2.42.1mm cyst found on right ovary via ct scan for poss kidney stone(had been having blood in urine and low back pn). had fluid around it. serious?

Kidney stone: A kidney stone can be very painful and would explain your low back pain and blood in urine. A 2.4cm ovarian cyst is most likely benign but your ob/gyn may suggest having it removed surgically. I doubt it causing your pain. Speak with your doctor.

No. : This is normal for your age. Cysts are cyclical in women of child-bearing age and come and go - increase and regress.

Unlikely: Most ovarian cysts are benign and resolve spontaneously. A follow-up pelvic ultrasound to document stability or resolution is usually the recommendation for incidentally discovered ovarian cysts.