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.