IS Case 334: Epididymal cyst versus spermatocele

Richard Gong, MD

Imaging Sciences URMC 2009
Publication Date: 2009-09-15


Patient is a 17-year-old male with right testicular pain.


Ultrasound image of the right epididymis demonstrates an anechoic cystic structure. Scrotal ultrasound was otherwise normal with symmetric intratesticular flow.


Epididymal cyst versus spermatocele


Epididymal cysts are benign lesions that most commonly present after a "testicular" mass is noted on physical exam or incidentally noted on ultrasound evaluation for testicular pain. While the etiology of epididymal cysts is not known for certainty, they have been reported in association with diethylstilbestrol (DES) use, cryptorchidism, cystic fibrosis and von Hippel-Lindau disease.

On ultrasound, they appear as anechoic cystic structures within the epididymis. In post-pubertal males, spermatoceles have similar sonographic characteristics. Aspiration of sperm from a spermatocele is the only definitive way to differentiate the two entities.

The functional significance of epididymal cysts is not known. They usually regress with time and conservative management is the norm. Surgical intervention should be reserved for persistent or worsening symptoms.


  1. Homayoon K, Suhre CD, Steinhardt GF. Epididymal cysts in children: natural history. J Urol. 2004 Mar;171(3):1274-6. PMID: 14767330

2 images