Renal cyst
Introduction
Introduction to renal cyst A renal cyst (renalcyst, cystofkidney), or a cystic disease of the kidney, as the name suggests, is a general term for cystic lesions in the kidney that are not connected to the outside world. Common renal cysts such as simple renal cysts, pararenal cysts, and polycystic kidneys. With the popularization of physical examination and the extensive application of B-ultrasound and CT, the detection rate of renal cyst disease has been significantly improved, and it has become a clinically common kidney disease. Some kidney tumors (such as cystic renal cell carcinoma) may have a cystic structure due to the formation of necrosis and cavities inside the tumor, which should be differentiated from renal cysts. basic knowledge The proportion of illness: 0.001% (incidence rate of more than 50% in people over 50 years old) Susceptible people: no specific population Mode of infection: non-infectious Complications: proteinuria hypertension
Cause
Cause of renal cyst
Whether a simple renal cyst is congenital or acquired is unclear. Its origin may be similar to polycystic kidney disease, but only to a different extent. On the other hand, by causing tubular obstruction and ischemia, Animals can develop simple renal cysts, which suggests that the lesion can also be acquired. With the increase of cysts, the base pressure can damage the renal parenchyma, but it will not damage the kidney function. The site of the cyst can just be pressed into the ureter, causing progressive hydronephrosis, which can be followed by concomitant infection. Feiner, Katz and Gallo noted in 1980 that acquired renal cyst disease is common in long-term dialysis patients, Kessel and In 1981, Tynes observed two cases of renal cysts that resolved spontaneously.
Prevention
Kidney cyst prevention
Cold is one of the most important factors leading to kidney damage in patients with kidney disease. Clinically, patients with chronic nephritis may have a recurrence of the disease on the same day or the next day, and the kidneys will intensify the injury. Therefore, we must pay attention to preventing colds in daily life. If we have a cold, we should treat them in time to avoid deterioration.
Excessive intake of protein can lead to the onset and recurrence of chronic kidney disease. Therefore, daily life should be controlled by diet, and more attention should be paid to Chinese New Year.
Anemia, high blood pressure, edema, and backache may all be precursors to kidney disease. Be aware of these symptoms.
Strengthen exercise, strengthen blood circulation in the kidneys, help damage repair, and prevent glomerular sclerosis.
Complication
Renal cyst complications Complications, proteinuria, hypertension
Spontaneous infections are rare in simple renal cysts, and once they occur, they are difficult to differentiate from renal pelvis. Sometimes there is bleeding in the cyst. When it happens suddenly, it can cause severe pain. The bleeding can come from the cancer on the wall of the cyst. When the cyst is located in the lower pole of the kidney and close to the ureter, it can aggravate hydronephrosis, and the pressure of the urine on the renal pelvis can cause back pain. This obstruction can also cause infection in the kidneys.
Kidney cysts can also cause some other diseases
1. Proteinuria: The general amount is not much, and it will not exceed 2 grams in 24 hours, so no nephrotic syndrome will occur.
2. Hypertension: The solid cyst compresses the kidney, causing renal ischemia, causing increased renin secretion and causing hypertension. When kidney function is normal, more than 50% of patients have hypertension, and the incidence of hypertension is higher when renal dysfunction occurs.
3. Renal dysfunction: due to cyst compression and occupying, the normal kidney tissue is significantly reduced, and renal function is progressively reduced.
Symptom
Renal cyst symptoms Common symptoms Male abdominal pain, kidney ischemia, dull pain, proteinuria, abdominal mass, cyst, hematuria
(1) Waist, abdominal discomfort or pain: pain is characterized by dull pain, dull pain, fixed on one or both sides, radiating to the lower and lower back;
(2) hematuria: can be expressed as microscopic hematuria or gross hematuria;
(3) Abdominal mass: sometimes the main reason for patients to see a doctor, 60-80% can reach the enlarged kidney, the larger the kidney, the worse the kidney function;
(4) proteinuria: the general amount is not much, 24 hours urine will not exceed 2 grams, so no kidney disease syndrome will occur;
(5) Hypertension: The cyst compresses the kidney, causing renal ischemia, causing increased renin secretion and causing hypertension.
Examine
Renal cyst examination
First, the basic inspection
(1) Examination of urine The urine is normal. If the renal parenchyma is compressed in the capsule or there is an intracapsular infection, a small amount of red blood cells and white blood cells may appear in the urine.
(2) B-ultrasound can understand the number, size, and wall of the cyst, and can be differentiated from the solid mass of the kidney. It is the preferred method of examination. The typical B-ultrasound shows no echo in the lesion, the wall is smooth, and the boundary is smooth. Clearly; when the wall shows irregular echo or limited echo enhancement, it should be vigilant; the secondary wall is thickened, the lesion has a fine echo, and the echo is enhanced when there is bleeding in the capsule. Multiple cysts should be distinguished from multiple atrial cysts and polycystic kidneys.
(3) Intravenous pyelography (ivp) can show the degree of cystic compression of renal parenchyma and can be differentiated from hydronephrosis.
Second, further inspection
CT, the B-ultrasound can not be determined to be valuable, cysts with bleeding, infection, malignant transformation, showing heterogeneity, CT value increases, when CT shows cyst characteristics, you can not do cyst puncture.
Diagnosis
Diagnosis and differentiation of renal cyst
diagnosis
Adult kidney cyst
Adult kidney cyst is a congenital hereditary disease. The kidney parenchyma is filled with round cysts of varying sizes and sizes that are not connected to the outside. The capsule contains liquid, which is invisible to the naked eye. Large can be several centimeters. Therefore, it is called polycystic kidney disease. It is characterized by increased nocturia, low back pain, high blood pressure, etc. Urine tests have hematuria, a small amount of proteinuria, and often develop slowly into chronic renal failure. 10% have kidney stones and 30% have polycystic liver disease. Experienced doctors can confirm the diagnosis with B-ultrasound and intravenous pyelography.
Simple renal cyst
A simple renal cyst may be a congenital anomaly. It is a unilateral or bilateral kidney and has one or several small and inconsistent circular cavities that are not connected to the outside world. Most of them are unilateral, so it is called a simple renal cyst. . The incidence can be increased with age, and people over 50 years old can do B-ultrasound, and 50% can find this cyst. With B ultrasound, CT can be diagnosed.
Acquired renal cyst
Acquired renal cysts occur mainly after uremia or dialysis treatment. Not related to age, but related to the time of hemodialysis. There is no renal cyst in the kidney. According to the literature, most patients will have cysts when the dialysis time is more than 3 years. It has at least 4 cysts in one kidney, and the diameter is usually 2 to 3 cm. Some cysts can be infected or even cancerous. B-ultrasound or CT examination can confirm the diagnosis.
Differential diagnosis
(1) Kidney cancer: It is a space-occupying lesion, but it is prone to occur in the deep part, which causes more obvious pyelectus curvature. The hematuria is common, while the cyst is not seen. When the renal parenchyma tumor is pressed on the psoas muscle, the abdomen is flat. The edge of the muscle is not visible on the film, and the cyst is still visible. There is evidence of metastasis (such as weight loss, fatigue, swelling on the clavicle, chest radiograph showing metastatic nodules), polycythemia, high calcium Hyperemia and erythrocyte sedimentation rate are all suggestive of cancer. It should be remembered that the cyst wall will also undergo cancerous changes. If the renal vein is blocked by cancer, excretory urography is unclear or not developed, and ultrasound images and CT is always used for differential diagnosis. Angiography and renal tomography can show that in a tumor with abundant blood vessels, there is a contrast-intensive "pond", and the density of the cyst is not affected. It is proved to be Before other diseases, it is wise to assume all kidney-occupying lesions as cancer.
(2) Polycystic kidney disease: As shown by urography, the disease is almost always bilateral, and the pervasive renal pelvis and renal pelvis are distorted. The simple renal cyst is mostly isolated, Polycystic kidney disease is often accompanied by renal impairment and high blood pressure, while renal cysts are not.
(3) renal pelvis: This disease is rare. When collecting medical history, it can be found that there is a history of skin infection in the weeks before the fever and local pain. Urinary angiography shows that the lesion is similar to cyst and tumor, but due to the influence of periarteritis, The kidney contour and the lumbar muscles are blurred. At this time, the kidneys are more fixed, and the kidney position can be confirmed when the patient is supine and erect. The angiography can show a bloodless lesion, gallium-67 scan. It can show the inflammatory nature of the lesion, but the infected simple cyst can also have a similar performance.
(4) hydronephrosis: symptoms and signs can be consistent with the performance of simple renal cysts, but urography is quite different, cysts cause kidney deformation, and hydronephrosis is due to obstruction caused by renal pelvis and renal pelvis The expansion of acute or subacute hydronephrosis often results in more limited pain due to increased intra-renal pressure and is complicated by infection.
(5) Extrarenal tumors (such as adrenal glands, mixed retroperitoneal sarcoma): can shift the kidneys, but rarely invade the kidneys and deform the renal pelvis.
(6) Can echinococcosis: When the cyst is not connected with the renal pelvis, it is difficult to distinguish it from simple renal cyst. Because there is no worm and its larva in the urine, the renal hydatid cyst is often found on the X-ray examination. It is helpful to diagnose the disease with calcification and skin sensitivity tests.
