Lynn D. Cornell, MD

Nephrocalcinosis, with purple-staining calcium phosphate image deposits in the interstitium, is associated with interstitial inflammation in this case.

A von Kossa stain reveals tubular basement membrane image and interstitial calcification image.



  • Deposition of abundant calcium phosphate precipitates within renal tubules, tubular basement membrane, and interstitium

  • “Nephrocalcinosis” usually refers to calcium phosphate deposits in setting of hypercalcemia

    • Calcium oxalate deposits in other conditions (e.g., primary hyperoxaluria, usually termed “oxalosis”)


Calcium Precipitation Within Kidney

  • Increased urinary concentration of calcium and phosphate that allows for precipitation

  • Almost all calcium (98%) filtered by glomerulus is reabsorbed by tubule

  • Randall plaques (calcium deposits at or near papillary tip) may be initial site of calcification, at least in some types of nephrocalcinosis

    • Randall plaques show deposits in interstitium, tubular basement membranes, and tubular lumens

Hypercalcemia Due to Various Conditions

  • Nephrocalcinosis usually in setting of chronic hypercalcemia

  • Sarcoidosis

  • Hypercalcemia of malignancy

  • Milk-alkali syndrome

  • Hypervitaminosis A or D

  • Hyperparathyroidism (primary)

Inherited Tubulopathies

  • Dent disease, cystinosis, and others



  • Age

    • Childhood through older adulthood

    • Neonates, especially those receiving loop diuretics


Jul 7, 2016 | Posted by in PATHOLOGY & LABORATORY MEDICINE | Comments Off on Nephrocalcinosis
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