Skip to Main Content

We have a new app!

Take the Access library with you wherever you go—easy access to books, videos, images, podcasts, personalized features, and more.

Download the Access App here: iOS and Android. Learn more here!

For further information, see CMDT Part 22-28: Medullary Sponge Kidney

Key Features

  • Affects < 1% of the general population

  • Present at birth and not usually diagnosed until the fourth or fifth decade

  • Thought to occur due to disruption of the ureteric bud-metanephric mesenchyme interface, often resulting from autosomal dominant mutations in genes responsible for urogenital development; this is associated with medullary cysts that are diffuse, giving a "Swiss cheese" appearance

  • Kidneys have a marked irregular enlargement of the medullary and interpapillary collecting ducts

Clinical Findings

  • Nephrolithiasis is most common clinical presentation

  • Other presentations may include hematuria (either gross or microscopic) or recurrent urinary tract infections

  • Common abnormalities are a decreased urinary concentrating ability and nephrocalcinosis

  • Less common is incomplete type I distal renal tubular acidosis


  • CT shows

    • Cystic dilatation of the distal collecting tubules

    • A striated appearance in this area

    • Calcifications in the renal collecting system


  • Supportive; aimed at underlying abnormalities such as nephrolithiasis and acidosis

  • Adequate fluid intake (2 L/day) helps reduce risk of stone formation

  • If hypercalciuria is present, thiazide diuretics are recommended because they decrease calcium excretion

  • Alkali therapy is recommended if renal tubular acidosis is present

Pop-up div Successfully Displayed

This div only appears when the trigger link is hovered over. Otherwise it is hidden from view.