1 extra blob in the left testicle may be testicular cyst, testicular syringomyelia, varicocele, testicular tumor, etc. 1. Testicular cyst: the small ball in the left testicle may be a testicular cyst, which is a benign lesion of the testicle. Most patients have no obvious symptoms, and with the gradual increase of the cyst, there may be pressure and pain. 2. Syringomyelia: usually caused by inflammation or surgical trauma to the testicles, there may be swelling in the scrotum, often accompanied by a feeling of falling and pain. Therefore, the small ball of the left testicle may also be syringomyelia. 3. Varicocele: Varicocele on the left side of the testicle can present as a mass or nodule, so the extra bulge in the left testicle may be caused by varicocele. 4. Testicular tumor: the possibility of testicular tumor can not be ruled out, with the increase of the tumor, patients also have the feeling of swelling or dull pain. It is recommended that the patient should consult the doctor in time, carry out the corresponding examination to clarify the cause, and carry out the corresponding treatment under the guidance of the doctor.