From the Research
Medullary sponge kidney (MSK) is a rare congenital malformation of the distal nephron where cystic dilatation is appreciable in the collecting ducts and renal papillae, typically presenting with urinary tract infections, nephrolithiasis, and nephrocalcinosis 1.
Definition and Pathophysiology
Medullary sponge kidney is characterized by the dilation of the collecting ducts in the renal medulla, giving the kidney a sponge-like appearance on imaging. This condition is thought to arise from a malfunction within neurotrophic factor and tyrosine kinase interactions 1. The main complications of MSK include kidney stones, urinary tract infections, and hematuria (blood in urine).
Clinical Presentation and Diagnosis
The presentation and prognosis of MSK are usually indolent, but can include symptoms such as urinary tract infections, nephrolithiasis, and nephrocalcinosis 1. Diagnosis of MSK can be difficult due to the lack of specific symptoms and the fact that many cases are asymptomatic. Intra-venous urogram (IVU) remains the current gold standard to diagnose MSK, but other methods such as endoscopy and Multi-detector computed tomography (MDCT) are being used 1.
Treatment and Management
Treatment for MSK focuses on managing symptoms rather than curing the underlying condition, and may include the application of potassium citrate compounds, prophylactic water and diet control, surgical intervention or lithotripsy for removal of symptomatic kidney stones 1. Patients should increase fluid intake to 2-3 liters daily to dilute urine and prevent stone formation. Thiazide diuretics like hydrochlorothiazide may be prescribed to reduce calcium excretion in those with calcium stones. Potassium citrate can help alkalize urine and prevent stone formation. Antibiotics are used to treat urinary tract infections when they occur. Pain management during stone passage may require medications like ibuprofen or, in severe cases, narcotic analgesics.
Prognosis and Quality of Life
Despite the complications associated with MSK, most people with the condition maintain normal kidney function throughout their lives, though regular monitoring by a nephrologist is recommended 1. With proper management and treatment, patients with MSK can lead active and normal lives, with a good quality of life. However, it is essential to be aware of the potential complications and to seek medical attention if symptoms persist or worsen over time.