Testes

4 x 3 x 2 cm, 15-20 ml, rete testes located in the testicular mediastinum connects to the epididymal head, arterial waveform have low-resistance pattern (like other solid parenchymal organs)

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Spermatocele

Most common scrotal mass, hypoechoic w/ low level echoes.

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Epididymal head cysts

Undistinguishable from spermatoceles (70% of scans).

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Hydroceles

Forms in the potential space of the tunica vaginalis, anterior aspect of the scrotum. Hydrocele of the spermatic cord --> funiculocele superior to epididymal head

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Varicoceles

Left spermatic vein drains into the left renal vein, Right spermatic vein drains into IVC. Because SMA compresses left renal vein, the pressure on left side is higher than on right → 85% of varicoceles are on left. Remaning 15% are bilateral. It is very unusual to have isolated right sided varicocele → look for retroperitoneal masses which compress right spermatic vein (do abdominal survey). Dilaed vein > 2 mm, Valsalva --> retrograde flow into the pampiniform plexus. Other less frequent extratesticular masses: Scars, Sperm cell granulomas, chronic hematomas, Hernias, Scrotal wall edema, Scrotoliths, Adenomatoid tu

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Testicular cyst

(10% of scans) elderly, in the mediastinum, if simple --> ignore. If complex (multiseptated, internal echoes, solid components, thick wall, blood flow) consider cystic tumor (teratoma)

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Tunica albuginea cyst

Very firm, easily palpable, if simple --> ignore.

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Tubular ectasia of the rete testis

Multiple small tubular cystic spaces in the enlarged mediastinum

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Testicular neoplasms

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Germ Cell Tumors

Most common neoplasm in young men, nontender mass. SETCHMY: Seminomatous and non-seminomatous tumors

• Seminoma (homogeneous hypoechoic, w/ or w/o Doppler flow)
• Embryonal cell ca
• Teratoma (hypervascular)
• Choriocarcinoma
• Yolk sac tumor
• Mixed germ cell tumor (all of above - heterogeneous, calcifications, cystic elements)

Detectable flow. Scan retroperitoneum near the kidney to look for nodal mets and vice versa → Retroperitoneal adenopathy in a young adult male is suspicious for a testicular tumor → if US of testes is negative order MRI

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Stromal tumors

Leydig cell tu, Sertoli cell tu. Hypoechoic to hyperechoic. Majority bng, hormonal changes, always removed because they cannot be distinguished from Germ Cell Tumors. Mets.

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Epidermoid cyst

Hypoechoic masses w/ hyperechoic calcified rim or concentric internal laminations --> onion slice. Th: enucleated w/ preservation of the rest of the testis.

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Lymphoma, Leukemia

Testes are sanctuary, chemotherapy doesn’t cross blood-testis barrier

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Tumor mimickers

Infarcts, focal orchitis, focal atrophy/fibrosis, hematomas, abscesses, contusion, sarcoid, tuberculosis, TART: Testicular Adrenal Rest Tissue (Tumor)

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Testicular microlithiasis

5 or more microliths seen on at least one image. Tiny, non-shadowing bright reflectors. 10% will have a testicular Germ Cell Tumor at the time of dx.

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Plaque of tunica

Calcifications of tunica albuginea after trauma

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Undescended testes

In inguinal canal or in retroperitoneum. 40 x higher risk for Germ Cell tumors, risk eliminated if orchiopexy before 5 yo, orchiectomy between 5-10 yo

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Testicular torsion

Predisposition Bell-Clapper deformity --> tunica vaginalis completely surrounds testis, testis attached only to spermatic cord (clapper in a bell). Absent Doppler flow, knot, reactive hydrocele, infarctions as soon as 4 hours since insult, surgery in 6h -12h. Nonviable testis: hypoechoic, inhomogeneous, hyperemic scrotal wall

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Epididymoorchitis

Enlarged, hypoechoic epididymis and testes, inflammatory hyperemia, epididymal and testicular abscess.

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DDx: Enlarged hypoechoic testis: Torsion, Lymphoma, Leukemia, diffuse Seminoma ⇒ focal orchitis needs to be followed

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Testicular trauma

Management based on status of tunica albuginea. if ruptured --> surgery in 72h to maintain viability. Areas of non-specific hyper or hypoechogenicity, misshapen and distorted testis, subcapsular hemorrhage