How large (in cm) does a renal cyst need to be to require surgery?

Whether kidney cysts require surgery mainly depends on the size, location, and whether they are causing related symptoms. Generally speaking, surgery needs to be considered when the diameter of the kidney cyst exceeds 5 cm, or when it is smaller than 5 cm but has already caused significant symptoms (such as flank pain, hematuria, hydronephrosis, etc.). The main purpose of surgery is to relieve the pressure of the cyst on surrounding tissues and protect kidney function. Commonly used surgical methods include laparoscopic cyst decortication and ultrasound-guided cyst aspiration with sclerotherapy. The former is a minimally invasive procedure that achieves therapeutic effects by removing the cyst wall and draining the cystic fluid; the latter is suitable for patients who are unwilling to undergo general anesthesia or have poor physical condition, and involves aspirating the cyst fluid through puncture and injecting a sclerosing agent to reduce the cyst size.