the scrotum the scrotum2.pdfcopyright © 2012, 2006, 2001, 1995, 1989, 1983, 1978 by mosby, an...

Copyright © 2012, 2006, 2001, 1995, 1989, 1983, 1978 by Mosby, an imprint of Elsevier Inc.

THE SCROTUM

Copyright © 2012, 2006, 2001, 1995, 1989, 1983, 1978 by Mosby, an imprint of Elsevier Inc. 2

Anatomy of the ScrotumTESTES

n Symmetric, oval-shaped glands residing in the scrotum

n Adults: Testis measures 3-5 x 2-4 x 3 cm


Anatomy of the ScrotumTESTES

n Each testis divided into > 250 to 400 conical lobules containing the seminiferous tubules.

n Tubules converge at apex of each lobule and anastomose to form rete testis in mediastinum.

n Rete testis drains into head of epididymis through efferent ductules.

n Sonographically, testes appear as smooth, medium gray structures with fine echo texture.


Anatomy of the Scrotum


Anatomy of the ScrotumEPIDIDYMIS

n 6- to 7-cm tubular structure beginning superiorly and then coursing posterolaterally to testis

n Divided into head, body, and tail.

n Head is largest part, 6 to 15 mm in width.

n Located superior to upper pole of testis


Anatomy of the Scrotum EPIDIDYMIS



n Contains 10 to 15 efferent ductules from rete testis, which converge to form single duct in body and tail

n Duct known as ductus epididymis

n It becomes vas deferens and continues in spermatic cord.



n Body of the epididymis: Smaller than head

n Follows posterolateral aspect of testis from upper to lower pole

n Tail of the epididymis: Slightly larger and positioned posterior to lower pole of testis

n Appendix of the epididymis: Small protuberance from head of epididymis



n Normal epididymis

üIsoechoic or hypoechoic compared with testis

üEcho texture coarser


Anatomy of the Scrotum MEDIASTINUM

n Testis: Covered by dense, fibrous tissue termed tunica albuginea

n Posterior aspect of tunica albuginea reflects into testis to form vertical septum known as mediastinum testis


Anatomy of the Scrotum MEDIASTINUM

n Multiple septa (septa testis): Formed from tunica albuginea at mediastinum

n These septa course through testis and separate it into lobules

n Mediastinum supports vessels and ducts coursing within testis.

n Mediastinum often seen on sonography as bright hyperechoic line coursing craniocaudad within testis.



n Tunica vaginalis lines inner walls of scrotum, covering each testis and epididymis.

n Consists of two layers: parietal and visceral

üParietal layer is inner lining of scrotal wall

üVisceral layer surrounds testis and epididymis



n Small bare area, which is posterior.

n At this site, testicle is against scrotal wall, preventing torsion.

n Blood vessels, lymphatics, nerves, spermatic ducts travel through area.

n Hydroceles form in space between layers of tunica vaginalis.



n Vas deferens: Continuation of ductus epididymis

n Thicker and less convoluted

n Dilates at terminal portion near seminal vesicles

n Portion termed ampulla of the deferens

n Vas deferens joins duct of seminal vesicles to form ejaculatory duct, which empties into urethra.



n The junction of ejaculatory ducts with urethra is called the verumontanum.

n Urethra courses from bladder to end of penis.

n In men, urethra transports both urine and semen outside body.



n Vas deferens, testicular arteries, venous pampiniform plexus, lymphatics, autonomic nerves, and fiber of cremaster form spermatic cord

n Cord extends from scrotum through inguinal canal and internal inguinal rings to pelvis.

n Cord suspends testis in scrotum.


Vascular Supply

n Right and left testicular arteries arise from abdominal aorta below level of renal arteries.

n Capsular arteries give rise to centripetal arteries, which course from testicular surface toward mediastinum along septa.

n Before reaching the mediastinum, they curve backward forming recurrent rami (centrifugal arteries).

n Branch further into arterioles and capillaries


Vascular Supply


Vascular Supply

n Cremasteric and deferential arteries accompany testicular artery within spermatic cord to supply extratesticular structures.

n Have anastomoses with testicular artery and may provide some flow to testis

n Cremasteric artery branches from inferior epigastric artery (branch of external iliac artery).

n Provides flow to cremaster muscle and peritesticular tissue


Vascular Supply

n Deferential artery arises from vesicle artery (branch of internal iliac artery)

n Mainly supplies epididymis and vas deferens

n Scrotal wall also supplied by branches of pudendal artery.


Testicular Arterial Branching

n Testicular artery

n Capsular artery

n Centripetal artery

n Recurrent rami


Vascular Supply

n Venous drainage of the scrotum occurs through veins of pampiniform plexus.

n Pampiniform plexus exits from mediastinum testis and courses in spermatic cord.


Vascular Supply

n Pampiniform plexus converges into three sets of anastomotic veins:

1. Testicular

2. Deferential

3. Cremasteric


Vascular Supply

n Right testicular vein drains into inferior vena cava; left testicular vein joins left renal vein.

n Deferential vein drains into pelvic veins; cremasteric vein drains into tributaries of epigastric and deep pudendal veins.


Clinical Questions…

n Was this patient referred because of palpable mass, scrotal pain, swollen scrotum, or other reason?

n Ask patient to describe symptoms, including history, location, and duration of pain.

n Can he feel a mass? If so, ask patient to find lump. Place probe exactly over this location to examine site.

n Did patient experience trauma? When did trauma occur? Describe what happened.

n Vasectomy procedure? When?


Patient Positioning and Scanning Protocol

n Supine position

n Penis positioned on abdomen and covered with towel.

n Patient asked to place legs close together to provide support for scrotum.

n Rolled towel placed between thighs can support scrotum.



n Apply generous amount of warmed gel to scrotum.

n High-frequency probes (10 to 14 MHz)

n Bilateral exam, with asymptomatic side used as comparison for symptomatic side.

n Each testis scanned from superior to inferior.



n Size, echogenicity, and structure of each testis evaluated.

n Testicular parenchyma should be uniform with an equal echogenicity between sides.



n Is the parenchyma homogeneous or heterogeneous?

n Is there a mass? If so, is it cystic or solid?

n Is the mass intratesticular or extratesticular?



n Is one testis much larger than other? Is one side swollen, or is one side shrunken?

n Each testis should appear similar in size and shape. Is epididymis normal? Is skin thickened?

n Turn on color Doppler to assess flow. Is there an absence of flow in testis or is it hyperemic? How does color Doppler compare between sides?

n Check flow in each epididymis.



SAGITTAL IMAGE

n Spermatic cord arean Epididymal head with superior testisn Long axis mid testis with measurementn Medial long axisn Lateral long axis



TRANSVERSE IMAGE

n Spermatic cord arean Epididymal headn Superior testisn Mid testis with measurementn Inferior testisn Transverse view showing both testesn Color Doppler of epididymal headn Color Doppler of mid testisn Spectral Doppler of arteryn Spectral Doppler of vein


Sonographer Tips

n Explain procedure and preparation to patient; patient will get ready in private.

n Image of right and left testicle together for comparison in both gray scale and color Doppler

n Perform Valsalva maneuver when varicocele suspected.

n Sensitize color Doppler for slow flow when

evaluating torsion.


Technical Considerations

n Transducer selection

n Color Doppler and power Doppler

n Gain

n PRF

n Wall filter

n Line density

n Threshold

n Packet size


Scrotal PathologyACUTE SCROTUM

n Scrotal trauma presents challenge because scrotum often painful and swollen.

n Trauma may be result of MVA, athletic injury, direct blow to scrotum, or straddle injury.

n Determine if rupture present.


Scrotal Pathology ACUTE SCROTUM

n If surgery performed within 72 hours following injury, up to 90% of testes can be saved, but only 45% can be saved after 72 hours.

n Hydrocele and hematocele are both complications of trauma.

n Hematoceles contain blood; found in advanced cases of epididymitis or orchitis.



Sonographic findings associated with scrotal rupture:

ü Focal alteration of testicular parenchymal pattern

ü Interruption of tunica albuginea

ü Irregular testicular contour

ü Scrotal wall thickening

ü Hematocele



n Sonographic appearance of hematoceles varies with age.

n Acute hematocele is echogenic with numerous, highly visible echoes that can be seen to float or move in real time.

n With time, hematoceles show low-level echoes and develop fluid-fluid levels or septations.

n Presence of hematocele does not confirm rupture.



n Hematomas associated with trauma may be large and cause displacement of the associated testis.

n Hematomas appear as heterogeneous areas within scrotum.

n Become more complex with time, developing cystic components

n Hematomas may involve testis or epididymis, or they can be contained within scrotal wall.



n Blood flow disruption across surface of testis indicates rupture.

n Epididymitis may result from trauma; color Doppler imaging can be used to identify associated increased vascularity in epididymis.

n Torsion also associated with trauma.

n Color Doppler used to confirm absence of flow in testis with torsion.


Epididymo-orchitis

n Epididymo-orchitis is infection of epididymis and testis.

n Most commonly results from spread of lower

urinary tract infection via spermatic cord. n Most common cause of acute scrotal pain in

adults. n Usually occurs secondary to epidiymitis.


Epididymo-orchitis

Sonographic Findings

n Epididymitis appears as enlarged, hypoechoic gland.

n If secondary hemorrhage has occurred, epididymis may contain focal hyperechoic areas.

n Hyperemic flow confirmed with color Doppler.


Epididymo-orchitis


Epididymo-orchitis

n Normal epididymis shows little flow with color Doppler.

n Amount of color flow signal should be compared between sides.

n Affected side shows significantly more flow than asymptomatic epididymis.

n Important to use same color Doppler settings when comparing amount of flow between sides.


Epididymo-orchitis


Epididymo-orchitis

n Causes hyperemic flow with significantly more visible vessels on color Doppler compared with asymptomatic side.

n Hyperemic flow seen in epididymis and testis when both involved, but is restricted to epididymis only if testis is normal.


Epididymo-orchitis n Associated findings: Scrotal wall thickening and

hydrocele. n Hydroceles found around anterolateral aspect of testis. n These may appear anechoic or contain low-level echoes n Complex hydroceles may be associated with severe

epididymitis and orchitis. n These will have thick septations and contain low-level

echoes.


Epididymo-orchitis

n Severe cases: Pyocele may be present.

n Pyocele occurs when pus fills space between layers of tunica vaginalis.

n Usually contains internal septations, loculations, debris.

n Same appearance can occur following trauma or surgery.


n Testicular infarction may occur in severe cases of orchitis. n Swollen testis confined within rigid tunica albuginea. n Excessive swelling can cause obstruction to testicular

blood supply. n Color Doppler: Decreased or absent flow compared with

contralateral testis. n Decreased flow, spectral Doppler waveforms—high

resistance with little or no diastolic flow.

Epididymo-orchitis


Torsion

n Occurs as result of abnormal mobility of testis within scrotum

n Bell clapper deformity occurs when tunica vaginalis completely surrounds testis, epididymis, distal spermatic cord, allowing them to move and rotate freely within scrotum.


Torsion

n Testis and epididymis twist within scrotum, cutting off vascular supply within spermatic cord.

n Up to 60% of torsion patients have anatomic anomaly on both sides.

n Undescended testes are 10 times more likely than normal testes to be affected by torsion.


Torsion

n Compromises blood flow to testis, epididymis, and intrascrotal portion of spermatic cord.

n Venous flow affected first with occluded veins, causing swelling of scrotal structures on affected side.

n If torsion continues, arterial flow obstructed and testicular ischemia follows.


Torsion

n Torsion of spermatic cord is surgical emergency.

n If surgery performed within 5 to 6 hours of onset of pain, 80% to 100% of testes can be salvaged.

n Between 6 and 12 hours salvage rate is 70%.

n After 12 hours only 20% will be saved.


Torsion

n Torsion can occur at any age; peak incidence at age 14.

n Presenting symptoms: Sudden onset of scrotal pain with swelling on affected side.

n Severe pain causes nausea and vomiting in many patients.


Torsion


Extratesticular Masses

EPIDIDYMAL CYSTS, SPERMATOCELES, AND TUNICA ALBUGINEA CYSTS

§ Most scrotal cysts are extratesticular, found in tunica albuginea or epididymis.

üInclude spermatoceles, epididymal cysts, tunica albuginea cysts



n Spermatoceles are cystic dilatations of efferent ductules of epididymis.

ü Always located in epididymal head

ü Contain proteinaceous fluid and spermatozoa

ü May be seen more often following vasectomy



n Epididymal cysts are small, clear cysts containing serous fluid located within the epididymis.

n Epididymal cysts, spermatoceles, and tunica albuginea cysts are generally asymptomatic but may be palpable.


Epididymal Cysts


Varicocele

n A varicocele is an abnormal dilation of veins of pampiniform plexus (located within spermatic cord).

n Primary varicoceles usually caused by incompetent venous valves within spermatic vein.

n More common on left


Varicocele

n Secondary varicoceles are caused by increased pressure on spermatic vein.

n May be result of renal hydronephrosis, abdominal mass, or liver cirrhosis.

n Abdominal malignancy invading left renal vein may cause varicocele with noncompressible veins.


Varicocele

n Sonographic evaluation of varicocele shows numerous tortuous tubes of varying sizes within spermatic cord near epididymal head.

n Tubes may contain echoes that move with real-time imaging.

n Varicoceles measure > 2 mm in diameter.

n Tend to increase diameter in response to Valsalva maneuver.


Varicocele


Scrotal Hernia

n Scrotal hernias occur when bowel, omentum, or other structures herniate into scrotum.

n Clinical diagnosis usually sufficient; sonography helpful in cases of equivocal findings.

n Bowel most commonly herniated structure, followed by omentum.


Scrotal Hernia

n Peristalsis of the bowel, seen with real-time imaging, confirms the diagnosis of a scrotal hernia.

n See textbook Figure 23-24.


Hydrocele, Pyocele, and Hematocele

n Potential space exists between visceral and parietal layers of tunica vaginalis.

n This space is where a hydrocele, pyocele, or hematocele may develop.



n Hydroceles contain serous fluid.

n Are most common cause of painless scrotal swelling

n May be idiopathic, but commonly associated with epididymo-orchitis and torsion

n Pyoceles and hematoceles much less common than hydroceles.



n Pyocele is a collection of pus.

n Occur with untreated infection or when an abscess ruptures into space between layers of tunica vaginalis.

n Hematoceles are collections of blood associated with trauma, surgery, neoplasms, or torsion.


Sperm Granuloma

n Sperm granulomas occur as chronic inflammatory reaction to extravasation of spermatozoa.

n Most frequently seen in patients with history of vasectomy.

n Sperm granuloma may be located anywhere within epididymis or vas deferens .


Sperm Granuloma


Benign Testicular Masses

TUBULAR ECTASIA OF THE RETE TESTIS n Rete testis is located at hilum of testis where

mediastinum resides.

n Tubular ectasia of rete testis uncommon, benign condition.

n Associated with presence of a spermatocele,

epididymal, or testicular cyst or other epididymal obstruction on same side as dilated tubules


TUBULAR ECTASIA OF THE RETE TESTIS


CYST

n Cysts more common in men over 40 years of age.

n Associated with extratesticular spermatoceles

n Located near mediastinum

n Single or multiple and of variable size



CYST


MICROLITHIASIS

n Microcalcifications are < 3 mm.

n Usually bilateral condition

n Reported to have association with testicular malignancy; exact nature unknown.

n Microlithiasis has been associated with cryptorchidism, Klinefelter’s syndrome, infertility, varicoceles, testicular atrophy, and male pseudohermaphroditism.



MICROLITHIASIS


Malignant Testicular Masses

GERM CELL TUMORS n Testicular cancer is uncommon; accounts for only 1% of

cancers in men

n Is most common malignancy in men between ages of 15 and 35

n Is one of most curable forms of cancer

n Occurs most frequently between ages of 20 and 34

n Undescended testes are 2.5 to 8 times more likely to develop cancer.


GERM CELL TUMORS

n Symptoms: Painless lump, testicular enlargement, or vague discomfort in scrotum

n Primary goal: Determine mass location; differentiate between cystic and solid composition

n Extratesticular masses: Usually benign

n Intratesticular masses: More likely to be malignant


GERM CELL TUMORS

n Testicular tumors categorized as germ cell and non–germ cell tumors.

n Germ cell tumors: Associated with elevated level of human chorionic gonadotropin and alpha-fetoprotein.

n Approximately 95% of all testicular tumors are of germ cell type and highly malignant.

n Non–germ cell tumors are generally benign. n Most common type of germ cell tumor is seminoma,

followed by mixed embryonal cell tumors and teratocarcinomas.


GERM CELL TUMORS

n Sonographically, tumors appear as focal, hypoechoic masses.

n Embryonal cell tumors more aggressive than seminomas.

n Choriocarcinoma has varied sonographic appearance because of mixed cell types.


GERM CELL TUMORS

n Seminomas tend to be homogeneous, hypoechoic masses with a smooth border.

n They do not often contain calcification or cystic components.


GERM CELL TUMORS


Embryonal Cell Carcinoma

n Embryonal cell carcinoma is heterogeneous and less well circumscribed. It may contain areas of increased echogenicity resulting from calcification, hemorrhage, or fibrosis


Embryonal Cell Carcinoma

Cystic components are found in up to one third of embryonal cell carcinomas.


Choriocarcinoma

n Choriocarcinoma has a varied sonographic appearance because of mixed cell types.

n Its appearance is determined by the dominant cell type, but it typically has irregular borders.


Metastasis

n Metastasis to testicle is rare, normally occurring later in life.

n Primary tumor may originate from prostate or kidneys; less common sites include lung, pancreas, bladder, colon, thyroid, or melanoma.

n Metastasis to testicle is bilateral, with multiple lesions found.


Metastasis


n Solid hypoechoic mass

n Hyperechoic

n Mixture of both


Lymphoma and Leukemia

n Malignant lymphoma: 1% to 7% of all testicular tumors; most common bilateral secondary testicular neoplasm affecting men > 60 years.

n Leukemia involvement of testicle is next most common secondary testicular neoplasm; most often found in children.

n Testicle may become enlarged; tumor bilateral

or unilateral.


Congenital Anomalies

CRYPTORCHIDISM (UNDESCENDED TESTICLE)

n During fetal growth, testes first appear in retroperitoneum near kidneys.

n Testes should descend into scrotum from inguinal canal shortly before birth or early in neonatal period.


Cryptorchidism

n Undescended testis may be located in abdomen, inguinal canal, or other ectopic location.

n Testis usually found in inguinal canal; often palpable.

n Cryptorchidism is bilateral in 10% to 25% of cases.


Cryptorchidism


n Undescended testis: Smaller and less echogenic than normal testis

n Usually oval with homogeneous texture

n Mediastinum rarely seen.


Cryptorchidism


Testicular Ectopia

n Very rare condition

n Ectopic testicle cannot be manipulated into correct path of descent.

n Most common site for ectopic testicle to rest is superficial inguinal pouch.

n Other sites include perineum, femoral canal, suprapubic area, penis, diaphragm, and other scrotal compartment.


Anorchia

n Rare condition

n Unilateral anorchia, or monorchidism, found in 4% of patients with nonpalpable testis.

n More common on left side; definitive diagnosis depends on surgical diagnosis.

n Causes: Intrauterine testicular torsion or other forms of decreased vascular supply to testicle in utero.


Polyorchidism (Testicular Duplication)

n Very rare disorder; more common on left side (75%); bilateral in 5% of cases

n Testicular duplication: Usually found in scrotum; has also been found in inguinal canal or retroperitoneum.

n Increased incidence: Malignancy, cryptorchidism, inguinal hernia, torsion with polyorchidism

n Duplicated testis: Usually small; efferent spermatic system completely absent.

the scrotum the scrotum2.pdfcopyright © 2012, 2006, 2001, 1995, 1989, 1983, 1978 by mosby, an...

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