Varicocele is abnormal dilatation of the pampiniform venous plexus veins and is one of the most common treatable causes of male infertility. It occurs on the left side in 85-90% of cases (due to the left testicular vein draining at a right angle into the left renal vein). Ultrasound is the primary imaging modality; anechoic tubular structures >3 mm in diameter on B-mode and retrograde venous flow increasing with Valsalva maneuver are pathognomonic findings. Varicocele is found in 15-20% of men and detected in 35-40% of infertile men. Isolated right-sided varicocele requires further investigation to exclude retroperitoneal pathology (renal vein tumor, IVC thrombosis). Clinically graded as grade I (palpable only with Valsalva), grade II (palpable standing), and grade III (visible).
Age Range
15-45
Peak Age
25
Gender
Male predominant
Prevalence
Common
Varicocele results from blood pooling and dilatation of pampiniform venous plexus veins due to valve insufficiency in the testicular vein or the left testicular vein draining at a right angle into the left renal vein. Left-sided predominance is explained by anatomical reasons: the left testicular vein drains into the left renal vein at a right angle (90 degrees) while the right testicular vein drains into the IVC at an oblique angle — this right angle impairs venous return and facilitates gravitational reflux. Nutcracker phenomenon (compression of the left renal vein between SMA and aorta) is an additional factor increasing left varicocele incidence. Venous stasis and increased scrotal temperature adversely affect spermatogenesis — this is the basis of the infertility mechanism. Dilated veins appear as anechoic tubular structures >3 mm on ultrasound; Valsalva maneuver triggers increased intra-abdominal pressure worsening venous reflux and further increasing vein diameter. Venous reflux (retrograde flow) is directly visualized on Doppler. In late stages, chronic venous stasis may lead to testicular atrophy (decreased testicular volume).
Demonstration of retrograde venous flow in dilated pampiniform veins during Valsalva maneuver — pathognomonic diagnostic criterion for varicocele. Retrograde flow >2 seconds duration is considered pathological.
Multiple anechoic tubular structures >3 mm in diameter are seen in the paratesticular area and along the spermatic cord. Veins typically course along the posterior and superior aspects of the testis. Vein diameters are more prominent in upright examination (gravitational effect). Vein diameters decrease in supine position. Vein diameters: Grade I (<3 mm, exceeds 3 mm with Valsalva), Grade II (3-5 mm at rest), Grade III (>5 mm at rest). 'Bag of worms' appearance in the spermatic cord is classic.
Report Sentence
Multiple dilated tubular venous structures >3 mm are seen in the left paratesticular area; appearance is consistent with varicocele.
Retrograde (reverse direction) venous flow is observed in dilated pampiniform veins during Valsalva maneuver on color and spectral Doppler. At rest, flow may be stagnant or slow antegrade; with Valsalva, flow direction reverses and flow velocity increases. Retrograde flow duration >2 seconds is considered pathological. On spectral Doppler, a waveform below baseline is seen during Valsalva (reverse flow). This finding is the most important Doppler criterion confirming varicocele diagnosis.
Report Sentence
Retrograde venous flow >2 seconds duration is observed in the pampiniform veins during Valsalva maneuver on spectral Doppler; finding is consistent with varicocele.
Ipsilateral testicular volume decrease (atrophy) is seen in chronic varicocele. Testicular volume is calculated using the ellipsoid formula (length x width x depth x 0.52). Volume difference >20% compared to contralateral testis is considered clinically significant. Testicular atrophy indicates impaired spermatogenesis and may constitute indication for surgery (varicocelectomy).
Report Sentence
Left testicular volume is reduced by >20% compared to the right testis, raising concern for varicocele-related testicular atrophy.
CT is not the primary imaging modality for varicocele but dilated gonadal vein and retroperitoneal pampiniform plexus may be incidentally seen on abdominal CT. CT's main role is to exclude retroperitoneal pathology (renal cell carcinoma with renal vein invasion, IVC thrombosis, retroperitoneal lymphadenopathy) in isolated right-sided or new-onset varicocele. Dilated left gonadal vein can be traced to the left renal vein; Nutcracker phenomenon (left renal vein compression between SMA and aorta) is evaluated on CT.
Report Sentence
Dilatation of the left gonadal vein is seen on CT with no retroperitoneal pathology identified.
On MRI, multiple dilated venous structures in the paratesticular area may appear as high signal on T2 (slow flow) or flow voids (fast flow). MR venography can demonstrate gonadal vein anatomy and reflux. MRI's main role is evaluating left renal vein compression and alternative venous drainage pathways in suspected Nutcracker syndrome. MRI can also evaluate atrophic changes in testicular parenchyma.
Report Sentence
Multiple dilated venous structures are seen in the paratesticular area on MRI; findings are consistent with varicocele.
Rarely, intratesticular varicocele is seen — dilated venous structures within testicular parenchyma. Typically located around the testicular mediastinum. B-mode shows anechoic tubular structures, Doppler shows venous flow with increase on Valsalva. Intratesticular varicocele may be isolated or associated with extratesticular varicocele. Differentiation from hypoechoic intratesticular lesions (tumor) is important — Doppler demonstrating venous flow is diagnostic.
Report Sentence
Intratesticular dilated venous structures are seen around the testicular mediastinum with diameter increase on Valsalva; consistent with intratesticular varicocele.
Criteria
Palpable or visible on physical examination. Grade II: palpable standing, disappears supine. Grade III: visible standing (bag of worms). US shows >3 mm at rest (Grade II) or >5 mm (Grade III).
Distinct Features
Varicocelectomy indication if infertility or testicular atrophy present. US provides objective vein diameter measurement and reflux duration assessment aiding surgical decision.
Criteria
Not palpable on physical examination, detected only on US with Valsalva. Resting vein diameter <3 mm, with Valsalva >3 mm and retrograde flow. Surgery for subclinical varicocele is controversial.
Distinct Features
Diagnosed by US — cannot be diagnosed without Doppler. Clinical significance controversial — surgical indication evaluated based on sperm parameters.
Criteria
Varicocele resulting from retroperitoneal pathology (renal cell carcinoma renal vein invasion, IVC thrombosis, retroperitoneal mass) obstructing testicular venous drainage. New onset, isolated right-sided, or varicocele not decompressing supine is suspicious.
Distinct Features
Isolated right side OR not decompressing supine OR new onset = abdominal CT retroperitoneal investigation MANDATORY. Renal vein tumor must be excluded.
Distinguishing Feature
Spermatocele: anechoic cyst at epididymal head, unchanged with Valsalva, NO flow on Doppler. Varicocele: multiple tubular structures, increases with Valsalva, venous flow PRESENT on Doppler.
Distinguishing Feature
Simple cyst: solitary, round, anechoic, posterior acoustic enhancement, no flow on Doppler, unchanged with Valsalva. Varicocele: multiple, tubular, changes with Valsalva, venous flow on Doppler.
Distinguishing Feature
Torsion: avascular testis, whirlpool sign, acute pain. Varicocele: vascular dilated veins, retrograde flow, chronic/asymptomatic or dull ache.
Distinguishing Feature
Adenomatoid tumor: paratesticular solid mass, well-defined, homogeneous, unchanged with Valsalva. Varicocele: tubular anechoic structures, increases with Valsalva, venous flow on Doppler.
Urgency
routineManagement
conservativeBiopsy
Not NeededFollow-up
annualVaricocele is generally a benign condition. Treatment indications: infertility + abnormal sperm parameters, testicular atrophy (>20% volume difference), symptomatic (pain). Varicocelectomy (surgical ligation or embolization) improves sperm parameters in 60-80% of cases. Retroperitoneal pathology must be excluded in isolated right varicocele or new-onset varicocele. Surgery for subclinical varicocele is controversial.
Varicocele is the most common correctable cause of male infertility. It negatively affects semen parameters (oligospermia, asthenozoospermia, teratozoospermia). Surgical (varicocelectomy) or endovascular embolization are treatment options. Isolated right-sided varicocele is a red flag for retroperitoneal pathology (especially renal cell carcinoma with left renal vein invasion or IVC obstruction) and warrants abdominal imaging. Grade III varicocele and presence of testicular atrophy are indications for surgical treatment.