What Causes Backache Along With Fatigue And Abdominal Distention?

Hi, I recently was diagnosed with possible kidney cancer. during a CT scan for a possible abdominal blockage or appendicitis, a lesion was seen on my left kidney. After an ultrasound, it was determined that the lesion was indeed a solid mass indicative of Kidney cancer. I have an appointment with a Urologist in a week. I have many of the symptoms: back pain, fatigue, etc.. however over the weekend, I developed a bulge on the mid section of my belly, near where I ve had flank pain. This concerns me because it was not there on Friday, and Saturday it was there and very pronounced as well. I have a lot of flank pain and am feeling worse day by day. I just read that a belly/side bulge can be due to the cancer being further along. The tumor is only 13 mm, so it s not very big. how concerned should I be with the lump in my side/belly? could this be a fast growing type of cancer and how strange is it that all of a sudden, out of nowhere, this lump showed up? Thank you. nowhere on here did it mention any kind of cost involved. I guess I will wait until Tuesday. Thanks anyway.