Hi I had back pain in 07 they found a 7cm semi complex cyst on my left kidney...I was told not to worry as they are common and rarely cancerous...however I just felt ill and had flank pain finally I asked for a second opinion at a large teaching hospital (Dartmouth Hitchcock) well the urologist had a different opinion and recommended it be removed to make a long story short it was cancerous and I most likely wouldn't be writing this post had I gone with the first local doctor..I had stage 2 renal carcinoma...lost most of my left kidney and my adrenal gland...I’m still not out of the woods and still can’t believe the first urologist just blew of the calcification which is a sign of possible cancer because the cyst is changing just go to web M.D...Please follow up on this jcjwd