Male Pelvis: Prostate Gland

Ejaculatory duct

(vas deferenses) The seminal vesicles join the vas deferens to form the ejaculatory duct, which passes through the central zone.

Facts about prostatic cancer

70% of prostatic cancers originate in the peripheral zone. It is anechoic to hepoechoic in the early stage. Associated factors include benign prostatic hepreplasia and hormonal influence. Clinical presentation may include urinary obstruction.

Location of malignant masses

70% originate in the peripheral zone 20% in the transitional zone 10% in the central zone.

Transurethral Resection of the Prostate (TURP)

A knife placed on the end of a cystoscope rotates, removing the prostate surrounding the cystoscope in an apple-coring fashion.

Anterior fribromuscular Stroma

A thick nonglandular sheath of tissue that covers the entire anterior surface of the prostate and it is a nonglandular region.

Neurovascular Bundle.

An echogenic mass composed of nerves, veins and arteries seen on the postero-lateral aspect of teh prostate on transverse images.

Benign prostatic hyperplasia and hypertrophy

Benign hyperplasia affects 80-90% of adult men.

Sonographic appearance of Prostetic cancer

Cancer is sonographically variable. It first appears as anechoic-hypoechoic then becomes isoechoic to hyperechoic as it spreads to the central gland.

Utricle

Cystic embryologic remnant in the midline within the prostate.

symptoms

Decrease flow of urine, difficult urinating (initiating and stop urinating) nocturia, and urinary retention.

Denonvilliers' fascia

Denonvillers' fascia is located posterior to and separates the prostate from the rectum

An endorectal examination of the prostate should begin with:

Digital rectal examination. This examination should be done before probe is inserted.

Hydrocele

Distention of the sac that encloses the tescticle with straw-colored fluid.

Sonographic characteristics of prostatic cancer may commonly include all of the following:

Early prostetic cancers can present as anechoic or hypoechoic lesions in the peripheral zone. they can break through the prostatic capsule causing distortion or they can invade the seminal vesicles.

Pampiniform Plexus

Group of veins that drain the testicles. They dilate and become tortuous when a varicocele is present.

Etiology:

Hormonal factors

What can mimic intraprostatic cancer?

Hyperplastic nodules, cysts, infarcts, inflammation, blood vessels and muscle tissue can simulate prostate cancer.

Apex

Inferior region of the prostate

Prostatitis

Inflamation of the prostate gland, may initiate in any area of the gland.

Facts about benign hyperplasia

It occurs mostly in the transitional zone, and nodules occasionally develop in the periurethral glandular tissue. It affects 80-90% of men and its incidence increases with age.

mediastinum testis

Linear fibrous structure in the center of the testicle

Central zone

Located at the base of the gland. (10% of cancers originates int he central zone) Portion of the prostrate that surrounds the urethra. Site of benign prostatic hypertrophy.

Transitional zone:

Located in the central region on both sides of the proximal urethra. (20% of cancers originate here)

Anterior fibromuscular stroma

Nonglandular region that forms the anterior surface of the prostate.

Epididymis

Organ that lies posterior to the testicle in which the spermatozoa accumulates.

Appendix epididymis

Portion of the epididymis that lies just superior to the testicle and is larger than remainder of the epididymis.

Elevated prostatic-specific antigen may indicate

Prostatic cancer

Prostatic Carcinoma

Second leading cause of death among american men. ethiology: Age, genetic or racial makeup, hormones, dietary fat, infectious agents.

Seminal vesicles

Seminal vesicles are located on the posterior-superior surface of the prostate.

TNM

Staging technique for prostate cancer T= tumor, N= nodes, M= metastasis

Base

Superior region of the prostate

Vas deferens

The duct linking the testicles and epididymis with the urethra.

Urethera

The ejaculatory duct empties into the urethra at the verumontanum.

Prostate function

The function of prostate is the secretion of alkaline fluid. The prostate discharges this fluid into the urethra to enhance the motility of sperm.

Sonographic features of acute prostatitis

The gland may be surrounded by a hypoechoic rim, have an echo-free halo around the periuretrhal zone, or have scattered low-level echoes within the gland.

Normal adult prostate weights and measures aprox

The normal postpubescent prostate weights about 20gr and measures 5x8x4

Prostate capsule

The normal prostate capsule is smooth, well defined and highly echogenic

The seminal vesicles

The seminal vesicles are joined by the vas deferense, they are normally less echoic than the prostate and they are different in size.

Peripheral zone

This zone consists of the posterior, lateral and apical parts of the prostate extending anteriorly. 70% of prostate cancers originate here. Initial stages of prostatitis generally start in peripheral zone.

Anatomic description of the prostate gland

Three glandular zones: transitional, central and peripheral zones with one nonglandular region called anterior fibromuscular stroma. apex is located inferiorly, the urethra runs through the gland

Oblitaration of the nipple and prostate-seminal vesicle angle may indicate:

Tumor infiltration. The tumor will oblitarate the "nipple" and prostate-seminal vesicle angle.

Tumor invasion

Tumor invasion does not commonly affect the characteristics of the doppler waveform in the seminal vesicles.

Urethra

Urine is drained from the bladder via this tube that passes through the center of the gland

Verumontanum

Verimontanum is a midpoint region between the base and the apex of the prostate.

Prostatitis etiology

acute or chronic bacterial infections or of unknown nonbacterial factors.

Prostatitis sonographic appearance

acute: hypoechoic rim surrounding the gland. echo free halo surrounding the periurethral zone and diffuse, low echogenic areas within the gland. chronic: diffuse inhomogeneous echogenicity and fluid-filled areas within the prostate.

sonographic appearance of prostatic cysts

anechoic cysts with sharp walls and demonstrate good sound transmission.

Diagnostic criteria for neoplasms invading seminal vesicles inlcude:

asymmetry in the size, shape and echogenicity of the vesicles. The doppler waveform is not affected by the invasion of tumors in the vessicles.

Clinical symptoms

back pain, obstruction of urinary outflow.

Hematocele

blood filling the sac that surrounds the testicle

The prostate is bounded anteriorly by

bounded anteriorly by vessels, fat, lymphatics, nerves and fascial tissues, collectively termed the anterior prostatic fat and fascia.

Ejaculatory ducts

connect the seminal vesicle and vas deferens to the urethra at the verumontanum.

Corpora Amylacea

corpora amylacea is Calcification within the central zone of the prostate. Degererated epithelial cells of the prostate are shed and become suspended in albuminous fluid. calculi are formed by the consolidation of corpora amylacea.

Clinical Symptoms of prostatitis

fever, pelvic and low back pain, urinary frequency and urgency and dysuria.

Prostatic cysts

frequently congenital and secondary to obstruction of the semnal vesicle and ejaculatory duct. differential diagnosis includes cyst in the mullerian duct and diverticula of the ejaculatoru duct.

The transitional zone

is located on both sides of the proximal urethra and represents 5% of the gland. it is also the primary site of benign prostatic hyperplasia.

Location of benign hyperplasia

originates in the transitional zone and periurethral glandular tissue

An echo-free halo around the periurethral zone may indicate:

prostatitis

Prostate specific antigen (PSA)

protein derived only from prostate elevated in prostate cancer, hypertrophy and prostatitis.

sextant biopsy

six biopsies taken from the right and left upper, middle, and lower peripheral zones.

The central zone:

the central zone is a triangular structure located at the base of the prostate with its apex at the veromountanum.