases are mixed infections

Question 11

infectious epididymitis - ram

Answer 11

haematogenously - e.g brucella ovis
ascending
swelling + spermatic granuloma formation esp. in tail of epididymitis

Question 12

testicular neoplasia

Answer 12

most important in dogs
3 main types - interstitial, sertoli cell tumours, seminoma
mixed tumours share features of more than 1 type

Question 13

interstitial cell tumours

Answer 13

occur commonly in dogs over 8 y/o
single or multiple spherical, well demarcated, tan-orange greasy or haemorrhagic mass which bulge on cut surface
don’t causes enlargement of testes - replaces existing tissue
biopsy reveals polyhedral cells
most are benign
some secrete hormones - causes aggression

Question 14

sertoli cell tumour

Answer 14

occur in dogs over 6 y/o
50% in cryptorchid testes
unilateral, firm lobulated discrete mass
testicular enlargement
on cut surface, colour varies from white to brown, is often fibrous + may have cysts
microscopy reveal sertoli cells multilayered within tubules or invading interstitial tissue
metastasis in 10% of cases - to scrotal LN
25% secrete oestogen

Question 15

sertoli cell tumour + feminisation

Answer 15

some make oestrogen, many inhibin
female distribution of fat
attractive to other male dogs
mammary swelling
pendulous sheath
symmetrical alopecia + thinning of skin
atrophy of other testis
squamous metaplasia of prostate gland
behavioural changes
anaemia due to depression of bone marrow

Question 16

seminoma

Answer 16

derived from spermatogonia 
dogs over 7 y/o
usually unilateral + single
may cause swelling and pain
soft cream mass, bulges on cut section
sheets of polyhedral cells with large nucleus + thin rim of cytoplasm
mitoses common in some tumours
local invasiveness
most are benign
cann occur in retained testes

Question 17

teratoma

Answer 17

mostly horses,usually young
tumour from all 3 germ cell layers
quite large + are admixture of solid + cystic areas
mixture of skin, bone, teeth, glands, muscle + cartilage - most have nervous tissue + fat
most are benign

Question 18

Funicuitis

Answer 18

inflammation of spermatic cord
seen following open castration
common in pigs
generally acute and necrotising
horses - 'scirrhous cord' after open castrate. lots og granulation tissue in affected cord. open weeping. caused by staph. and strep.

Question 19

pathology of accessory sex glands

Answer 19

infl of seminal vesicles + bulbourethral glands occurs mostly in bulls + rams
chronic interstitial infl
metaplasia common

Question 20

pathology of prostate gland - hyperplasia

Answer 20

older entire dogs
commonly causes constipation + can cause urinary stasis
enlarged gland
papillary proliferation of glandular tissue
castration causes atrophy

Question 21

pathology of prostate gland - metaplasia

Answer 21

change of glandular epithelium to squamous
dog with sertoli cell tumours + predisposes to inflammation
cattle/sheep associated with oestrogenic implants + ingestion of phytoestogens
squamous metaplasia also occurs in bulbourethral glands of wethers

Question 22

pathology of prostate gland - prostitis

Answer 22

not uncommon in dogs
in older dogs often together with hyperplasia
usually due to coliforms, strep., staph., that invade prstatic urethra
asymmetrically englarged and may have abscesses
untreated may develop peritonitis or septicaemia/taxaemia
chronic cases may be subclinical

Question 23

pathology of prostate gland - neoplasia

Answer 23

carcinoma in dogs
may occur in hyperplastic gland
grossly the gland is asymmetrically enlarged
multiple layers of haphazardly arranged glandular cells invading the interstitium of the gland and often causing marked fibrosis
80% have spread by time of discovery

Question 24

pathology of penis and prepuce

Answer 24

tritrichomonas foetus - infertility/early embryonic death/abortion/pyometra in female cow
camplylobacter foetus ssp veneralis - infertility/early embryonic death/abortion in female cow
herpesviruses
papillomaviruses

Question 25

pathology of penis and prepuce - anomalies

Answer 25

hypoplasia in early castration + intersex states
directional deviations in various species
persistent frenula esp. bulls + boars
hypospadia/epispadia - abnormal opening of urethra

Question 26

pathology of penis and prepuce - inflammation

Answer 26

glans penis - balanitis
prepuce - posthitis
generally occur together - blanoposthitis
herpesvirus are a cause

Question 27

pathology of penis and prepuce - bacteria

Answer 27

sheep - ulecerative prosthitis - corynebacterium renale. predisposed by hypoplasia of penis/prepuce, urinary soiling + high planes of nutrition. yellowish discolouration + ulceration. if severe may slough. secondary infection common

Question 28

pathology of penis and prepuce - parsites

Answer 28

cutaneous habronemiasis in horses: exuberant granulation following deposition of larvae in this region

Question 29

pathology of penis and prepuce - neoplasia

Answer 29

squamous cell carcinoma: v important in horses (can occur in other species)
associated with novel papillomavirus
cauliflower like - variable size
malignant squamous cell epithelium forming keratin
usually low-grade malignancy - distant malignancy rare
will recur if incompletely removed
problems relate to ulcers + 2ndary infection

Question 30

fibropapilloma of the penis

Answer 30

occurs on glans penis - 1-2 y/o bulls
benign but may be large/multiple
caused by bovine papillomavirus
regresses with age
complications can involve 2ndary infection or penile obstruction

Question 31

transmissible venereal tumour

Answer 31

rare in dogs in the UK
principally on caudal portion of penis
seen also on skin at site of wounds
xenotransplantation
histiocytic origin with 59 instead of 78 chromosomes
variable size, cauliflower like
problems relate to ulcers + 2ndary infection
metastasis rare + regression often occurs