Hydrocele: Collection of fluid in space around the testis. This causes testicular enlargement, demonstrated in the picture on the left. The fluid allows for the passage of light, known as transillumination, apparent in the picture on the right. Charlie Goldberg, M.D. - UCSD Catalog of Clinical Images #Clinical #Photo #Hydrocele #Scrotom #Scrotal #Transillumination #UCSDH