A couple of days ago a friend was found to have a spongy kidney in his medical checkup, at first he was quite curious, a sponge like kidney? In order to figure out what exactly is sponge kidney, the result of their own online research, sleep and food …… 1.What is a sponge kidney? Sponge kidney, also known as medullary sponge kidney, is a congenital disease in which the collecting duct in the medullary cone of the kidney is shuttle-shaped or cystic expansion, the appearance of the bulk of the specimen like a sponge, most of the small capsule and the renal tubules or renal pelvis connected. It often develops at the age of 40 to 50 years, and 70% have bilateral renal onset. The prognosis is good, and renal insufficiency rarely occurs. It is common in males, and there is usually no family history. 2.How does spongy kidney form? The disease is associated with autosomal recessive disorders or autosomal dominant inheritance, and the cause of its development is unknown. Infection or obstruction has been proposed as the cause of the disease, and infection is now considered to be secondary. Many scholars see the disease as a congenital malformation of the renal medulla. 3.Clinical manifestations of sponge kidney Because the development of the disease is very slow, so there are no clinical symptoms in the early stage. The common symptoms are recurrent hematuria, urinary tract infection symptoms, back pain, renal colic and history of stone removal, and individual manifestation of painless meatus hematuria. The clinical symptoms are due to the retention of urine in the dilated capsule secondary to infection, bleeding or stones. Patients often have urinary tract infections, and when co-infections are present, pusuria may occur. Extensive cystic lesions may present with decreased urinary concentration and acidification, increased urinary calcium excretion, a good prognosis, and rarely renal failure. In advanced stages, anemia, sodium loss and azotemia may occur. 4, spongy kidney imaging manifestations (1) MRI scan: kidney cone area radial, streak-like distribution of abnormal signals of varying sizes of cysts with clear borders. (2) KUB plain radiograph: it shows clustered, radiolucent or plural corn-like arrangement of calcifications and stones in the renal parenchyma. (3) IVU (urography): shows normal pelvis and calyces or widened calyces with protruding enlarged cups, and the contrast is seen on the outside as fan-shaped, petal-shaped, grape bunch-shaped and mosaic-shaped shadows in the enlarged renal tubules, with no connection between the cystic cavities. 5.Diagnostic points of spongy kidney (1) Most patients have no symptoms and normal laboratory tests. (2) If complicated by infection and stones, hematuria, colic and urinary tract irritation may appear. (3) X-ray manifestations: normal or slightly enlarged kidney shadow, multiple round, round-like or irregular-shaped stones in the renal parenchyma on both sides or unilaterally, with a diameter of 2-5 mm, in a cluster or fan-shaped distribution. (4) CT: scattered or dense multiple stones in one or more renal cones, with petal-like or fan-shaped distribution. (5) Excretory urography: normal or mildly enlarged kidney size, radiolucent streak-like or bouquet-like distribution of contrast in the renal papillae or dilated collecting ducts, and generally normal renal function. 6. Differential diagnosis of spongy kidney (1) Multiple kidney stones: there may be symptoms such as back pain, renal colic, hematuria and history of stone removal. On KUB plain film, it is shown as multiple hyperdense shadows in the kidney, but urography shows that the stones are located in the renal pelvis or calyces, without the characteristic distribution of spongy kidney, mostly accompanied by dilated hydronephrosis in the renal pelvis or calyces. (2) Renal tuberculosis: there may be symptoms of back pain and hematuria. KUB plain film and ultrasound can see multiple irregular calcified foci in the renal parenchyma. However, they are mostly accompanied by systemic symptoms of tuberculosis and obvious urinary tract irritation. Urography shows destruction of the renal pelvis and calyces and irregular narrowing or atresia of the ureters. Antacid bacilli found in the urine can clarify the diagnosis. 7.Treatment of sponge kidney There is no special treatment for this disease, mainly for complications. Cases without special clinical symptoms and complications do not need special treatment and can be followed up regularly. (1) General treatment: sodium supplementation, severe hematuria requires blood transfusion to correct anemia. (2) Kidney stone treatment: It is not yet possible to prevent the formation of cystic stones. One should drink more water and keep the daily urine volume over 2000ml to reduce calcium salt deposition. Patients with hypercalciuria should take long-term thiazide diuretics; patients with normal urinary calcium stones should take oral phosphate drugs. (3) Prevention and treatment of infection: appropriate use of sensitive antibiotics. (4) Surgical treatment: Since the lesions are often bilateral, surgical treatment is rarely used. If unilateral or segmental lesions are diagnosed, nephrectomy or partial nephrectomy can be considered when the renal function of the opposite side is normal. 8, sponge kidney dietary health and preventive care (1) diet: specific dietary recommendations need to consult a doctor according to the symptoms, a reasonable diet, to ensure a comprehensive and balanced nutrition. Eat more vegetables and fruits, eat a light diet, quit smoking and alcohol, and eat less greasy, fishy, spicy and stimulating food. (2) Prevention: Patients with this disease are prone to urinary tract infection, especially in women. If pyelonephritis or cyst infection is induced, the pain in the kidney area will be aggravated with obvious fever, hematuria and purulent urine, and serious cases may lead to urinary tract sepsis. Therefore, active symptomatic and supportive treatment is necessary to control urinary tract infections and prevent the occurrence of complications such as kidney stones.