Rare, developmental abnormality characterised by ectatic (dilatory) or cystic malformations in the medullary collecting ducts of the kidney resulting in medullary cysts.
Most patients are asymptomatic and the condition may be diagnosed based on incidental findings following radiological investigation for other reasons.
May be present in 3% to 25% of patients with renal stones.
May present with flank pain, recurrent UTIs, haematuria (gross and microscopic), nephrolithiasis, and nephrocalcinosis.
No specific treatment, and for many patients the condition is normally benign. For patients with symptoms, treatment focuses on treating UTI, removing kidney stones, and preventing recurrent infections and stones.
Medullary sponge kidney (MSK) is a rare, developmental abnormality that can occur in 1 or both kidneys, characterised by ectatic or cystic malformations in the medullary collecting ducts. The medullary cysts can range from 1 to 7 mm in diameter. Their presence gives the medulla a sponge-like appearance. Most patients are asymptomatic.
Associate Professor of Medicine
Clinical Director of Nephrology
Johns Hopkins University School of Medicine
MJC declares that he has no competing interests.
Division of Nephrology
New York University School of Medicine
New York VA Medical Center
DSG declares that he has no competing interests.
Dr Michael J. Choi and Dr David S. Goldfarb would like to gratefully acknowledge Dr Amaka Edeani, a previous contributor to this monograph. AE declares that she has no competing interests.
Internal Medicine Physician
UT Southwestern Medical Center
KS declares that he has no competing interests.
Assistant Professor of Medicine
Harvard Medical School
Brigham and Women's Hospital
ENT declares that he has no competing interests.
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