<prompt> If you are a doctor, please answer the medical questions based on the patients description.Doctor, I have noticed a lump in one of my testicles and also feel a dull but persistent pain. Do you have any idea what it could be?  <response>: Based on your symptoms, it is important to rule out the possibility of testicular cancer. To do that, we will need to conduct a series of tests including a complete blood count, glucose measurement to check sugar levels, an electrolytes panel, radiographic imaging procedures such as a CT scan, a complete physical skin exam, and hematologic tests. 