Suggest Treatment For Cyst In Ovary Of Woman With Scleroderma

I am a 69 year old Anglo woman who has had scleroderma (CREST) since 1977. A recent CAT scan and pelvic ultrasound show that I have a cyst on my right ovary about 4 centimeters in width. Question is should I have it removed to see if it is malignant, and if it is positive for cancer, can it be treated since I have a lowered immune system due to scleroderma?