Scrotum Flashcards
What does a normal testis look on US?
Homogeneous medium-level echo texture
What surrounds the testicle?
Tunica albuginea (fibrous capsule)
What makes up the mediastinum testis?
Multiple septations (septula) from the tunica albuginea
What do the wedge-shaped compartments formed by septula contain?
Seminiferous tubules
List the flow of sperm through the testis.
Seminiferous tubules > Tubuli recti > Rete testis > Efferent ductules > Ductus Epididymis > Vas deferens
What is the rete testis?
Anastomosing network of delicate tubules located in the hilum of the testicle that carries sperm to the epididymis
What do the efferent ductules do?
Carry seminal fluid from rete testis to the epididymis
What are the different parts of the epididymis?
Head, body and tail
How does the epididymis appear on US?
Isoechogenic, or slightly hyperechoic than the testis
What is the appendix testis?
Remnant of the Mullerian duct; small ovoid structure located beneath the head of the epididymis
What is the appendix epididymis?
Detached efferent duct, small stalk projecting off the epididymis; derived from the Wolffian duct
What is the dartos?
Layer of muscle fibers lying beneath the scrotal skin dividing the scrotum into 2 chambers
What are the scrotal raphe?
The 2 scrotal chambers
What is the tunica vaginalis?
Saccular extension of the peritoneum into the scrotal chambers
Which layer of the tunica vaginalis covers the testis and epididymis?
Inner or visceral layer
What layer of the tunica vaginalis lines the scrotal chamber?
Outer or parietal layer
What supplies the testicular blood flow?
Deferential artery
Cremasteric (external spermatic) artery
Testicular artery
What does the testicular artery branch into?
Capsular and centripetal arteries
What does the spermatic cord consist of?
Vas deferens Cremasteric, deferential, testicular arteries Pampiniform plexus of veins Lymphatics Nerves
Which testicular lesions are malignant?
Intratesticular
How do malignant testicular neoplasms appear on US?
Hypoechoic compared to normal testicular parenchyma
What is the most common germ cell tumor?
Seminoma
What are risk factors for seminomas?
Cryptotorchidism FamHx Infertility Klinefelter syndrome Down syndrome Smoking Caucasian
What tumor markers should be evaluated for germ cell tumors?
Beta-hCG
AFP
LDH
Where should one look for lymph nodes when a seminoma is discovered?
Paraaortic
What other cell types do nonseminomas contain?
Embryonal carcinomas
Teratomas
Yolk sac tumors
Choriocarcinomas
Where does lymphatic mets occur in nonseminomas?
Retroperitoneal nodes
What is the most common testicular tumor in infants and young boys?
Yolk sac tumors
What is a Leydig cell tumor?
Rare stromal testicular tumor in boys (5-10yo) and men (30-60yo)
What do Leydig cell tumors produce?
Testosterone resulting in precocious puberty
Which lab marker is indicative of nonseminomatous tumor?
Alpha-fetoprotein
What are the 2 types of benign testicular cysts?
Cysts of tunica albuginea
Intratesticular cysts
What is an epidermoid cyst?
Benign tumor of germ cell origin
Well-circumscribed solid tumors lying beneath tunica albuginea
How do epidermoid cysts appear on US?
Well-defined, solid hypoechoic mass with an echogenic capsule or onion ring pattern
How do testicular abscesses appear on US?
Enlarged testicle carrying predominantly fluid-filled mass with hypoechoic or mixed echogenic areas
How does a testicular infarct appear on US?
Depends on age of infarct
Initial- focal or diffuse hypoechoic testicle
Then testicle decreases in size with increased echogenicity
What is a hydrocele?
Serous fluid that accumulates within the tunica vaginalis or between its layers
What is a hematocele?
When blood fills the scrotal chamber associated with trauma
What is a varicocele?
Dilatation of the pampiniform venous plexus of the testicular veins which drain the testicle
Where are 90% of varicoceles located?
The left side because of the length of the left testicular vein as it drains into the left renal vein
What are causes of unilateral scrotal pain?
Testicular torsion
Epididymitis
Varicocele thrombosis
What is the most common correctable cause of male infertility?
Varicocele
What is a scrotal hernia?
Bowel protruding through the inguinal canal into the tunica vaginalis
What structure do extratesticular tumors involve?
Epididymis
What is the most common extratesticular tumor?
Adenomatoid tumor
What are spermatoceles?
Cystic masses of the epididymis that result from dilatatian of the epididymal tubules
What are more common - spermatoceles or epididymal cysts?
Spermatoceles
How do spermatoceles appear on US?
Anechoic, well-defined masses with no or few internal echoes
Usually occur at the epididymal head
What is the differential diagnosis of the acutely painful scrotum?
Testicular torsion Trauma Epididymitis/orchitis Incarcerated hernia Torsion of the appendix testis Varicocele thrombosis
What is the most common condition that causes acute scrotal pain?
Acute epididymitis
What usually causes acute epididymitis in men under 35 years of age?
Chlamydia and gonorrhea
What usually causes acute epididymitis in prepubertal boys and men older than 35 years of age?
Urinary tract infections
How does epididymitis appear on ultrasound?
Enlarged hypoechoic epididymis
Increased blood flow (hyperemia)
Reactive hydrocele
Scrotal wall thickening
What are sonographic findings of orchitis?
Enlarged hypoechoic testicle
Increased blood flow (hyperemia)
Decreased arterial resistance
What congenital anomaly causes the testicle to twist causing testicular torsion?
Lack of attachment from the testicle to the tunica vaginalis
At what time period does the testicle become enlarged and hypoechoic in testicular ischemia?
Six hours
What will better optimize slow blood flow to rule out a complete torsion?
Decreasing pulse repetition frequency (color scale)
What is cryptorchidism?
Hidden testicle and generally refers to an undescended testicle
What are complications of cryptorchidism?
Infertility
Malignancy
What is the most common location of the cryptorchid testis?
Inguinal canal or pre-scrotal positions
How rare is anorchia or congenital absence of testicle?
4% of patients with cryptorchidism
