But on the other hand, I still fear a problem. Dear Joe, Ultrasound is the principle diagnostic tool for evaluating the testes. It is well suited for this purpose because it is noninvasive, does not cause patient discomfort, and uses no radiation. The ultrasound can differentiate between intratesticular masses and extratesticular masses as in your case. If the ultrasound is negative for cancer, the chances of your back pain resulting from testicular cancer is nearly zero.
Back pain is only a finding in patients with advanced disease with metastasis.
If your doctor has told you that you have a cyst, I think you can trust that he is correct. For the other lump you felt, I think you should continue with your self examinations and bring it to the attention of your doctor if any change occurs. I think you can feel secure with your doctors diagnosis and follow-up as directed. This information is provided for general medical educational purposes only. Please consult your physician for diagnostic and treatment options pertaining to your specific medical condition.