Medullary Sponge Kidney
An unusual association of contralateral congenital small kidney, reduced renal function and hyperparathyroidism in sponge kidney patients: on the track of the molecular basis. (1/10)
Of unknown pathogenesis, sponge kidney (SK) is variably associated with nephrocalcinosis, stones, nephronic tubule dysfunctions and precalyceal duct cysts. Amongst 72 unrelated renal SK patients with renal stone disease, we detected one with unilateral bifid renal pelvis and six with unilateral small kidneys (longitudinal diameter difference >15%). Secondary causes of small kidney were excluded. Of the seven cases, four had reduced renal function (67 vs 7% in the entire cohort), and three developed hyperparathyroidism during follow-up (43 vs 4%). The pathogenesis of SK ought to explain why anatomical structures of different embryological origin are involved (the precalyceal and collecting ducts and the nephron) and why there is frequent association with hyperparathyroidism. In embryogenesis, the metanephric blastema synthesizes the chemotactic glial-derived neurotrophic factor (GDNF) to prompt the ureteric bud to branch off from Wolff's mesonephric duct, and to approach and invade the blastema. The bud's tip expresses the GDNF receptor (RET). RET-GDNF binding is crucial not only for the correct formation of ureters and collecting ducts (both of Wolffian origin), but also for nephrogenesis. We advance the hypothesis that SK results from a disruption in the ureteric bud-metanephric blastema interface, possibly due to one or more mutations or polymorphisms of RET or GDNF genes. This would explain: the concurrent alterations in precalyceal ducts and the functional defects in the nephron, the occasional association with size and the functional asymmetry between the two kidneys, some degree of renal dysplasia causing the reduction in the glomerular filtration rate and (given the role of RET in parathyroid cell proliferation) the association with hyperparathyroidism. (+info)Medullary sponge kidney in a 10-year-old Shih Tzu dog. (2/10)
Medullary sponge kidney was diagnosed in a 10-year-old male Shih Tzu dog with a long history of hyposthenuria, but with no other findings indicating renal failure or hormonal aberration. At the dog's death from heart failure, an autopsy was performed. On gross morphology, bilateral kidneys were normal size and had many cysts ranging from the corticomedullary junction to renal papillae. Histopathologic findings showed that almost all of the cysts were lined by monolayered or multilayered and columnar or cuboidal epithelium with chilium similar to epididymis. Immunohistochemically, all of these cells were strongly positive for AE1/AE3 and negative for vimentin. Many of these cells were positive for cytokeratin 7 (CK7), and only a few cells were positive for desmin. The results of staining are the same as those for epithelium of the collecting duct of normal canine kidney. This is the first report of this pathologic entity in the canine kidney. (+info)Medullary sponge kidney associated with primary distal renal tubular acidosis and mutations of the H+-ATPase genes. (3/10)
(+info)Bone disease in medullary sponge kidney and effect of potassium citrate treatment. (4/10)
(+info)Identification of GDNF gene sequence variations in patients with medullary sponge kidney disease. (5/10)
(+info)Long-term treatment with potassium citrate and renal stones in medullary sponge kidney. (6/10)
(+info)Nephrocalcinosis: re-defined in the era of endourology. (7/10)
(+info)MR imaging of focal medullary sponge kidney: case report. (8/10)
We present a case of focal medullary sponge kidney (MSK) that mimicked a renal tumor. Evaluation of a patient with history of macrohematuria revealed a left renal mass of 3-cm diameter. T(1)-weighted magnetic resonance (MR) images revealed a mass of mixed intensity protruding toward the renal sinus. On fat-saturated T(2)-weighted MR images, the lesion's remarkable hyperintensity suggested the presence of an aggregation of tiny cysts. On diffusion-weighted MR images, the mass also demonstrated high intensity, and its apparent diffusion coefficient was partly decreased (1.12 x 10(-3) mm(2)/s). On computed tomography, precontrast images revealed no calcification in the mass. Although slight enhancement was seen in the corticomedullary phase, thick and dense streaks of contrast radiating peripherally were identified in the mass in the excretory phase. Focal MSK was diagnosed. We discuss the potential of MR imaging for diagnosing focal MSK. (+info)Medullary sponge kidney (MSK) is a congenital kidney disorder characterized by abnormal dilations of the collecting ducts within the medulla of one or both kidneys. These dilations give the appearance of a "sponge-like" structure, hence the name of the condition.
In MSK, the affected collecting ducts become filled with small cysts or sacs that can trap calcium and other minerals, leading to the formation of recurring kidney stones and chronic kidney disease in some cases. The disorder can also cause urinary tract infections (UTIs) and hematuria (blood in the urine).
MSK is usually asymptomatic and often discovered incidentally during imaging studies performed for other reasons. However, when symptoms do occur, they may include recurrent kidney stones, flank pain, UTIs, or hematuria. The exact cause of MSK remains unclear, but it appears to have a genetic component, as it can be associated with certain inherited syndromes such as Tuberous Sclerosis Complex and Ehlers-Danlos syndrome.
MSK is typically managed through preventative measures aimed at reducing the risk of kidney stone formation, such as increasing fluid intake, maintaining a healthy diet, and taking medications to lower urinary calcium levels if necessary. In some cases, surgery may be required to remove large or recurrent stones or to treat complications associated with the disorder.
Potassium citrate is a medication and dietary supplement that contains potassium and citrate. Medically, it is used to treat and prevent kidney stones, as well as to manage metabolic acidosis in people with chronic kidney disease. Potassium citrate works by increasing the pH of urine, making it less acidic, which can help to dissolve certain types of kidney stones and prevent new ones from forming. It is also used as an alkalizing agent in the treatment of various conditions that cause acidosis.
In addition to its medical uses, potassium citrate is also found naturally in some fruits and vegetables, such as oranges, grapefruits, lemons, limes, and spinach. It is often used as a food additive and preservative, and can be found in a variety of processed foods and beverages.
It's important to note that taking too much potassium citrate can lead to high levels of potassium in the blood, which can be dangerous. Therefore, it is important to follow the dosage instructions carefully and talk to your doctor before taking this medication if you have any medical conditions or are taking any other medications.