I 89 Years Old And On An MRI For Low

I 89 years old and on an MRI for low back pain, an ovarian cyst was found on my right ovary. I had a TAH when I was 39 for fibroids and the left ovary was removed for a cyst. I have been advised to have an abd. CT scan . I have had no pain or other symptoms and will be 90 this year and don't want to have any invasive procedures. What is the worst case scenario.