A 9cm cyst from endometriosis is significant, and whether surgery or medicine works better depends on your symptoms, the cyst type, and your fertility plans. This isn't a one size fits all decision.
Next Steps
Get a pelvic ultrasound and see a gynaecologist who can weigh both options against your plans to conceive.
Health Tips
Endometriosis doesn't mean pregnancy is impossible, but a cyst this size shouldn't go unmonitored.