Spermatocele is a retention cyst of a tubule of the rete testis or the hea of the epididymis distended with a milky fluid that contains spermatozoa. Spermatoceles are the most common cystic condition encountered within the scrotum. They vary in size from several millimeters to many centimeters. Spermatoceles are generally not painful. However, some men may experience discomfort from larger spermatoceles.