Scrotum & Prostate

Verumontanum

The junction of the ejaculatory ducts with the urethra

Peripheral Zone

The largest zone in the prostate, containing 70% of the glandular tissue; the most lateral portions of the prostate; found lateral and and posterior to the urethra; Most cancers arise here

Central Zone

Forms about 20% of the prostate bordering seminal vesicles 

Transition Zone

Located on the lateral sides of the proximal urethra; where BPH occurs

Ejaculatory ducts

descend inferiorly through the posterior portion of the gland and open into the prostatic urethra 

BPH

Benign prostatic hypertrophy; common in older men; constricts the urethra

Seminal fluid

Produced by the prostate, seminal vesicles, and Cowpers gland

PSA

Serum prostatic specific antigen; used to evaluate the function of the prostate; levels nearing 10 are always suspicious for pathology

*levels will rise with the age of the pt.

Adenocarcinoma

The most common malignant neoplasm of the prostate

Seminal vesicles

Superior and slightly posterior to the prostate

NL size of the prostate

4 × 3 × 4cm

PSA density formula

= PSA/ gland volume

Hydroceles

Located between the two layers of tunica vaginalis; SA: anechoic fluid filled in the scrotal sac surrounding testicles and epididymis, may contain debris or septations

CI: Asymptomatic or pt. c/o of scrotal enlargement

Cryptorchidism

Undescended testicle, typically seen in newborns; cannot be brought into the scrotum with external manipulation; 80% of cases, the testis is found in the inguinal canal; high risk for cancer and infertility

SA: smaller and less echogenic, oval and homogenous, mediastinum usually not seen

CI: Asymptomatic or palpable mass in the pelvic/ groin region

Epididymitis

infection of the epididymis

SA: enlargement, hypoechoic gland, increased vascularity

CI: scrotal pain/ possible discharge

Normal appearance of the testis

smooth, homogeneous, echogenic, ovoid shape

Best scanned from superior to inferior

Normal appearance of the epididymis

Normal finding: shows little flow with color doppler

Undescended testis

SA: smaller and less echogenic than the normal testis

*more likely to develop cancer

Lymphoma

SA: decreased echogenicity; patchy-looking; “liver that’s focal sparing”

CI: Pt. may experience wt. loss, anorexia, & weakness

Testicle may become enlarged

Diffuse orchitis

SA: decreased echogenicity, and vascularity throughout entire testicle

CI: pain, fever, nauseas, vomiting

*almost always occurs secondary to epididymitis

Infarction

Tissue death due to lack of blood flow

SA: hypoechoic wedge shaped area

CI: decreased or complete absence of doppler

*if entire testis in infarcted, findings cannot differentiate from testicular torsion

Hydrocele image

Can have a “snow globe” like appearance, or largely septated loculations

Germ Cell Tumors

Type of testicular tumor that is typically highly malignant

Associated with elevated HCG & AFP levels

Seminoma

SA: solid/homogeneous, hypoechoic masses with a smooth border

*The most common germ cell tumor

Embryonal cell tumor

Second most common germ cell tumor; more aggressive than seminomas, invading the tunica albuginea

SA: heterogeneous, poorly circumscribed *may contain echogenic areas/ calcifications

Teratocarcinoma

Third most common germ cell tumor, MALIGNANT

teratomas

lesser common germ cell tumor; benign in children; may show dense foci that produce acoustic shadowing

microlithiasis

An uncommon condition characterized by tiny calcifications within the testis; typically smaller then 3mm; occurring bilaterally

SA: multiple tiny echogenic foci throughout the testicle, w/ or w/o shadowing “speckling”

rete testis

Tiny tubular structure in the mediastinum, located at the hilum of the testis; drains into the head of the epididymis through the efferent ducts

epidiymis

Tubular structure beginning superiorly and courses posterolateral to the testis; the head is the largest part; reservoir for sperm

mediastinum testis

vertical septum; supporting structure for vessels

SA: thin echogenic line

spermatic cord

contains the vas deferens, testicular arteries, venous pampiniform plexus (veins), & lymph vessels

tunica albuginea

Dense/ fibrous tissue that completely covers the testicle

tunica vaginalis

Lines the inner walls of the scrotum, covering each testis and epididymis; consists of two layers

Parietal & Visceral layers

Two layers that comprise the tunica vaginalis:

1. visceral- surround the testis and epididymis

2. Parietal- inner layer of the scrotal wall

*hydroceles form between these two layers; it is normal to see a small amount of fluid here

testicular arteries

Both LT and RT arteries arise from the abdominal AO just below the renal arteries; primary source of blood flow to the testis

Vascular flow

Lobules—> tubules—> straight tubules—> rete testi (in the mediastinum)—> efferent ducts—> epididymal head/body/tail—>vas deferens (spermatic cord)

Pampiniform plexus

venous drainage of the scrotum

optimal pt positions for exam

1. Supine

2. upright position used to check for varicoceles

   **or valsalva maneuver

Performing an exam

It is best to perform a brief survey scan to determine what abnormalities are present; each testis is scanned from superior to inferior

Varicoceles

Abnormal dilation of the veins within the spermatic cord; caused by incompetent venous valves; more commonly on the left due to drainage of the spermatic vein into the left renal vein; LRV can become compressed between SMA and AO

Hernnia

occur when bowel, omentum, or other structures herniate into the scrotum; the bowel is the most common herniated structure; peristalsis of the bowel confirms the diagnosis of a scrotal hernia

Rare varicoceles

rare in the testicle

mediastinum

posterior portion of the tunica albuginea

Testicular microlithiasis

tiny echogenic foci throughout testis; with or without shadowing

Abscess

Increased WBC, fever, variable mass with irregular borders

Labeling testicle