Scrotum- Part 1 Flashcards
Testicular Development
Testicles arise in fetal abdomen near kidneys. 4th month descend to level of bladder & remain there until 7th month. They descend through inguinal canal to scrotum after 7th month. Descent is controlled by hormones.
Process vaginalis
Evagination of peritoneum travels through inguinal canal from abdomen into scrotum
Scrotum
Pouch of skin that is continuous with abdomen. Suspended from base of male pelvis btw perineum & penis. Derived from labioscrotal folds.
Median Raphe: point of fusion of twin sacs
Scrotum Purpose & Contents
Protective casing. Maintain testicular temp at ~2 deg C below intrabdominal temp.
Contents: testicles, epididymis, proximal part of vas deferens
Testicles (testes)
Male gonads. Oval shaped symmetric. US: appear as smooth medium gray structures with fine echo texture.
Each testis: divided into ~250-400 lobules that contain SEMINIFEROUS TUBULES. Tubules join to from 20-30 larger ducts, known as the tubuli recti.
Testicle Size
Normally measure 3-5 cm in length. AP: 3cm. Width 2-4 cm. size & weight decrease with age.
Jobs of the scrotum:
Produces sperm & testosterone. 95% of testosterone is secreted by Leydig cells in the testicles.
Endocrine & exocrine functions: testosterone - endocrine
Tunica Albuginea
Echogenic, dense fibrous capsule surrounding testes. Covered b tunica vaginalis. Mult septa are formed from tunica Albuginea and coverage at mediastinum testis. Form lobules in the testes.
Mediastinum Testis
Posterior portion of tunica Albuginea reflects into the testis forming a vertical septum. Supports the testicular vessels and ducts. Extends into testicles from the epididymis.
Tunica Vaginalis
Serous membrane, formed by peritoneum, that partially testicle. Inner visceral layer covers testis, epididymis, lower spermatic cord. Outer parietal layer lines wall of scrotal pouch. Small amount of fluid btw 2 layers is normal. Layers normally not seem on US.
Seminiferous Tubules
Contained within the testes. Converge at apex of each lobule and anastamose. Tubuli recti enter mediastinum to form Rete Testis in medistinum testis. Rete testis drains into the head of the epididymis through Efferent Ductules.
Epididymis
Single tightly wrapped tube, 6-7cm, begins superiority and courses posterolateral to testis. Composed of head body tail and appendix. Aids in sperm maturing as well as concentrates, stores and transports sperm.
Epididymal Head
AKA: globus major. Measures 10-12 mm diameter. Superior to upper pole of the testis. Larger portion of epididymis. Formed 10-15 efferent Ductules from Rete testis joining together
Epididymal Body
Bod is smaller then head. Posterolateral margin of testicle.
Epididymal Tail
AKA: globus minor. Slightly larger then bod. Inferior to testis
Appendix Epididymis
Appendix is small protuberance on head. Commonly seen when hydrocele present (excess fluid in scrotum)
Seminal Vesicles
Are convoluted pouch like structures that empty into the distal ductus deferens to form ejaculatory ducts. NOT in the scrotum but part of reproductive tract. Paired gland encapsulated by connective tissue. US: appear as low level echoes superior to the prostate.
Appendix testis & Appendix Epididymis
Not always seen, but are susceptible to torsion.
Scrotal Skin Thickness
Typically 2-8 mm. Thickens in presence of inflammation and other conditions.
Mediastinum Testis on US
Sometimes seen as Echogenic band going through the testicle. Echogenic line that runs from superior to inferior pole of testicle. Parallel to epididymis longitudinally.
Vas Deferens
Continuation of ductus epididymis. Thicker & less convoluted. Dilates at the terminal end near the seminal vesicles. Part of the spermatic cord
Spermatic Cord
Connects the abdomen and scrotum. Suspends the testis in the scrotum.
Functions: arterial supply. Venous drainage. Contains nerves, lymph nodes & vas deferens. Bound by fibrous sheath. Lies directly under skin.
Verumontanum
Junction of ejaculatory ducts and urethra
Vascular Supply
Blood flow supply from deferential cremasteric & testicular arteries. Testicular a’s descend from aorta to enter spermatic cord. Arise anteriorly just inferior to renal A. Travel through inguinal canal with spermatic cord. Capsular arteries (tunica vasculosa) branch over surface of testis.
Venous Drainage
Pampiniform plexus- exits from mediastinum testis into spermatic cord. Converge into 3 vessels: testicular, cremasteric, deferential. Right testicular drains directly into IVC. Left testicular drains into LRV.
Sonographic Appearance
Homogeneous texture. Echogenicity increase with age. Sag:3-5 cm AP: 3 cm TRV: 2-4 cm. weight ranges from 12.5-19.0 grams. Normal volume= 15-20 cc
Volume= (length X width X AP)
What should be imaged
Spermatic cord should be scanned from inguinal canal to scrotum. Epididymal head body & tail. Head is superior to upper pole of the testicle. Isoechoic to testicle. More coarse than testicle.
Hydrocele
Space btw the layers of the tunica vaginalis contains excess serous fluid. MOST COMMON CAUSE OF PAINLESS SWELLING. Simple- anechoic. Reactive Hydroceles- contain echoes in fluid, caused by trauma infection. Epididymis attaches to testicular wall posteriorly, fluid only in anterolateral portion only.
Hematocele
Less common then Hydroceles. From surgery trauma diabetes torsion neoplasms. May contain septations. Wall of scrotum becomes thickened. PYOCELES- abscesses that rupture.
Cryptorchidism
Normal variant. Testicles fail to descend into scrotum. Can be due to short spermatic cord, fibrosis & adhesions, narrow inguinal canal. Can be found in abdomen, inguinal canal(65%), & external inguinal ring. Can cause infertility or cancer. Kids: orchiopexy. Adults: orchid tommy. Normal testicle is larger & more Echogenic than undescended one.
Polyorchidism
Also called supernumary testis- many testes. Can be found anywhere along path. Attach to normal testis b duplicated vas deferens. Function normally within scrotum.
Idiopathic Varicoceles
MOST COMMON CORRECTIBLE CAUSE OF INFERTILITY. 98% occur on the left side in ages 15-25. Dilated veins from obstruction of venous return. When patient “bears down” it lights up like a XMas tree.. You know!
Secondary Varicoceles
From extreme pressure on the spermatic vein, enlarged liver, abdominal masses or retroperitoneal mass compressing veins. Pt position doesn’t affect. Numerous anechoic structures. Measure more the. 2mm. Follow spermatic cord to inguinal canal. Can be compressed by probe.
Microlithiasis
Scattered tiny punctate foci throughout the testicle. May be unilateral or bilateral. Found to have significant association With testicular cancer
Hernia
Are from inguinal hernias that slip into the scrotum. 2types: Direct- caused by weakening of the floor. Indirect- when intestines escape into the scrotum. EXCESSIVE STRAINING OR LIFTING HEAVY THINGS COMMON CAUSES. Symptoms: scrotal swelling, palpable firm area within the scrotum, lower abd pain.
US of hernias
Scrotal mass with both Echogenic & anechoic mass. PERISTATIC MOTION can be detected.
Hydroceles & hematoceles with fibrous septations may appear like fluid filled bowel loops. Inflamed spermatic cord also mimics hernia.
Epididymitis
Inflammation of the epididymis. MOST COMMON CAUSE OF ACUTE SCROTAL PAIN IN ADULTS. Most common cause is UTIinfection spread through spermatic cord. Others: mumps, syphilis, viruses, STDs. Unilateral mostly. May be focal or whole epididymis is involved.
US of Epididymitis
Thick enlarged epididymis decreased echoes in affected area. Thickening of scrotal skin. Reactive hydrocele. Doppler shows increased blood flow in the affected area. May be isolated to head or tail.
Epididymo-Orchitis
Infection of both epididymis & testicle. Epididymitis spreads to testic,e 20-40% of cases. Testis is enlarged. May have focal abnormality or be entirely affected. Scrotal wall thickening. May lead to abscess formation.
Fournier’s Gangrene
Uncommon type of gangrene affecting soft-tissue of genital organs. Stems for. Infection, UTI, urethral injury/stricture, trauma (piercing). TX: debridement of entire scrotum, and occasionally penis as well. Usually requiring major reconstructive surgery with skin grafts
Epididymal Cysts
Asymptomatic. Can develop throughout the epididymis
Spermatocele
MOST COMMON TYPE OF EPIDIDYMAL CYST. Retention cyst of the small tubes that hold sperm. May cause anterior or inferior displacement of the testicle. Single or mult. No symptoms until symptomatic then surgically corrected. Range from .2-9 cm in size.
Tunica Albuginea Cysts
Range from 2-5mm. Present as palpable lumps. Usually Asymptomatic . 50-60 YEAR OLD MALES. Cause is unknown.
Torsion
Most common in children & teenage boys, but can happen at any age. Occurs when remnant stalk of tunica vaginalis is twisted causing restrictin/obstruction of blood flow to testicle. Surgical emergency in acute phase. Arterial occlusion followed by ischemia.
Testicular Rupture
Must be diagnosed early. Blunt trauma is most common cause. 90%can be saved if surgery is performed within 72 hrs. Treatment: repair or removal. Severe scrotal pain & swelling. Focal areas of altered echogenicity. Contour of testicle is irregular. Color flow can be used to avoid mistaking complex hematoma for rupture.
Testicular Hematoma
Focal hematoma. From trauma.. Absence of flow
