Results from accumulation of serous fluid between parietal and visceral tunica vaginalis of the testis.
Congenital hydrocele occurs when a patent processus vaginalis within the spermatic cord communicates with the peritoneal cavity.
Prevalence of congenital hydrocele: 6% at birth and 1% in adulthood.
Most cases are idiopathic but may be associated with trauma, inguinal hernia, epididymoorchitis, or tumors of the testicular/ paratesticular region.
Possible causes may include excessive secretion within the testicular tunics by parietal mesothelial cells, decreased reabsorption, and congenital absence of the efferent lymphatics.
Gross: translucent cyst filled with clear or serous fluid (unless there has been trauma or secondary infection).
Hydrocele is lined by a single layer of cuboidal or flattened mesothelial cells, sometimes with prominent atypia.
Underlying connective tissue stroma with or without fibrosis and chronic inflammation.
In some cases progressive fibrosis narrows or obliterates the cyst lumen, creating adhesions and multiple cysts.
Fluid should not contain sperm unless a spermatocele has ruptured into the hydrocele sac.