Penis and Prostate

How many cylindrical structures is the penis composed of?

3

What is the corpora cavernosa?

Two structures that make up the dorsal aspect of the penis

What is the corpus spongiosum?

One structure that makes up the ventral aspect of the penis

What are the corpora cavernosa and corpus spongiosum composed of?

Sinusoidal spaces

What are the functions of the sinusoidal spaces?

The spaces in corpora cavernosa fill with blood during erection

What are the corpora cavernosum and the corpus spongiosum covered by?

Tunica albuginea

What is the tunica albuginea?

Thick fascial shealth covering the corpora cavernosum and corpus spongiosum

What strong, deep penile layer is superficial to the tunica albuginea?

Buck’s fascia

Where is the root of the penis attached to?

Interior fascia of urogenital diaphragm

What passes through the center of the corpus spongiosum?

Penile urethra

What is the posterior urethra composed of?

1. Prostatic

2. Membranous

What is the anterior urethra composed of?

1. Bulbous urethra

2. Penile urethra

What is the normal urethra lumen diameter?

4 mm or less

What is the distal part of the penis, that exhibits a conical shape?

Glans penis

What is the glans penis formed by?

An expansion of the corpus spongiosum

What are the bulbourethral glands?

Two exocrine glands

Where are the bulbourethral glands located?

1. Posterior and lateral in membranous urethra

2. Imbedded in muscle of urogenital diaphragm

Where are the ducts of the bulbourethral glands located?

1. Pierce perineal membrane

2. Terminate in spongy urethra

What is the function of the bulbourethral glands?

1. Produce clear mucus during sexual excitation for lubrication of

   1. Glans

   2. Urethral meatus (orifice)

What arteries supply blood to the penis?

1. Common iliac arteries

2. Internal pudendal arteries

Where do the left and right penile arteries enter? What do they branch into?

1. Enter at base of penis and branch into

   1. Cavernosal (deep) artery

   2. Dorsal penile artery

   3. Bulbourethral artery

What does the cavernosal (deep) artery supply?

Corpora cavernosa

What does the dorsal penile artery supply?

Corpus spongiosum

What does the bulbourethral artery supply?

1. Urethral bulb

2. Corpus spongiosum

What provides the primary source of blood flow to the erectile tissue of the penis?

Cavernosal arteries

What does the dorsal artery branch into?

Circumflex arteries

What are the circumflex arteries? Where are they located?

1. Anastomotic branches

2. Between

   1. Dorsal penile artery

   2. Deep cavernosal arteries

What is the venous blood flow path of the erectile tissue of the penis?

1. Emissary veins

2. Circumflex veins

3. Deep dorsal penile vein

4. Retropubic (periprostatic) venous plexus

What is the venous blood flow path to drain the corpus cavernosa?

1. Cavernosal veins

2. Internal pudendal veins

What is the venous blood flow path to drain the skin and glans of the penis?

1. Superficial dorsal veins

2. Saphenous veins

What occurs during an erection?

1. Smooth muscle relaxation

2. Sinusodial spaces have increased arterial inflow

3. Sinusodial spaces have limited venous outflow

What occurs so that during an erection the sinusodial spaces have limited venous outflow?

Compression of emissary veins

What are the indications for a penile ultrasound?

1. Masses

2. Trauma

3. Urethral strictures

4. Impotence (vasculogenic impotence)

5. Peyronie’s disease

6. Congenital anomalies

How do we perform a penile ultrasound?

1. Penis lying on anterior abdominal wall, ventral side up

2. Copious amounts of gel

3. Gentle compression

What frequency transducer is to be used during a penile ultrasound?

1. High frequency

2. 7.5-10 MHz

How are the corpora cavernosa seen in transverse?

Two circular structures separated by the septum penis

What portion of the corpora cavernosa are the cavernosal arteries seen in?

Middle

Are the deep dorsal penile arteries or the cavernosal arteries larger when being compared on an ultrasound?

Cavernosal arteries

How are the fascial regions such as the tunica albuginea seen on an ultrasound?

Hyperechoic

What is important to note when scanning palpable abnormalities?

1. Assess sonographic features

2. Pinpoint exact location in relation to corporal bodies

What is erectile dysfunction or impotence?

The inability to attain or maintain an erection

What is the most common cause of erectile dysfunction or impotence?

Vasculogenic conditions or impotence

What can vasculogenic conditions or impotence be caused by?

1. Poor arterial flow due to atherosclerosis or diabetes

2. Excessive venous leakage

What is an angiography?

1. Invasive procedure

2. Gold standard for evaluation of arteriogenic impotence

What does a penile-brachail index (PBI) evaluate for?

Arteriogenic impotence

What is a penile-brachail index (PBI)?

1. Non-invasive procedure

2. Performed by placing blood pressure cuffs
   on upper arms and shaft of penis and obtaining
   systolic blood pressures

How is a penile-brachail index (PBI) calculated?

Systolic penile artery pressure / Systolic brachial artery pressure

What are the values for a PBI?

1. Normal = 0.7-1

2. Borderline abnormal = 0.6-0.7

3. Abnormal = Below 0.6

How is a Doppler ultrasound performed to check for erectile dysfunction?

1. Vasodilating drug is injected into penis

2. Causes erection

3. Arterial blood supply is evaluated using Doppler

What is Peyronie’s Disease?

Fibrosis of fibrous sheaths covering corpora cavernosa that affects men 45 and older

What direction does the erected penis bend if someone has Peyronie’s Disease?

ALWAYS bends TOWARD diseased or affected area

What is chordee? When does this occur?

The bending of the erected penis towards the infected area in someone with Peyronie’s Disease

A man comes in to receive an ultrasound. It shows dense, hyperechoic areas near the peripheral margin of the corpus cavernosa, along the dorsal aspect of
the penis. What condition does he have?

Peyronie’s Disease

What do almost all tumors of the penis originate from? What part of the penis do they almost always involve?

1. Epithelial origin

2. Distal portion of penis

Does circumcision increase or decrease someones risk of developing carcinoma?

Penile carcinoma is less where circumcision is common

What percentage of patients are likely to have penile carcinoma metastases in the inguinal lymph nodes?

50%

What are the four stages of penile carcinoma?

1. Stage 1: Carcinoma involves a lesion limited to glans and foreskin

2. Stage 2: Tumors invade shaft or corpora cavernosa

3. Stage 3: Tumors invade shaft and lymph nodes

4. Stage 4: Tumors have distant metastases

A man comes in to receive an ultrasound. It shows a mass within the penis with well defined margins and involvement of corporal tissues. FNA is needed to aid in diagnosis. What condition does he have?

Penile carcinoma

How is penile trauma classified?

1. Penetrating: knife, bullet

2. Blunt

When is the most common time that penile trauma occurs?

When the penis is erect

What is the most common form of penile trauma?

Penile fracture

What direction does the erected penis bend if someone has a penile fracture?

AWAY from affected area

When does a penile fracture occur? What is this often associated with?

1. Occurs when there is disruption of tunica albuginea and corpora cavernosa

2. Often associated with urethral tear

What is the eggplant deformity?

1. Extravasation of blood under Buck’s fascia

2. Results in unilateral asymmetrical fluid collection

A man comes in to receive an ultrasound. It shows an extravasation of blood under Buck’s fascia resulting in unilateral asymmetrical fluid collection. The tunica albuginea is hypoechoic with a break in the banding. What condition does he have?

1. Penile rupture or vascular trauma

2. Penile trauma

What is a priapism?

When an erect penis does not return to flaccid state, despite absence of stimulation

What is a superficial dorsal penile vein thrombosis? What happens soon after this occurs?

1. A cord or string-like blood clot in superficial dorsal vein of penis

2. Spontaneous reopening of vein and symptoms often disappear completely

A man presents with inflammation, pain, and fever. He also has a palpable cord-like lesion that appeared after prolonged sexual intercourse. The ultrasound shows thrombosis and a diseased segment of the superficial dorsal vein. Color Doppler shows an abscence of flow. What condition does he have?

Acute superficial dorsal penile vein thrombosis

A man presents with minimal pain and chronic swelling in the coronary sulcus. He also has a palpable cord-like lesion that appeared after prolonged sexual intercourse. The ultrasound shows thrombosis and a diseased segment of the superficial dorsal vein. Color Doppler shows an abscence of flow. What condition does he have?

Subacute superficial dorsal penile vein thrombosis

When is echogenic foci seen within the penis?

1. Sinusoidal disease (calcification)

2. Peyronie’s disease

3. Penile fibrosis

4. Arterial calcifications (vascular disease)

5. Fatty tumors (lipoma, lipofibroma)

6. Fibrous tumors

7. Ulcerated penile carcinoma

What are the indications for an ultrasound of the urethra?

1. Urethral foreign body

2. Evaluation of urethral strictures

3. Detection of stone particles

4. Urethral trauma

5. Urethral diverticula

What is the preferred method for visualization of the urethra? Why?

1. Retrograde urethral filling method

2. Optimal distension maintained over a longer period of time

How is the retrograde urethral filling method performed?

1. Inserting a tapered tip syringe containing viscous lidocaine jelly into urethral meatus

2. Applying distal penile clamp to maintain distension of penile urethra

What is a urethral stricture?

1. Irregular narrowing of urethral lumen

2. Thickening of urethral wall

What is urethral stricture caused by?

Fibrosis and scarring following a previous inflammatory process or infectious disease

What is urethral stricture most commonly secondary to?

1. Gonococcal urethritis (gonorrhea)

2. Trauma

Where do most urethral strictures occur?

Anterior urethra

A man comes in to receive an ultrasound. It shows a focal area of narrowing within the urethra. What condition does he have?

Urethral stricture

What is a urethral diverticula?

Outpouching of urethra

A man comes in to receive an ultrasound. It shows a fluid-filled outpouching adjacent to the urethra. What condition does he have?

Urethral diverticula

How is a urethral foreign body ultrasound performed?

Bulbous and penile urethra should be scanned before
distension of urethra to locate foreign object
as it may be dislodged during retrograde filling

What is the funnel shaped, glandular structure surround by a fibrous capsule?

Prostate

What gland surrounds the male urethra?

Prostate

What is the base of the prostate?

1. Cephalic portion

2. Continuous with bladder neck

What is the apex of the prostate?

1. Caudal portion

2. Adherent to urogenital diaphragm

What three luminal structures transverse the prostate gland?

1. Right ejaculatory duct

2. Left ejaculatory duct

3. Urethra

What is the verumontanum?

Longitudinal ridge on posterior wall of prostatic urethra

What is the utricle?

Glandular opening at crest of verumontanum

What accounts for the Eiffel Tower appearance on transverse images of the prostate?

Utricle

Where is the prostate capsule located? What is it formed by?

1. At apex of prostate formed by

   1. Rectourethral muscle

   2. Rectum

   3. Urethra

   4. Prostate gland

What area has a potential weakness and is a site of extraprostatic spread of cancer?

Prostate capsule

What separates the prostate into anterior fibromuscular and posterior glandular portions?

Urethra

How much of the prostate does the fibromuscular portion make up?

1/3

How much of the prostate does the glandular portion make up?

2/3

What portion of the prostate contains four zones?

Glandular

What prostate zone constitutes 70% of the glandular tissue?

Peripheral zone

What prostate zone is located along the posterior, lateral, and apical portion of the gland?

Peripheral zone

Where do the peripheral zone ducts drain into?

Distal segment of urethra between verumontanum and apex

What is the most common location for carcinoma (about 70% of prostate cancers) and prostatitis?

Peripheral zone

What prostate zone constitutes 25% of the glandular tissue?

Central Zone