MEDI7302 Study Guide - Final Guide: Etiology, Vasculitis, Development Of The Gonads
Testicular Conditions
Learning
objectives
Describe the embryology/developmental basis for an undescended testis and
potential complication of this condition.
Describe the anatomy of the testes and spermatic cord including blood supply
and lymphatic drainage.
Understand the appropriate steps for examination of the scrotum and other
associated regions e.g. inguinal lymph nodes and groin.
Recognize the acute scrotum and contrast the presentation, investigation and
management of epididymo-orchitis and testicular torsion
Outline the presentation, appropriate investigation and management of scrotal
lumps including hydrocele, varicocele, epididymal cysts, testicular tumour and inguinoscrotal
hernia.
Male genital
system
Testis/
epididymis
Testes (site of sperm production & hormone synthesis) &
epididymis (site of sperm storage) are paired structures located within the
scrotum
Location
Testes are located within scrotum with epididymis
sitting on the posterolateral aspect of each testicle; testes are
suspended from abdomen via spermatic cord
Testis arise from the mesodermal germinal ridge in the
posterior abdominal wall
During embryonic development, testes enlarge and
descend from posterior abdominal wall through the inguinal canal to
the scrotum along with neurovascular supply
During testicular descent, a prolongation of peritoneum
called processus vaginalis projects into foetal scrotum and covers
anterior and lateral aspects of testis -> it should obliterate at time of
birth, leaving the tunica vaginalis behind
Structure
Ducts: seminiferous tubules (contained in lobules) ->
rete testes -> efferent tubules -> epididymis
Testes has two coverings
oTunica vaginalis (externally) derived from
abdominal peritoneum in development
oTunica albuginea (fibrous capsule) that encloses
testes and penetrates within to divide it into lobules
Epididymis has three parts - head, body, tail
Neurovascular
Testicular plexus - autonomic and sensory fibres to
testes and epididymis
Testicular arteries (via abdominal aorta) - supply testes
and epididymis
Testicular veins within pampiniform plexus inside
scrotum (drain into testicular veins -> IVC)
Lumbar and para-aortic nodes
Scrotum Bilateral fibromuscular cutaneous sacs fused at midline via
scrotal raphe
Contents
Testis
Epididymis
Spermatic cord
Dartos muscle (SM) - immediately underneath skin, it
aids temperature regulation via wrinkling skin (decrease SA, reduce
heat loss)
Neurovascular
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Anterior scrotal arteries (via external pudendal artery)
and posterior scrotal arteries (via internal pudendal artery)
Scrotal veins (drain into external pudendal veins)
Multiple cutaneous innervative nerves
oGenital branch of genitofemoral
oAnterior scrotal nerves
oPosterior scrotal nerves
oPerineal branches of posterior femoral
cutaneous nerve
Superficial inguinal nerves
Spermatic
cord
It passes through inguinal canal via deep and superficial inguinal
rings to enter scrotum
Fascial layers
External spermatic fascia (via aponeurosis of external
oblique)
Cremaster muscle and fascia (via internal oblique +
aponeurosis)
Internal spermatic fascia (via transversalis fascia)
Contents
3 arteries Testicular artery
Cremasteric artery
Artery to ductus deferens
3 nerves Genital branch of genitofemoral nerve
SNS and visceral afferent fibres
Ilio-inguinal (it runs outside spermatic
cord, but alongside it)
3 other Pampiniform plexus
Ductus deferens
Lymphatics
Processus vaginalis
Scrotal
examination
Examine patient in warm, relaxed environment
General inspection
Penis, groin, lower
abdomen
Observe
Skin changes - rash, bruising, swelling,
erythema, hair loss
Scars - px hernia or orchidopexy
Obvious mass
Scrotum Ask patient to hold penis out of way
Inspect front, sides and posterior aspect by lifting
scrotum + perineum
Observe
Skin changes - rash, ulcer, erythema (eg
cellulitis, fungal infection)
Scars - px vasectomy or orchipexy
Masses
Swelling - bilateral or unilateral, any
erythema
Bruising
Necrotic looking tissue (Fournier's
gangrene)
Palpation
Penis Retract foreskin to check for phimosis (narrow
foreskin), adhesions, glans abnormalities (ulcer, discharge, scars)
Open urethral meatus to check for patency
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Replace foreskin after examination to prevent
paraphimosis (retracted foreskin obstructs venous return)
Testicles Examine each individual testicle
Use both thumb and index fingers in gentle
rubbing motion with remaining fingers behind to immobilise it
If testicle is not located, follow path of
inguinal ligament for undescended testicle OR look for scar
suggesting previous orchidectomy or orchidopexy
Mass - size/ shape, regularity, consistency
(hard is solid, soft is cystic, bag of worms is varicocoele),
discomfort, mobile (non-moveable indicates inguinal hernia),
cough impulse (+ve is hernia/ varicocoele), transillumination (+ve
suggests fluid filled eg hydrocoele)
oSeparate mass to testicle + solid =
epididymitis/ orchitis
oSeparate mass to testicle + cystic =
epididymal cyst/ spermatocoele
Epididymis Pain with palpation suggests epididymitis
Phren's test - if testicular pain is alleviated by
elevating testes, it strongly suggests epididymitis
Cremaster reflex - stroking medial thigh leaks to
testicles elevation; absence suggests testicular torsion
Spermatic
cord
Palpate for tenderness and masses
Inguinal
lymph nodes
Size - insignificant if <3cm
Consistency - soft (insignificant), rubbery (classically
lymphoma), hard (classically malignancy & granulomatous infection)
Tender (classically infection) vs non-tender
(classically malignancy)
Assessment (standing)
Inspect and palpate for varicocoele (bag of worms) or hernia (mass)
Undescended
testes
(cryptorchidism)
Most common genital problem encountered in paediatrics
Embryology
After 6wks gestation, the testis-determining SRY gene on chromosome Y
directly affects differentiation of indifferent gonads -> testis
Around 6-7wks gestation, Sertoli cells secrete anti-Mullerian hormone
leading to regression of female reginal organs
Around 9wks gestation, Leydig cells secrete testosterone to promote
development of Wolffian ducts -> male genital tract components AND concurrently, the
testis organizes itself into a distinct organ (seminiferous tubules surrounded by tunica
albuginea)
Testes remain in retroperioneal position until 28wks whereby inguinal
descent of testicle begins, completing by 40wks gestation
Pathophysiology (all theories)
Main issue Testis follows normal course of descent but
stops short of scrotum, lying anywhere from abdominal
cavity/inguinal canal/ proximal scrotum
Gubernaculum
abnormalities
Gubernaculum is a structure connecting
lower aspect of tunica vaginalis ---> base of scrotum
It aids testicular descent via widening
inguinal canal & guiding testis down into scrotum
Reduced intra-
abdominal pressures
Prune belly syndrome, gastroschisis (both
have decreased intra-abdominal pressures)
Theory based on reduced pressures does
not explain most cases of cryptorchidism
Intrinsic testicular or
epididymal
Germinal epithelium of undescended testis
may be histologically abnormal
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Document Summary
Describe the embryology/developmental basis for an undescended testis and potential complication of this condition. Describe the anatomy of the testes and spermatic cord including blood supply and lymphatic drainage. Understand the appropriate steps for examination of the scrotum and other associated regions e. g. inguinal lymph nodes and groin. Recognize the acute scrotum and contrast the presentation, investigation and management of epididymo-orchitis and testicular torsion. Outline the presentation, appropriate investigation and management of scrotal lumps including hydrocele, varicocele, epididymal cysts, testicular tumour and inguinoscrotal hernia. Testes (site of sperm production & hormone synthesis) & epididymis (site of sperm storage) are paired structures located within the scrotum. Testes are located within scrotum with epididymis sitting on the posterolateral aspect of each testicle; testes are suspended from abdomen via spermatic cord. Testis arise from the mesodermal germinal ridge in the posterior abdominal wall.
