I. What is a kidney cyst? What are the types of kidney cysts? Kidney cyst is a cystic lesion on the surface or inside of the kidney that does not communicate with the outside world. According to the cause of disease, there are two kinds of renal cysts: congenital and acquired. Congenital, also known as hereditary renal cysts, commonly include polycystic kidney, medullary sponge kidney and polycystic renal dysplasia. Acquired ones are simple renal cysts, parapelvic cysts and acquired cystic nephropathy, the latter is mostly seen in uremia and long-term dialysis patients. Simple renal cysts are the most common in the clinic. How are renal cysts formed? Most simple cysts are formed later in life, initially due to obstruction of the renal tubules to block the formation of small diverticula, and then the fluid continues to accumulate, the diverticula continue to grow 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 not harmonious, resulting in kidney blood and water coalescence and the internal organs of cystic diseases. Third, what are the symptoms of kidney cysts? 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 blocking the urinary tract, colic can occur. 2.Hematuria: it can be microscopic hematuria or carnal hematuria, which can be periodic. Lumbar pain is aggravated during the attack, which can be induced or aggravated by strenuous exercise, trauma, infection. 3.Abdominal mass: it used to be the main reason for patients to consult the doctor, 60%～80% of patients can touch the enlarged kidney. Hypertension: cysts can compress the kidneys and cause renal ischemia, which activates the renin-angiotensin system, and increased secretion of renin and angiotensin can cause hypertension. The incidence of hypertension is higher when the renal function is reduced. Proteinuria: it can be seen in some patients, and the amount of urinary protein is not much. 6, Renal hypoplasia: due to the long-term compression of cysts on the renal parenchyma, the normal renal tissue shrinks significantly, and the renal function decreases progressively. 7.Malignant transformation of renal cysts and formation of renal cancer, about 3% to 7% of renal cysts may become malignant, which need to be detected in time and actively treated. Most of the small cysts do not need special treatment, but any of the above symptoms will have an 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. What are the auxiliary tests for kidney cyst? Urine routine: mostly normal, if the cyst compresses the renal parenchyma or combined with intracystic infection, a small amount of red blood cells and white blood cells can appear in the urine. 2, B ultrasound: can understand the number of cysts, size, cyst wall. And can be identified with renal mass, for the preferred method of examination. Typical ultrasound performance for the lesion area is no echo, smooth cyst wall, clear boundaries; when the cyst wall shows irregular echo or limited echo enhancement, should be vigilant for malignant changes; secondary infection when the cyst wall is thickened, the lesion area has fine echoes, the cyst has hemorrhage when the echoes are enhanced. 3.Intravenous pyelogram (ivp) can show the extent of cyst compression of renal parenchyma, and can be distinguished from hydronephrosis. 4.CT: It is valuable for those who can not be determined by ultrasound. Typical cysts are spherical, with regular edges, thin and smooth walls, uniform cystic fluid, and the CT value is close to the density of water (-10～+20, which is not strengthened on enhanced scanning). Combined with Ctu, it is possible to determine whether the renal cyst is connected to the collecting system. This CTU is not a complete substitute for IVU, for one thing, there is a time difference, CT is usually over in six minutes, so the contrast will not flow into the small gap. Therefore, the cyst wall, with the collection system close, it is best to line IVU. 5, MRI: MRI, cystic kidney MRI enhancement examination can clarify the nature of renal cysts. V. Do renal cysts need treatment? What are the main treatment methods? 1.Follow-up observation: if the cysts are small (diameter <5cm) and the renal parenchyma has no obvious manifestation of compression, infection, malignancy, hypertension, etc., generally no treatment is needed, and annual rechecking of ultrasound is sufficient. Sclerotherapy: it is suitable for medium-sized renal cysts without complications. Sclerosing agent (such as anhydrous ethanol or tetracycline) is injected after puncture and aspiration of cystic fluid. Although it is economical, simple and safe, it is easy to recur and has been used less frequently. 3.Surgical treatment: the indications for surgical treatment are: (1) those with pain symptoms or psychological pressure; (2) those larger than 4cm or those with compression and obstruction imaging changes (I generally relax to 5cm); (3) those with secondary hemorrhage or suspected cancer. Laparoscopic renal cyst debridement and decompression: it is suitable for the majority of patients with renal cysts; the "roof" of the cyst will be lifted off to prevent the accumulation of cystic fluid. It belongs to minimally invasive surgery and has gradually replaced open surgery as the main surgical method for treating renal cysts. Open nephrectomy for renal cysts: suitable for complicated renal cysts or suspected malignant changes. Nephrectomy: applicable to cysts that are huge, with little normal renal tissue, the affected side of the kidney is no longer functional, and the opposite side of the kidney is sound. Will renal cysts become cystic kidney cancer? When it comes to renal cysts, it is commonly known as "a bag on the waist", and people always "talk about tumor" when they hear something on their body, but in fact, renal cysts are not a tumor disease according to the current medical knowledge, it is categorized as one kind of renal malformation, and it is the most common cystic lesion in the human body. The most common cystic lesions, mostly benign. Will renal cysts become malignant? Does cystic kidney cancer come from malignant cysts? So far, no scientific evidence can be found to answer this question. According to my personal knowledge and experience, cyst is cyst and cystic kidney cancer is cystic kidney cancer, they have nothing to do with each other, if we have to say that there is a relationship between them, it is just like a sheep and a wolf in sheep's skin. How to determine the malignancy of renal cyst? Clinicians can grade renal cysts through ultrasound and CT, which is called "Bosniak grading system". Bosniak type I: Cysts with watery density, thin wall, smooth, no segregation, nodules, calcification; no enhancement. Generally benign. Can be followed up. Bosniak type II: thin-walled cyst, thin fine septations, smaller calcifications, no nodules, no enhancement; dense lesion, but no enhancement. less than 5% malignant possible, requires regular close follow-up. Bosniak type III: thick cystic wall, septations or calcifications with enhancement. 50% malignant, requires surgery. Bosniak type IV: fulfills type III manifestations with nodular foci of enhancement. 80-90% are malignant and require surgery. For grade I-II cysts, observation and follow-up is 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! Eight, the prevention of renal cysts precautions (a) dietary precautions 1, avoid alcohol and beverages: to avoid drinking alcohol, especially white wine, for patients with polycystic kidneys in terms of alcohol and kidney stimulation is too great. It will stimulate polycystic protein activity, accelerate the growth of cysts. 2, avoid eating fungus fermented food: eating such as tofu milk, rotten eggs type of fungus fermented such will not be conducive to controlling the growth rate of cysts. 3, avoid high protein food: protein diet, such as soy, tofu, and other soy products, will increase the body's nitrogen metabolite synthesis, increase renal excretion, is not conducive to the prevention of renal cysts. 4, avoid eating animal offal: animal offal, especially animal liver, even if made into cooked food, a lot of metabolic toxins are still left inside, renal cyst patients taking these will undoubtedly increase the burden on the kidneys, aggravate the condition. (B) other precautions: 1, avoid strenuous physical activity, avoid abdominal kidney trauma. 2, avoid belt too tight (when the kidney enlargement is more obvious), in order to prevent cyst rupture. 3.Control blood pressure: controlling high blood pressure plays a decisive role in protecting renal function. 4.Prevention of urinary tract infection: extra care should be taken in diet, personal hygiene, etc., proper exercise should be taken, and clothes should be increased or decreased at any time according to the weather temperature change to prevent colds and other infections.