Male reproductive pathology

Question 1

Describe cryptorchidism (small testis)

Answer 1

Incomplete descent of testis

Retained between kidney & inguinal canal

Likely polygenetic basis

Often hypoplastic

Increased risk of tumour formation

Question 2

Describe testicular hypoplasia

Answer 2

Congenital or pre-puberty but not observed until after puberty

Causes:
- Nutritional (Zn def.), genetic, endocrine abnormalities

Mostly cattle, sheep & goats

Unilateral or bilateral

Hypoplastic but normal consistency

Microscopy: Absent/incomplete spermatogenesis with hypoplastic & normal tubules often intermingled

Question 3

Describe testicular atrophy/degeneration

Answer 3

After puberty

Common cause for male infertility

Unilateral or bilateral

Small & firm consistency (chronic)

Causes:
- infections, increased scrotal temp, decreased testicular blood supply, vit A/Zn deficiency, drug reactions, radiation damage, obstruction, hyperoestrogenism

Microscopy: absent/ incomplete spermatogenesis with hypoplastic and normal tubules often intermingled
+/- fibrosis, multinucleated spermatids

Question 4

Describe epididymitis

Answer 4

Important in rams (Brucella ovis - notifiable) & dogs

Affects tail of epididymis

Can cause secondary testicular degeneration/atrophy

Mostly ascending infection (accessory glands, urinary tract)

Can be haematogenous (rare)

Question 5

What condition is this?

Answer 5

Spermatic granuloma

Question 6

What condition is this?

Answer 6

Epididymitis

Question 7

In what animals is testicular neoplasia most common?

Answer 7

Older dogs & horses

Question 8

What are the 3 main primary types of testicular neoplasia?

Answer 8

1. Seminoma (germ cell tumour; also teratoma)
2. Interstitial (Leydig) cell tumour
3. Sertoli cell tumour

→ almost always benign!

May also occur in combination

Question 9

Describe seminoma (testicular neoplasia)

Answer 9

Derived from spermatogonia

Common in dogs & stallions

swelling & pain

Frequent mitoses

More prevalent in retained testes

Gross: cream bulging mass

Microscopy: polyhedral cells, large nucleus, thin rim of cytoplasm

Question 10

Describe Sertoli cell tumour (testicular neoplasia)

Answer 10

Common

50% in retained testes

Testicular enlargement

Around 1/3 secrete oestrogen &/or inhibin –> feminisation

Gross: firm white-brown lobulated mass, fibrous, cysts

Microscopy: sertoli cells multi-layered in tubules or invading interstitial tissue, abundant fibrous tissue

Question 11

Describe interstitial (Leydig) cell tumours (testicular neoplasia)

Answer 11

Common in dog, cat, bull

No enlargement of testes

Some produce hormones

Gross: single/multiple, spherical, tan/orange/haemorrhagic

Microscopy: polyhedral cells packed in small groups by fine fibrous stroma

Question 12

What are the most common prostatic diseases?

Answer 12

Hyperplasia > Inflammation > Neoplasia

Question 13

Describe prostatic hyperplasia

Answer 13

Old entire dogs

Constipation/urinary stasis

Castration causes atrophy

Caused by hormonal imbalance (testosterone & oestrogen influence)

Gross: bilaterally, symmetrically larger

Microscopy: hyperplasia & papillary proliferation of glandular tissue, stromal hyperplasia

Question 14

Describe prostatitis

Answer 14

If in older dogs, often together with hyperplasia

Mostly ascending bacterial infection

Untreated cases can develop into peritonitis or septicaemia/toxaemia

Chronic cases may be subclinical

Gross: asymmetrical enlargement +- abscesses

Microscopy: Infiltrated stroma, dilated glands, necrotic neutrophils, sloughed epithelial cells

Question 15

Describe prostatic carcinoma

Answer 15

Older dogs

Castration doesn’t prevent or treat

Metastasis common (lymph nodes, lungs, bone) –> poor prognosis

Clinical signs:
- constipation, urinary stasis, cachexia & locomotor abnormalities

Gross: asymmetrical mild enlargement

Microscopy: Haphazardly arranged glandular cells invading interstitium & marked fibrosis