I was diagnosed with a 4.6 cm. thanks renal cyst with calcified septations when I was recently went to the hospital for a kidney stone. I was kidney stone free for one year after I had shock wave therapy to remove 8 kidney stones in 2013. A year later during a check up I was completely stone free and know sign if a cyst. Does anybody know if a cyst can grow to 4.6 can. In 4 years.? How long dies it normally take for a renal cyst to grow to almost the size if a tennis ball? Has anyone else experienced the shock of finding this out and not understanding how it grew to such a large size within 4 years? I didn't even have a cyst in 2014.Is there anybody out there that know how long it takes for a renal cyst to grow to 4.6 cm.