Hello, testes are oval organs about the size of large olives that lie in the scrotum, secured at either end by a structure called the spermatic cord. Most men have two testes. The testes are responsible for making testosterone, the primary male sex hormone, and for generating sperm. Within the testes are coiled masses of tubes called seminiferous tubules. These tubes responsible for production of sperm. Sometimes size variation will be there between two testes. If actual mass is there reasons may be conditions like 1)Testicular cancer: Testicular cancer is a tumor containing abnormal testicular tissue, which can usually be felt as a lump in the scrotum.
2)Spermatocele: Also known as a spermatic cyst or epididymal cyst, spermatocele is a typically painless, noncancerous (benign), fluid-filled sac in the scrotum, usually above the testicle.
3)Epididymitis: This is inflammation of the epididymis, the comma-shaped structure above and behind the testicle that stores and transports sperm. Epididymitis is often caused by a bacterial infection, including sexually transmitted bacterial infections, such as chlamydia.
3)Orchitis: This is inflammation of the testicle usually due to a viral infection — most commonly mumps. When orchitis is caused by a bacterial infection, the epididymis also might be infected.
4)Hydrocele: Hydrocele occurs when there is excess fluid between the layers of a sac that surrounds each testicle.
4)Hematocele: Hematocele occurs where there is blood between the layers of a sac that surrounds each testicle. Traumatic injury, such as a direct blow to the testicles, is the most likely cause.
5)Varicocele: This is the enlargement of the veins within the scrotum that carry oxygen-depleted blood from each testicle and epididymis. Varicocele is more common on the left side of the scrotum because of differences in how blood circulates from each side. A varicocele might cause infertility.
7)Testicular torsion: This is a twisting of the spermatic cord, the bundle of blood vessels, nerves and the tube that carries semen from the testicle to the penis. Consult general physician for furthur evaluation and treatment.