Testicular/Prostate Anatomy & Physiology

Intratesticular masses (benign and malignant), Most masses are ____ .

malignant; Malignant testicular tumor: intratesticular masses, especially if they are palpable, are likely to be malignant and must be surgically explored

PSA & its significance (carcinoma, BPH)

right column: elevated elevated: carcinoma, BPH

Microlithiasis & its sonographic appearance

Unusual condition diagnosed on testicular ultrasound •Found in between 1.5 to 5% of normal males, and may be found in up to 20% of individuals with subfertility •Asymptomatic, non-progressive disease •Cause is unknown, but this condition has been associated with testicular cancer •In a small group of individuals, cryptorchidism , mumps , infertility and intraepithelial germ cell neoplasia •Within the parenchyma of testicle •Multiple small calcifications Sonographic Findings: •Discrete, small, echogenic foci within testicle •Unilateral or bilateral •2mm - 3mm in size •No posterior shadowing Differentials: •Scrotal Pearls •Extratesticular calcified bodies within the scrotum •No clinical significance •Result from inflammation of tunica vaginalis or torsion of appendix testis •Large-Cell Calcifying Sertoli Cell Tumor •Gonadal stromal tumor •Bilateral, multifocal •Most common cause of intra-testicular mascrolithiasis (mass may be almost completely calcified) •Testicular Granuloma •TB epididymo-orchitis may produce intrascroal calcifications

Testicular veins, right and left, names, where they drain into, ...

Veins: •The veins draining the testis exit at the mediastinum •Drained through pampiniform plexus •Veins that drain testis & then become the spermatic (testicular) veins •Right testicular vein •Drains into IVC •Left testicular vein Drains into Left Renal vein

Embryonal cell carcinoma & its sonographic appearance

•A malignant new growth made up of epithelial cells tending to infiltrate surrounding tissues and to give rise to metastases •A form of cancer, that makes up the majority of the cases of malignancy of the breast, uterus, intestinal tract, skin, and tongue •Embryonal carcinoma is a relatively uncommon type of germ cell tumor that occurs in the ovaries and testes • Accounts for approximately ten percent of testicular germ cell tumors average age at diagnosis is 31 years Clinically: •Embryonal carcinomas are aggressive germ cell tumors •The peak incidence occurs in persons of about age 30 years. •About 10-40% of patients (including those with pure and mixed forms) present with metastasis •the more common sites of metastasis are the retroperitoneum, lung, and liver Sonographic Findings: •Heterogeneous •Predominantly solid •Mixed echogenicity •Poorly marginated •Coarse calcifications (infrequent) •May invade tunica albuginea & distort testicular contour

Leydig cell tumor & its sonographic appearance

•A type of testicular cancer affecting the stromal cells of the testis •structural and hormone-producing cells of the testis •Stromal cells are connective tissue cells of any organ, for example in the uterine mucosa (endometrium), prostate, bone marrow, and the ovary •They are cells that support the function of the parenchymal cells of that organ •Fibroblasts and pericytes are among the most common types of stromal cells •Decreased libido, gynecomastia, impotence •Painless testicular enlargement •3% of all testicular tumors •90% benign •3% bilateral May produce testosterone Sonographic Findings: •Small solid hypoechoic intratesticular mass •Larger tumors: hemorrhage or necrosis leads to heterogeneous echo pattern •May occasionally show cystic changes

Zones of the prostate (anatomical location)

•Anatomically divided into several parts •Base •The most superior 1 cm portion of the gland •Lies against & continuous with bladder neck •Urethra enters base •Anterior to the base of the prostate is the symphysis pubis •Apex •The most inferior 0.5 cm portion of the gland •Lies inferior to the upper (superior) surface of the urogenital diaphragm •Urethra leaves the prostate just above the apex on the anterior surface •The space b/n the base & apex is the mid-gland

Appendix testes

•Appendix testis (hydatid of Morgagni) •An anomaly of the testes •Remnant of paramesonephric duct in males (mullerian duct) •Degenerates except for small portion at its cranial end •Rare, but can become torsed •1/3 of patients present with a palpable "blue dot" discoloration on the scrotum •This is nearly diagnostic of this condition

Anatomical location of the apex & base of the prostate

•Base •Lies against & continuous with bladder neck •Urethra enters base •Apex •Lies inferior on the upper surface of the urogenital diaphragm •Urethra leaves the prostate just above the apex on the anterior surface The apex of the prostate gland is located at the bottom of the gland. The apex is pointed down to the perineum as opposed to the base which is wider and located next to the bladder. Its base sits at the neck of the urinary bladder, surrounding the proximal portion of the urethra. The urethra courses through the gland (known here as the prostatic urethra) and exits inferiorly at the apex.

BPH

•Benign Prostatic Hyperplasia (BPH) •Increased number of cells •Aka: Benign Prostatic Hypertrophy •Hyperplasia of the periurethral gland •Usually originating in the transitional zone •Common in males over 50 Sonographic Appearance •Enlargement of the anterior/inner gland is typical •May significantly compress peripheral zone •Echogenicity varies with tissue composition and tissue changes that accompany hyperplasia •Normally hypoechoic to peripheral zone •More fibrous components increase echogenicity •Calcifications •Hypoechoic nodules that may mimic tumors Treatment of BPH •If symptomatic (BPH, ARU (acute urinary retention)), •Medication •Surgical excision of inner gland leaving the peripheral outer gland intact •Several surgical approaches (ex. TURP), also cryosurgery or microwave destruction •On patients who have had prostate resection, a dilated urine filled prostatic urethra may be seen on ultrasound

Epididymitis & its sonographic appearance

•Epididymitis happens when the epididymis becomes infected or inflamed •It's often the result of a sexually transmitted infection (STI) (chlamydia or gonorrhea) and UTI Symptoms: •Scrotal or testicular pain or tenderness •Tenderness on transducer pressure •Warmness or redness in the scrotum •Unusual fluid coming out from the penis •Frequent or painful urination •Bloody semen, pyuria, dysuria, erythema •Fever •Depending on the type of infection, one may need to take antibiotics or antiviral medications Differentials: •Malignant testicular tumor •intratesticular masses, especially if they are palpable, are likely to be malignant and must be surgically explored •Testicular torsion •Blood flow is minimal or absent Sonographic Findings: •Isoechoic or slightly hypoechoic structure with medium-level echoes & enlarged •Increased blood flow in the epididymis •Usually, the body of the epididymis is not identified at sonography in healthy adults •Sometimes, the epididymal tail is seen

Transitional Zone

5% of prostatic glandular tissue Seen as two small glandular areas located adjacent to the proximal urethral segment Ducts of the transition zone end in proximal urethra at the level of verumontanum Benign prostatic hyperplasia (BPH) usually originates in this zone 10% - 20% of malignancy occurrences

Relational anatomy of the prostate (base & apex)

Anterior (base of prostate) Symphysis pubis Abdominal wall Urethra enters near anterior wall Inferior (apex of prostate) Perineum Urogenital diaphragm

Zones of the prostate (occurrence of BPH, occurrence of cancer, diagram, ...)

BPH, or Benign prostate Hypertrophy/Hyperplasia, mostly originates from the transitional zone. BPH can occur in the central zone, but it originates in the transitional zone.

Central Zone

Central zone: Pyramidal-shaped at base of prostate Extends from base to where it narrows at the verumontanum (entrance of seminal vesicle) Located at the base of the prostate 25% of gland 5% - 10% of malignancy Invaginated extraprostatic space Inward extension of extraprostatic space composed of loose connective tissue Site where seminal vesicles and/or ejaculatory ducts enter the central zone This space is devoid of prostatic capsule & is a potential route of spread of tumor outside Terminate in the proximal urethra near the verumontanum .... (where the ejaculatory ducts join the urethra)

All most commons

Hydrocele-Most common cause of painless scrotal swelling Hydroceles are most common in babies. Epididymitis is the most common cause of ACUTE SCROTAL PAIN in adolescent boys and adults. Mumps is the most common virus that causes orchitis. It most often occurs in boys after puberty. Large-Cell Calcifying Sertoli Cell Tumor Most common cause of intra-testicular mascrolithiasis (mass may be almost completely calcified) Germ cell tumors are by far the most common testicular tumors Seminoma - most common carcinoma/germ cell tumor Embryonal carcinoma is one of the most common germ cell tumors. Leydig- most common form of gonadal stromal tumors also called non-germ cell, interstitial cell, or sex cord tumors Fibroblasts and pericytes are among the most common types of stromal cells VARICOCELES Most common cause of infertility in men Testosterone is the most common form of androgen. The most common presentation of pure teratomas is a painless testicular mass The most common sites of metastasis in testicular cancer are the lymph nodes in the lungs and abdomen Testicular Torsion-Most common between ages 12 and 18, but it can occur at any age, even before birth Simple cysts- Located anywhere but most common in mediastinum testis Epidermoid Cysts- Can appear anywhere on the skin, but are most common on the face, neck, trunk, & scrotum

The main function of the prostate and the testicles

Main Function of Prostate: •Secretes a milky, alkaline fluid that nourishes and protects sperm •Fluid helps: Nourish and protect the sperm during intercourse Forms the main bulk of ejaculate •During ejaculation, prostate squeezes this fluid into the urethra, and expel it with sperm as semen •The vasa deferentia (singular: vas deferens) bring sperm from the testes to the seminal vesicles •The seminal vesicles contribute fluid to semen during ejaculation •Singular: testis, commonly known as the testicles, are a pair of ovoid glandular organs that are central to the function of the male reproductive system •Responsible for the production of sperm cells and the male sex hormone testosterone •Produce as many as 12 trillion sperm in a male's lifetime, about 400 million of which are released in a single ejaculation •Paired oval glands •Function: •Exocrine gland (Produces spermatozoa) •Endocrine gland (Synthesizes and secretes testosterone (male sex hormone)

Mediastinum testes and its sonographic appearance

Mediastinum teste Thickened portion of albuginea along the posterior border of the testis Sonographic Appearance Highly echogenic Linear structure peripherally located in posterior-superior aspect to testis

Peripheral Zone

Posterior, lateral, apical gland Surrounds distal urethral segment Separated from transitional zone & central zone by capsule 70% of prostate tissue 70% of malignancies

Seminiferous tubules

Produce sperm (spermatogenesis) •Sperm moves through seminiferous tubules to the straight tubules - leads to rete testis Rete testis (Tubular Ectasia/Rete Testis): formed by seminiferous tubules Normal variant of dilated seminiferous tubules in mediastinum testis

Rete testis & how it is formed

Rete testis: Formed by seminiferous tubules Located at mediastinum Drain from testes into efferent ducts, which drain into tubules that form the epididymal head

Five main pathways of the sperm

Testis - Epididymis - Vas Deference - Ejaculatory Duct - Urethra

Undescended testicles and the risk

Typically, every male is born with two testicles. They form in the abdomen, and drop into the scrotum during their seventh month of gestation. Sometimes, though, the testicles do not drop, and the baby is born with a condition called undescended testicles. This happens for about 2 percent of males, and in 10 percent of those cases, both testicles are not in their proper position. Typically, this is a problem associated with preemies and the testicles often "drop" within a few months. If not, surgery may be required. Once testicles have dropped, they may not stay there. Retractile testicle is when a testicle moves into the groin area. Usually, a doctor can move the testicle back into its proper position, but if it is stuck, it is called an ascending testicle or an acquired undescended testicle. In this case, surgery may be needed to move it into proper position and stitch it into place. Ultrasound used to scan groin and abdomen to locate testicle Sonographically appear smaller and hypoechoic in comparison to normal testicle •Most of the time, children's testicles descend by the time they are 9 months old •Undescended testicles are fairly common in infants who are born premature •An undescended testicle is more likely to develop cancer, even if it is brought down into the scrotum. •There are usually no symptoms, except that the testicle cannot be found in the scrotum (this may be described as an empty scrotum). •Surgery (orchiopexy) to bring the testicle into the scrotum is the main treatment. Having surgery early may prevent damage to the testicles that can cause infertility.

Epidermoid cyst and its sonographic appearance

•A cyst of the epididymis containing serous liquid •Difficult to differentiate from a spermatocele except by aspiration, since a spermatocele contains milky-appearing sperm • May be anywhere in epididymis •Lined with epithelium & contains clear serous fluid & likely to be lymphatic origin •Testicular epidermoid cysts, also known as keratocysts, are rare benign tumors •Can appear anywhere on the skin, but are most common on the face, neck, trunk, & scrotum •Often painless, so they rarely cause problems or need treatment Sonographic Findings: •"target/bull's eye" pattern (due to echogenic center) •Confined to tunica albuginea •Sharply circumscribed encapsulated mass •"Onion-skin" appearance due to alternating hypo/hyperechoic rings

Spermatocele & its sonographic appearance

•A spermatocele (or spermatic cyst) is a fluid-filled sac that grows in the head of the epididymis •That's a small tube near the upper testicle that collects and transports sperm •Happen when sperm pools in the epididymis •Cause unknown •Often develops for no specific reason at all •Contains: •A thick milky fluid •Spermatozoa, lymphocytes, & cellular debris Sonographic Findings: •Well-defined •Anechoic/hypoechoic •Head of epididymis •Posterior acoustic enhancement •Low-level echoes •Spermatocele usually displaces testis anteriorly

Hydrocele

•Excess fluid builds up in the cavities (tunica vaginalis) around one of the testicles •Scrotal fluid surrounding testis, except for "bare area" where tunica vaginalis does not cover testis & is attached to epididymis •Normally, there is a small amount of fluid that surrounds the testis •Sometimes present at birth, but it can also result from an injury or inflammation •Most common cause of painless scrotal swelling Hydrocele symptoms: •scrotal swelling that gets more noticeable as the day goes on •dull ache in the scrotum •feeling of heaviness in the scrotum •Hydrocele usually doesn't require treatment unless they are very large or cause pain • Most go away on their own, but more severe cases might require surgical repair Types: •Congenital •Infantile •Primary •Secondary •Occurs if the channel through which the testicles descend hadn't closed all the way and fluid now enters or the channel reopens •Cause fluid to move from the abdomen into the scrotum •Can also be caused by inflammation or injury in the scrotum or along the channel •The inflammation may be caused by an infection (epididymitis) or another condition Sonographic finding: Acute: anechoic fluid collection surrounding anterolateral aspect of testis •Usually testis is displaced posteromedially Chronic: low-level, mobile echoes •Cholesterol crystals presumed to cause these low-level mobile echoes & cannot be distinguished from inflammatory debris •Diffuse scrotal wall thickening, parietal calcifications, & scrotoliths •Septations are infrequent & mostly due to secondary trauma or infection

Endocrine & exocrine function of the testes

•Function: •Exocrine gland (Produces spermatozoa) •Endocrine gland (Synthesizes and secretes testosterone (male sex hormone)

Orchitis & its sonographic appearance

•Inflammation of the testicle due to trauma, tumor, or infection •Primary orchitis: isolated orchitis (may be seen in boys with mumps) •Orchitis usually develops 4 - 6 days after the mumps begins •Because of childhood vaccinations, mumps is now rare in the United States •Secondary: infection spread from adjacent organs •Infections of the prostate or epididymis •Acute/chronic orchitis or epidiymo-orchitis Labs: •Complete blood count (CBC) •Tests to screen for chlamydia and gonorrhea (urethral smear) •Urinalysis •Urine culture (clean catch) - may need several samples, including initial stream, midstream, and after prostate massage Sonographic Findings: •Testicle may be normal or enlarged •Focal areas of decreased echoes unless chronic •Hyperemia evident with color flow •Cannot be differentiated from tumors when initially found •May form abscesses •Differentials same as epididymitis

Testicular arteries, right and left, names, where they originate from, ...

•Three primary arteries supply the scrotal structures: 1. Testicular artery - arising from the aorta and supplies the testis 2. Cremasteric artery - a branch of the internal epigastric (internal iliac) artery and supplies the scrotal sac and coverings of the spermatic cord 3. Deferential artery - arising from the superior vesical artery and supplies the vas deferens and epididymis

Cowper's gland (bulbourethral gland), anatomical location

•Two small pea-sized exocrine gland •Located behind and lateral to urethra at the base of the penis •Function: •Releases a fluid to lubricate urethra to allow sperm to pass through (prior to ejaculation) •Helps flush out any residual urine or foreign matter & Reduces the acidity of the urethra