Nephrocalcinosis

Know the causes of nephrocalcinosis

• Caused by diseases characterized by hypercalcemia

• HyperPTH

• Multiple myeloma

• Vitamin D intoxication

• Metastatic bone disease

• Excess Ca intake

Know that functional defects and morphologic changes of the kidney w/ nephrocalcinosis

• Earliest functional defect is inability to make a concentrated urine

• Other tubular defects, such as tubular acidosis and salt-losing nephritis, may also occur

• Further damage produces a slowly progressive renal insufficiency, which may also be due to subsequent Ca stones and secondary pyelonephritis

• Morphologically, the first changes are intracellular – mitochondrial distortion and cell injury due to deposits w/in cytoplasm, mitochondria, and BM

• Cellular debris  tubular lumen obstruction  obstructive atrophy of nephrons  interstitial fibrosis and nonspecific chronic inflammation.

• Atrophy of entire cortical areas accounts for alternating areas of normal / scarred parenchyma

Category: Pathology Notes