[Durgical](https://durgical.com/en/) › [DurgiPedia](https://durgical.com/en/durgipedia/) › [General pathology](https://durgical.com/en/general-pathology/) › [Kidney](https://durgical.com/en/general-pathology/areas/kidney/) › Crystal nephropathies and nephrocalcinosis # Crystal nephropathies and nephrocalcinosis - Lesion Uric acid, calcium and oxalate can precipitate in tubules and interstitium, blocking them or causing chronic scarring. Updated Nov 12, 2026 ## Key points - Acute urate nephropathy: uric acid crystals block collecting ducts after chemotherapy of leukemias and lymphomas. - Chronic urate nephropathy: needle-shaped urate crystals in tubules and interstitium surrounded by giant cells (tophi). - Nephrocalcinosis: calcium phosphate in tubular cells, basement membranes and interstitium; polyuria from lost concentrating power. - Oxalate: birefringent calcium oxalate crystals; primary hyperoxaluria, enteric hyperoxaluria, ethylene glycol. - All of them favour stones, which add obstruction and infection. ## What it is Crystals injure the kidney in three ways: by blocking tubules suddenly, by depositing in the interstitium and inciting chronic inflammation, and by forming stones. Acute urate nephropathy follows massive cell death in tumour lysis; chronic urate nephropathy is seen in long-standing gout. Hypercalcemia from hyperparathyroidism, myeloma, sarcoidosis, vitamin D excess or bone metastases causes calcium deposits (nephrocalcinosis) and concentrating defects. Oxalate deposits come from primary hyperoxaluria, gut fat malabsorption and ethylene glycol. ## Structure - Urate crystals dissolve in aqueous fixatives and leave clefts; alcohol fixation preserves them for polarized light. - Tophi: crystal clusters surrounded by macrophages, foreign-body giant cells, lymphocytes and fibrosis. - Calcium deposits stain dark purple on H&E and black with von Kossa. - Calcium oxalate crystals are fan- or sheaf-shaped and strongly birefringent. ## Crystal nephropathies | Disorder | Setting | Kidney lesion | | --- | --- | --- | | [Acute urate nephropathy](https://durgical.com/en/conditions/tumour-lysis-syndrome/) | Tumour lysis after chemotherapy | Crystals obstruct collecting ducts; acute kidney injury | | [Chronic urate nephropathy](https://durgical.com/en/conditions/gout/) | Long-standing gout | Medullary tophi, chronic interstitial nephritis | | [Nephrocalcinosis](https://durgical.com/en/conditions/hypercalcaemia/) | Hypercalcemia (hyperparathyroidism, myeloma, sarcoidosis, vitamin D excess) | Calcium in tubules and interstitium, polyuria, stones | | [Oxalate nephropathy](https://durgical.com/en/conditions/primary-hyperoxaluria/) | Primary hyperoxaluria, enteric hyperoxaluria, ethylene glycol | Oxalate crystals in tubules, acute or chronic injury | ## Clinical notes - Prevention of tumour lysis (hydration and lowering uric acid) protects the kidney during chemotherapy of bulky tumours. - Hypercalcemia causes polyuria and thirst because calcium blunts the response to ADH. ## Memory aid Salt that won't stay dissolved: urate after lysis, calcium when bones or glands overflow, oxalate when fat or antifreeze is the source. ## Test yourself Think of the answer, then tap the question to see it. ## What causes acute urate nephropathy? Massive release of uric acid after rapid cell death, typically during chemotherapy of leukemia or lymphoma, which precipitates in collecting ducts. ## Why does nephrocalcinosis cause polyuria? Calcium injures tubules and blunts the collecting duct response to ADH, so the urine cannot be concentrated. ## What crystals are found in ethylene glycol poisoning? Calcium oxalate crystals in tubules and in the urine. [Add to my cards (3)](https://durgical.app/estudiar/?add=/en/general-pathology/crystal-nephropathies-and-nephrocalcinosis/) [More Pathology questions →](https://durgical.com/en/practice/?f=pathology) ## Elsewhere in DurgiPedia - [Pathologic calcification: dystrophic vs metastatic](https://durgical.com/en/general-pathology/pathologic-calcification-dystrophic-vs-metastatic/) - [Uric acid](https://durgical.com/en/biochemistry/molecules/uric-acid/) - [Purine degradation and salvage](https://durgical.com/en/biochemistry/pathways/purine-degradation-and-salvage/) ## Connections ## Related 4 - [Kidney stones](https://durgical.com/en/general-pathology/kidney-stones/) - [The kidney in plasma cell disorders](https://durgical.com/en/general-pathology/the-kidney-in-plasma-cell-disorders/) - [Tubulointerstitial nephritis: acute drug-induced vs chronic forms](https://durgical.com/en/general-pathology/tubulointerstitial-nephritis-acute-drug-induced-vs-chronic-forms/) - [Pathologic calcification: dystrophic vs metastatic](https://durgical.com/en/general-pathology/pathologic-calcification-dystrophic-vs-metastatic/) ## Related conditions 8 - [Gout](https://durgical.com/en/conditions/gout/) - [Tumour lysis syndrome](https://durgical.com/en/conditions/tumour-lysis-syndrome/) - [Hypercalcaemia](https://durgical.com/en/conditions/hypercalcaemia/) - [Primary hyperparathyroidism](https://durgical.com/en/conditions/primary-hyperparathyroidism/) - [Sarcoidosis](https://durgical.com/en/conditions/sarcoidosis/) - [Primary hyperoxaluria](https://durgical.com/en/conditions/primary-hyperoxaluria/) - [Lesch-Nyhan syndrome](https://durgical.com/en/conditions/lesch-nyhan-syndrome/) - [Hypercalcaemia of malignancy](https://durgical.com/en/conditions/hypercalcaemia-of-malignancy/) [← All of general pathology](https://durgical.com/en/general-pathology/) Educational content on the mechanisms of disease; not a diagnostic or treatment guide and no substitute for a health professional's advice. No doses are given. Sources: [Renal Calculi, Nephrolithiasis](https://www.ncbi.nlm.nih.gov/books/NBK442014/) (StatPearls (NCBI Bookshelf), 2024). ## **Spotted a mistake?** We are always improving for the community. Tell us what is wrong and our team will review it. Report a mistake Representative model, for educational purposes only. --- Source: https://durgical.com/en/general-pathology/crystal-nephropathies-and-nephrocalcinosis/ License: CC BY 4.0 (https://creativecommons.org/licenses/by/4.0/). Cite as: DurgiPedia (durgical.com), https://durgical.com/en/general-pathology/crystal-nephropathies-and-nephrocalcinosis/