• A benign cystic dilatation in the head of the epididymis that contains milky or watery fluid and spermatozoa.
  NCI Thesaurus
  U.S. National Cancer Institute, 2021
• A cystic dilation of the EPIDIDYMIS, usually in the head portion (caput epididymis). The cyst fluid contains dead SPERMATOZOA and can be easily differentiated from TESTICULAR HYDROCELE and other testicular lesions.
  NLM Medical Subject Headings
  U.S. National Library of Medicine, 2021
• A cystic structure arising from the epididymis, rete testis or efferent ductuli. These structures are filled with spermatozoa containing fluid that may be milky. These cysts are usually outside the tunica vaginalis and, as with hydrocele, transluminate easily.
  Human Phenotype Ontology (HPO)
  The Human Phenotype Ontology Project, 2021
• A spermatocele is a benign cystic accumulation of sperm that arises from the head of the epididymis. Although often disconcerting to the patient when noticed, these lesions are benign.
  Medscape
  WebMD, 2019
• A spermatocele (SPUR-muh-toe-seel) is an abnormal sac (cyst) that develops in the epididymis - the small, coiled tube located on the upper testicle that collects and transports sperm. Noncancerous and generally painless, a spermatocele usually is filled with milky or clear fluid that might contain sperm.
  Mayo Clinic
  Mayo Foundation for Medical Education and Research