Rare, benign, keratin-containing lesion of controversial origin

High-resolution ultrasound (≥ 10 MHz) is imaging modality of choice

Grayscale ultrasound

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  Characteristic onion skin, concentric rings, or target/bull’s-eye appearance of testicular mass

  
  
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  Unilocular cyst containing keratin; fibrous wall

  
  
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  Sharply circumscribed, encapsulated round “mass”

Color Doppler ultrasound

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  Avascular, no blood flow demonstrable

Most commonly intratesticular but rarely may be extratesticular

Tunica albuginea cyst

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  Located within tunica, solitary, unilocular, and anechoic

Germ cell tumor

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  Heterogeneous mass with vascularity seen on Doppler

Testicular granuloma

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  Most probably due to TB, usually multiple

May occur at any age; 2nd-4th decades most common

1-2% of all testicular tumors

No malignant potential

Enucleate 1st if lesion < 3 cm with characteristic ultrasound appearance and no color flow; testis can be spared if

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  Frozen sections of lesion are consistent with epidermoid cyst

  
  
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  No evidence of malignancy within or surrounding lesion

  
  
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  Negative tumor markers (AFP, β-HCG)

Lesion should be avascular on color Doppler