Scrotal filariasis is a manifestation of filariasis and refers to scrotal involvement from parasitic nematodes of the superfamily filarioidea.
Known disease of the tropics and sub-tropics and a cause of morbidity in Asia, Africa and the Western Pacific regions 2.
Scrotal haematocoeles are collections of blood within the scrotal sac, but outside of the testicle.
A haematocele normally occurs following trauma to the scrotum, or on occasion following surgery. Some think that a varicocele is a risk factor for developing a haematocoele 4.
The scrotum and its content are subject to a number of infective processes including:
Scrotal pyocoeles are purulent fluid collections in the scrotal sac that generally occur in conjunction with epididymo-orchitis.
Scrotal pyocoeles are typically a complication of epididymo-orchitis and testicular abscess but can also occur following trauma or surgery. The purulent fl...
Scrotal scintigraphy is a radio-isotope examination of the scrotal contents, primarily in patients presenting with scrotal pain.
Although, ultrasound remains the mainstay of scrotal imaging, scintigraphy can be used where the diagnosis is unclear, since ultrasound appearances for s...
Scrotal tunica cysts are paratesticular cystic lesions. They include
tunica vaginalis cysts
tunica albuginea cysts
Typically seen as a simple appearing paratesticular cystic lesion not in the region of the epididymis.
Scrotoliths, also known as "scrotal pearls", are benign incidental extra testicular macro-calcifications within the scrotum. They frequently occupy the potential space of the tunica vaginalis or sinus of the epididymis. They are usually of no clinical significance 1-2.
The scrotum is a dual-chambered protuberance of skin and muscle that contains the testes, epididymides, and spermatic cord. It consists of two chambers separated by a septum It is an extension of the perineum, and is located between the penis and anus.
The scrotal wall is compos...
Segmental renal hypoplasia (also known as the Ask-Upmark kidney) is a type of renal hypoplasia. It is often found in young females with severe hypertension. The aetiology is unknown but has been postulated to be congenital or a sequelae of pyelonephritis. It is associated with severe juvenile hy...
Segmental testicular infarctions are uncommon testicular lesions that usually result from arterial embolisation or thrombosis (as opposed to testicular infarction from torsion, which may originate from venous occlusion).
The causes of a segmental testicular infarct include:
The seminal vesicles are paired accessory sex glands of the male reproductive system. The seminal vesicle produces over two-thirds of the ejaculate and is very high in fructose.
The seminal vesicle is actually a 10-15 cm long tubular structure but is coiled tightly so it only me...
Seminal vesicle cysts can be congenital or acquired.
It is the presence of cysts within the seminal vesicles since birth. It is seen rarely and occurs probably due to an obstruction at the junction of the seminal vesicle and ejaculatory duct. It is associated with many other urogeni...
Sertoli cell tumours of the testis are uncommon sex cord stromal tumours. They are less common than Leydig cell tumours of the testis.
May present in both paediatric and adult males, depending on the histologic subtype.
Testicular mass or firmness. May occ...
Sex cord stromal tumours of the testis are uncommon testicular neoplasms. Although ~90% of these tumours are benign, they cannot be differentiated from testicular malignancies on imaging, and are therefore usually discovered after orchiectomy.
Leydig cell tumour of the testis (most common, ~30%...
Sickle cell disease (SCD) is an autosomal recessive condition resulting in the formation of abnormal haemoglobin (a haemoglobinopathy), which manifests as multisystem ischaemia and infarction, as well as haemolytic anaemia.
There is no recognised gender predilection. The highest ...
Abdominal manifestations of sickle cell disease (SCD) are wide and can involve many organs.
For a general discussion, please refer to sickle cell disease.
splenic enlargement may occur transiently with the sequestration syndrome, where rapid pooling of blood occurs in th...
A sigmoid kidney is an uncommon variant of the horseshoe kidney. Whereas the typical horseshoe kidney is fused only at the lower poles, in a sigmoid kidney both the upper and the lower poles are fused 1.
Erectile dysfunction is the occassional or consistent inability of a male to attain and maintain a penile erection sufficient enough and for a suffcient duration so as to allow vaginal penetration.
Erectile dysfunction is multifactorial in etiology. In general erectile dysfunction increases wit...
Skene duct cyst is a retention cyst that forms secondary to inflammatory obstruction of the paraurethral ducts (Skene ducts) in females.
They are lined by stratified squamous epithelium due to their origin from the urogenital sinus.
Skene glands are female paraurethral glands that secrete mucus during sexual activity. They are homologous to the male prostate gland.
If the Skene duct becomes obstructed (inflammation, inspissated mucus), then a Skene duct cyst may result.
Small cell carcinomas of the bladder are rare bladder cancers with a poor prognosis. Its appearance overlaps other bladder cancers, in particular, urothelial/transitional cell carcinoma.
A very rare tumor, it has been estimated at <0.0001% of bladder cancers. It is thought to have...
The soft-tissue rim sign is used to distinguish a ureteric calculus from a phlebolith. The former appears as a calcific density with a surrounding rim of soft tissue which represents the oedematous ureteric wall. Phleboliths on the other hand usually have imperceptible walls (although up to 8% m...
Solitary filling defect with a ureter, as seen on conventional IVU or CT IVU has some differentials, including:
within the lumen
within the wall
transitional cell carcinoma (TCC)
When multiple fi...
SpaceOAR is a technique in which a physical space is created between the prostate gland and rectum for electron beam radiotherapy targeted to the prostate cancer.
OAR stands for "organ at risk", and in cases of prostate cancer radiotherapy treatment the rectum is the main organ at risk. The in...
The spaghetti sign refers to the presence of a linear worm like filling defect within a contrast opacified bladder. This linear filling defect is considered to represent blood clot extruded from the ureter and thereby moulded in the tubular shape. It is seen in patients with gross haematuria. Pr...
Sperm cell granuloma, also termed epididymitis nodosa, is a benign lesion that can occur in the scrotum. They can particularly occur in those with a prior vasectomy (occurs after vasectomy in up to 40% of patients 2).
It is considered a form of chronic epididymitis which occurs secon...
The spermatic cord is the tubular structure that suspends the testes and epididymis.
The spermatic cord starts at the deep inguinal ring, passes through the inguinal canal and exits at the superficial inguinal ring into the scrotum 3.
Handy mnemonics to recall the contents of the spermatic cord are:
Piles Don't Contribute To A Good Sex Life
Protection Doesn't Contribute To A Good Sex Life
3 arteries, 3 nerves, 3 other things
Piles Don't Contribute To A Good Sex Life
Protection Doesn't Contribute To A Good Sex L...
Spermatic cord hydrocele (SCH) refers to loculated fluid collection along the spermatic cord. It separated from and located above the testicle and the epididymis.
It results from aberrant closure of the processus vaginalis.
There are two recognised sub types
encysted hydrocele - fl...
Spermatic cord leiomyosarcomas are uncommon malignant paratesticular masses.
Accounts for ~10% of spermatic cord sarcomas. The average of a patient at presentation is 58 years old (although has been seen as young as 15 years old).
Patients may have left inguina...
Spermatocoeles are a common type of extra-testicular cyst, and represents cystic dilatation of tubules of the efferent ductules in the head of the epididymis.
Usually a painless, incidental finding but can present as a mass lesion if large 3.
Spigelian-cryptorchidism syndrome is the association of Spigelian hernias and cryptorchidism in children.
It is reported that ~50% (range 28-75%) range of paediatric patients with Spigelian hernias will have ipsilateral cryptorchidism 1,2.
Along with Spigelian hernia and cryptorch...
Spinning top urethra is non-obstructive posterior urethral dilatation seen on voiding cystourethrography, mainly in females. It was initially considered as an indicator of distal urethral narrowing/stenosis. However, it is now believed to be due to functional discoordinate voiding or bladder ins...
Splenogonadal fusion is a rare anomaly that occurs when there is congenital fusion between a portion of the spleen and a gonad or other mesonephric derivative.
Much more common in male patients (~95%), occurs most commonly on the left (98%) and usually involve the testis (95%). Ha...
The split bolus technique is a CT imaging investigation used in patients with haematuria aiming to put together, in a single image acquisition, both the nephrographic and renal excretory phases and thus reducing the radiation dose of the study. It is a CT protocol adopted for some institutions f...
A spoke wheel pattern in renal imaging refers to a vascular appearance seen with certain renal tumours, typically seen in oncocytomas but can also be seen in renal cell carcinomas.
This appearance refers to a peripheral rim of vessels from which centripetal vessels converge centrally giving th...
Spontaneous retroperitoneal haemorrhage (SRH) is a distinctive clinical pathology of retroperitoneal bleeding without a preceding history of trauma.
Clinical presentation may be vague and varied:
no inciting history
no evidence of cutaneous bruising
back, lower abdomin...
Spontaneous rupture of the renal pelvis (SRRP) is a rare complication that can occasionally occur with obstructive urolithiasis or occasionally infection 1. Leakage of urine can result in a urinoma.
A spotted nephrogram refers to non homogenous, irregular, patchy renal parenchymal enhancement seen predominantly on angiograms.
It is considered to be due to focal areas of cortical ischaemia or necrosis seen as a result of small vessel occlusion. This abnormal perfusion pattern can...
Squamous cell carcinoma of the urinary bladder is rare and accounts for only ~3-8% 1,2 of all bladder cancers (90% are transitional cell carcinomas) but nevertheless, SCC is the most common type of nontransitional cell carcinoma involving the bladder 2. SCC of the bladder is observed more freque...
Squamous cell carcinoma of the penis arises most commonly at the distal end of the penile urethra with local invasion of the glans.
In addition to TNM classification, the following staging is used:
stage I: confined to the glans or foreskin
stage II: invasion of penile shaft
Staghorn calculi, also sometimes called coral calculi, are renal calculi that obtain their characteristic shape by forming a cast of the renal pelvis and calyces, thus resembling the horns of a stag.
For a general discussion of renal calculi please refer to nephrolithiasis.
Steinstrasse [stīn′shtra-se] is the German word for "stone street", describing a possible complication of extracorporeal shock wave lithotripsy (ESWL) for urinary tract calculi, wherein a column of stone fragments forms that blocks the ureter.
History and etymology
The term was coined by Egber...
The stipple sign refers to the pointillistic end-on appearance on intravenous pyelography or retrograde pyelography of contrast material tracking into the interstices of a papillary lesion. Because the majority of transitional cell carcinomas (TCC) have a papillary configuration, the presence of...
Striated nephrogram, originally described on plain film urography, but just as easily seen on CT urography represents linear bands of contrast extending from the medulla of the kidney towards the cortex.
Striations result from stasis and concentration of contrast material in oedemato...
The string of beads sign is the description typically given to the appearance of the renal artery in fibromuscular dysplasia (FMD) but may also be used to describe the appearance of splanchnic arteries in segmental arterial mediolysis (SAM). It refers to the appearance arising from the stenoses ...
A subcapsular perirenal haematoma is a form of perirenal haematoma where blood accumulates beneath the renal capsular margin.
It can arise from a number of causes
trauma, important in assessing renal trauma grading
post procedural, e.g. extracorporeal shock-wave lithotripsy (ESWL) ...
The sunburst sign refers to the appearance of arterial blush seen at selective arterial DSA angiography of a renal angiomyolipoma.
Angiomyolipoma is a hypervascular renal mass that shows dense early arterial vascular network of tortuous irregular vessels with micro- or macro-aneurysms.
The superficial perineal pouch is an anatomic space below the perineal membrane in the urogenital traingle of the perineum.
The superficial perineal pouch is below the perineal membrane in the urogenital triangle, anterior to the transverse line between the ischial tuberosities.
The superior adrenal (suprarenal) arteries area a group of one of the three adrenal arteries that supply the adrenal gland. There are usually numerous small arteries arising from the inferior phrenic artery.
The superior suprarenal arteries arise from the inferior phrenic...
Supernumerary kidneys are a rare congenital anomaly of the urogenital system, where there are one or two accessory kidneys.
Less than 100 cases are documented.
Patients may be asymptomatic. If present symptoms range from fever, pain to abdominal mass. Thes...
Suprapubic cartilaginous cysts (SPCC) are rare cystic lesions arising from the symphysis pubis thought to be degenerative in origin. They have also been called retropubic or subpubic cysts.
In the small number of cases in the literature, all bar one patient, have been female. The ...
The supravesical fossae are concave depressions of peritoneum in the paravesical space bounded by the median umbilical fold and the medial umbilical folds. It partially overlies the inguinal (Hesselbach’s) triangle. The supravesical fossae are usually occupied by small bowel loops and the urinar...
Syphilis is the result of infection with the gram negative spirochete Treponema pallidum, subspecies pallidum. It results in a heterogeneous spectrum of disease with many systems that can potentially be involved, which are discussed separately.
Despite the discovery of penicillin...
Systemic lupus erythematosus (SLE) is a complex autoimmune disease with multisystem involvement. It is also sometimes classified as a vasculitis.
There is an overall increased female predilection. In adults, women are affected 9-13 times more than males. In children, this ratio i...
Tamm-Horsfall proteins may be a cause of echogenic renal pyramids in a neonate.
Tamm-Horsfall proteins excreted by the renal tubular epithelium. They are most often encountered on neonatal renal ultrasound, where the concentrated proteins in the renal pyramids may mimic nonobstructing renal sto...
Tc-99m DMSA (dimercaptosuccinic acid) is a technetium radiopharmaceutical used in renal imaging to evaluate renal structure and morphology, particularly in paediatric imaging for detection of scarring and pyelonephritis. DMSA is an ideal agent for the assessment of renal cortex as it binds to th...
Tc-99m DTPA (diethylene-triamine-pentaacetate) is one of the technetium radiopharmaceuticals used in renal imaging.
photon energy: 140 KeV
physical half-life: 6 hours
biological half-life: 2.5 hours
normal distribution: kidneys (100%)
uptake by glomerular...
Tc-99m MAG3 (mercaptoacetyltriglycine) is one of the technetium radiopharmaceuticals used in renal imaging.
photon energy: 140 KeV
physical half life: 6 hours
biological half life: 4 hours
normal distribution: kidneys (100%)
uptake by tubular secretion (9...
Tc-99m pertechnetate is one of the technetium radiopharmaceuticals used in imaging of thyroid, colon, bladder and stomach.
photon energy: 140 keV
biological half-life: 6 hours
normal distribution: stomach, thyroid, salivary glands, (testicles)
Technetium agents based on the Technetium-99m (Tc-99m) radioisotope are frequently used agent in medical imaging. The radioactive technetium can be chelated to a number of different compounds to create specific radiopharmaceuticals and optimise imaging of various structures:
Tc-99m ECD (ethyl c...
Teratomas are germ cell tumours that arise from ectopic pluripotent stem cells that fail to migrate from yolk sac endoderm to the urogenital ridge during embryogenesis. By definition, they contain elements from all three embryological layers: endoderm, mesoderm and ectoderm although frequently, ...
The testes (singular "testis" or "testicle") are the male gonads and contained within the scrotum. The testes are responsible for production of sperm and testosterone.
At birth, testes measure approximately 1.5 cm (length) x 1 cm (width), reaching ~4 cc volume at puberty 1.
Testicular abscess is usually a complication of severe epididymo-orchitis and needs to be distinguished from other testicular pathology that may present with similar clinical or imaging features.
The majority of patients develop a testicular abscess as a result of untreated or se...
Testicular adrenal rests are a rare cause of a testicular mass.
Testicular adrenal rests can be known by a variety of terms 2:
testicular adrenal rest tumour (TART)
testicular adrenal rest tissue
testicular tumour of the adrenogenital syndrome
testicular adrenal-like tissue
Testicular and scrotal ultrasound is the primary modality for imaging most of the male reproductive system. It is relatively quick, relatively inexpensive, can be correlated quickly with the patient's signs and symptoms, and, most importantly, is non-ionising.
MRI is occasionally used for probl...
Testicular and epididymal appendages are remnants of embryonic ducts and are quite common, with one or more being present in ~70% of patients 1.
Four such appendages have been described:
testicular appendix (hydatid of Morgagni)
it is a Müllerian duct remnant (paramesonephric d...
A testicular appendix (alternatively called appendix of testis or appendix testis) represents a developmental remnant of the paramesonephric duct (Müllerian duct) which is situated in the upper pole of the testis inside a groove between the testicle and the head of epididymis 1.
The testicular arteries (also known as the spermatic arteries) are the long, small-diameter gonadal arteries in the male that supply the testis alongside the cremasteric artery and the artery to the ductus deferens.
As paired structures they arise symmetrically, slightly...
Testicular cancers are the most common neoplasm in men between the ages of 20 and 34.
Testicular cancer is uncommon, accounting for less than 1% of all internal organ malignancies 2.
The demographics of affected individuals depends on the age of the histology of the tumour. Over ...
The staging for testicular tumours is performed according to the TNM system with staging groupings. It can be remembered in its abbreviated form as:
stage I: confined to testis, epididymis, spermatic cord, scrotum
stage II: lymph nodes involved but no distant metastases and serum tumour marke...
Simple testicular cysts are usually nonpalpable and thus are detected incidentally.
Testicular cysts require no treatment when discovered.
On US, testicular cysts are usually well-defined and anechoic with enhanced through transmission and an imperceptible wa...
Testicular epidermoid cysts, also known as keratocysts, are rare benign tumours of germ cell origin that occur in the testis.
Testicular epidermoid cysts account for around 1-2% of all testicular masses and typically present in mid-adulthood (2nd to 4th decades) 1,2. They are the...
Testicular germ cell tumours account for 90% of primary tumours of the testes. They are the most common nonhematologic malignancy in men 15-49 years old.
They are divided into:
testicular seminoma: 40% of germ cell tumours 1
non-seminomatous germ cell tumour: 60% of germ cell tumours
Testicular leukemia can be seen in patients during and after acute leukemia. The blood-testis barrier limits chemotherapy from reaching the testicle, and therefore the testicle can act as a harbor for leukaemic cells.
Typically presents with painless testicular enlargemen...
Testicular lymphoma is an uncommon cause of testicular malignancy. Lymphoma can involve the testes in three ways:
primary site of extranodal disease (primary testicular lymphoma)
secondary involvement of systemic disease
primary manifestation of subclinical systemic disease
This article is c...
Testicular microlithiasis (TM) is a relatively common condition that represents the deposition of multiple tiny calcifications throughout both testes.
The diagnosis is only made with more than five calcifications are detected. In the vast majority of cases testicular microlithiasis is bilatera...
Testicular mixed germ cell tumours are, as the name suggests, testicular tumours composed of two or more types of germ cell tumour. They are considered to be part of non-seminomatous germ cell tumours, as it is that component which dictates prognosis and treatment.
Overall they account for ove...
Testicular seminomas are the most common testicular tumours and account for ~45% of all primary testicular tumours. This article concerns itself only with testicular seminomas, however, seminomas can arise outside of the testicle most often within the anterior mediastinum, e.g. anterior mediasti...
Testicular teratoma, unlike ovarian teratoma, is often aggressive in its biological behaviour, and often exists as part of testicular mixed germ cell tumours.
Pure testicular teratomas account for only 4-9% of all testicular tumours. A similar number are seen in the context of t...
Testicular torsion occurs when a testicle torts on the spermatic cord resulting in the cutting off of blood supply. The most common symptom is acute testicular pain and the most common underlying cause, a bell-clapper deformity. The diagnosis is often made clinically but if it is in doubt, an ul...
Testicular trauma is the third most-common cause of acute scrotal pain and may result in various degree of damage to the testes.
Testicular rupture and testicular ischaemia/infarct are two severe complications which need to be ruled out. Other injuries that can occur include 1:
Testicular yolk sac tumours (also known as endodermal sinus tumour of the testis) is the most common childhood testicular tumour (80%), with most cases occurring before the age of two years 1. In adults, pure yolk sac tumour is extremely rare, however mixed germ cell tumour are commonly seen.
The threads and streaks sign refers to an angiographic appearance of a vascularised tumour thrombus extending into the ipsilateral renal vein or the inferior vena cava from a renal cell carcinoma. This gives an appearance of linear, thread like or string like appearance of the involved vessel.
Throckmorton sign, also known as John Thomas sign, refers to when the penis points in the direction of unilateral disease, typically of the pelvis or hip.
Throckmorton sign is a slang term used jokingly by medical students and residents.
History and etymology
It is named after Tom Bentley Th...
Torsion of the appendix testis is the most common cause of an acute painful hemiscrotum in a child. The appendix testis is located at the upper pole of the testis (between the testis and the head of the epididymis).
The normal appendix testis is 1 to 4 mm in length, and it is oval or pedunculat...
Transitional cell carcinoma (TCC) is the most common primary neoplasm of the urinary bladder, and bladder TCC is the most common tumour of the entire urinary system.
This article concerns itself with transitional cell carcinomas of the bladder specifically. Related articles include:
Transitional cell carcinoma of the renal pelvis is uncommon compared to renal cell carcinoma and can be challenging to identify on routine imaging when small.
This article concerns itself with TCCs of the renal pelvis specifically. For a general discussion of this tumour please see transitiona...
Staging of transitional cell carcinomas of the urinary tract vary according to the location of the tumour, and are staged using the TNM staging system.
transitional cell carcinoma of the renal pelvis
transitional cell carcinoma of the ureter
transitional cell carcinoma of the bladder
Transitional cell carcinoma of the ureter are uncommon compared to similar tumours elsewhere along the urinary tract but are nonetheless the most common primary tumour of the ureter.
This article concerns itself with transitional cell carcinomas of the ureter specifically. For a general discuss...
Transitional cell carcinoma of the urethra is rare and is limited to the proximal urethra in men (membranous and prostatic). The vast majority of urethral tumours are squamous cell carcinomas.
squamous cell carcinoma of the urethra
transitional cell carcinoma
Transitional cell carcinoma (TCC), also called urothelial cell carcinoma (UCC), is the most common primary malignancy of the urinary tract and may be found along its entire length, from the renal pelvis to the bladder.
As imaging findings and treatment vary according to where along the urinary...
Transitional cell carcinomas of the urothelium are graded histologically as follows:
transitional cell papilloma
benign tumour, not a carcinoma but sometimes included in classification systems
carcinoma in situ
do not penetrate the basement membrane
cells resemble those of grade II or III ...