title: Renal cholesterol granulomas: identification and morphological pattern of development.
abstract: Cholesterol granulomas are infrequent and rarely described renal lesions occurring usually in the interstitium, characterized by clusters of foreign body giant cells containing ingested cholesterol crystals. Over a seven-year period, we observed them in 5 of 789 (0.6%) renal biopsies from patients with nephrotic syndrome of varying glomerulopathies. Four patients had renal insufficiency at the time of biopsy, while the fifth developed it within three months. To define the lesions we studied the morphogenesis of cholesterol granulomas by light and electron microscopy. Initially small cholesterol crystals formed in tubular epithelium; the crystals enlarged and were released into tubular lumina where they elongated or were passed in the urine. Further luminal growth caused the crystals to become lodged at some point in the nephron, distort and destroy tubule cells, and pierce through basement membranes with subsequent exposure to interstitial monocytes and formation of granulomas. It is likely these morphological abnormalities evolve from lipid disturbances in the nephrotic syndrome.
mesh_terms: D000328:Adult; D000368:Aged; D001706:Biopsy; D002784:Cholesterol / Q000032:analysis*; D005260:Female; D006099:Granuloma / Q000150:complications / Q000473:pathology*; D006801:Humans; D007668:Kidney / Q000648:ultrastructure; D007674:Kidney Diseases / Q000150:complications / Q000473:pathology*; D008297:Male; D008854:Microscopy, Electron; D009404:Nephrotic Syndrome / Q000150:complications / Q000473:pathology
chemical_list: D002784:Cholesterol