I. How are renal cysts formed? Most simple cysts are mostly formed later in life, initially due to obstruction of renal tubules blocking the formation of small diverticula, and then the fluid continues to accumulate and the diverticula continue to grow in size and form cysts. Polycystic kidneys, on the other hand, are mainly due to congenital hereditary factors, with genetic defects, resulting in the appearance of numerous cysts of varying sizes on both sides of the kidneys. Traditional Chinese medicine believes that kidney cysts are mostly due to congenital heredity or loss of nourishment after birth, damaged kidney qi, collaterals and veins, resulting in kidney blood and water coalescence and cystic diseases of the internal organs. Is it dangerous to have cysts in the kidney? The vast majority of renal cysts are asymptomatic and usually do not have a great impact on human health. Some patients may have the following symptoms due to increased pressure within the cyst, bleeding from the cyst, associated infections and other triggers: 1) Lumbar and abdominal discomfort or pain: the pain is characterized by vague pain, dull pain, fixed on one side or both sides, radiating to the lower abdomen and lower back. If there is intracapsular hemorrhage or secondary infection, the pain is suddenly aggravated. If the combination of stones or bleeding blood clots obstruct the urinary tract, colic can occur. (2) Hematuria: it can be microscopic hematuria or carnal hematuria, which can be periodic. Lumbar pain increases during the attack, and can be induced or aggravated by strenuous exercise, trauma, and infection. 3）Abdominal mass: used to be the main reason for patients to consult the doctor, 60%～80% of patients can palpate the enlarged kidney. 4）Hypertension: it can be caused by cysts compressing the kidneys, resulting in renal ischemia and causing hypertension, and the incidence of hypertension is higher when renal function decreases. 5) Proteinuria: can be seen in some patients, usually the amount of urinary protein is not much. 6) Renal hypoplasia: due to the long-term compression of cysts on renal parenchyma, the normal renal tissue shrinks significantly and renal function decreases progressively. 7) Malignant transformation of renal cysts to form renal cancer: about 3% to 7% of renal cysts may become malignant, which need to be detected in time and treated actively. Most of the small cysts do not need special treatment, but any of the above symptoms will have impact on your health when the condition is serious. Our advice is to decide whether to take action on your cysts under the guidance of professional doctors. Do kidney cysts need treatment? What are the main treatment methods? If the cyst is small and the patient does not have any uncomfortable symptoms, no treatment is needed for the time being; however, it is important to have regular checkups to observe whether the cyst continues to grow and how fast it grows. If the cyst is symptomatic or large (diameter >5~10cm), laparoscopic renal cyst debridement and decompression is the first choice after malignant tumor is ruled out – the “roof” of the cyst is lifted off to prevent the cystic fluid from accumulating because large cysts will cause compression of the normal renal tissue. The advantage is that it is less invasive and less likely to recur. The advantages of this procedure are that it is less invasive and has a lower recurrence rate. If you suspect that the cyst has the possibility of malignant transformation, you should have a timely surgical investigation, and if necessary, the renal occupation should be completely removed. How to determine the malignancy of renal cyst? Clinicians can grade renal cysts by ultrasound and CT, which is called “Bosniak grading system”. Grade I cysts: simple benign cysts with thin walls, no segregation or calcification, and watery cyst fluid; Grade II cysts: benign cysts with small segregation and calcification points, and no enhancement of segregation; Grade III cysts: thick walls, many segregation and calcification within the cyst, and enhancement of segregation, and more than 50% of the cysts are malignant cysts; Grade IV cysts: malignant cysts with enhancement of the soft tissue components within the cysts. For grade I~II cysts, observation and follow-up can be an option, while grade III~IV cysts should be surgically explored and removed as soon as possible. Therefore, if you find an extra cyst on your kidney during physical examination, please be sure to come to our hospital and let the professional doctor read the film for you!