HIGH-RESOLUTION RADIOGRAPHY OF CADAVERIC KIDNEYS - UNRAVELING THE MYSTERY OF RANDALLS PLAQUE-FORMATION

Purpose: We used high resolution radiography to identify and character ize Randall's plaques in cadaveric kidneys. Materials and Methods: A t otal of 50 consecutive sets of cadaveric kidneys was fixed, bivalved a nd imaged with micro-focal spot magnification radiography. Papillary c alcifications were identified, localized and processed for light micro scopy. Special immunohistochemical stains were implemented to aid loca lization of ectopic calcifications. Patient medical records and autops y results were retrospectively evaluated and correlated with radiograp hic papillary calcifications. Results: Of the 92 renal units with comp lete data 52 (57%) had radiographic evidence of renal medullary calcif ications consistent with Randall's plaques. Unlike the original descri ption of this condition, calcifications extended deep into the papilla . A history of hypertension was the only clinical parameter correlatin g with papillary calcifications. Calcium deposition was localized to t he basement membrane of collecting tubules and vasa recta, and papilla ry interstitium. Conclusions: Randall's plaques are not merely subepit helial deposits. Rather, they appear to extend deep within the papilla , and are intimately associated with collecting tubules and vasa recta . An association between papillary calcifications and urinary stone fo rmation has yet to be proved but is under investigation.