Cadmium-induced osteopathy: clinical and autopsy findings of four patients.

Clinical and autopsy findings of 4 patients with chronic cadmium toxication by peroral uptake of cadmium are reported. Cadmium toxication was liable to occur in multiparous postmenopausal women, and it began with proteinuria, glycosuria, lumbago and bone pain. Then, renal function gradually decreased being accompanied with renal tubulopathy. Autopsy disclosed renal tubulopathy, which consisted of the flattening of the epithelium of proximal convoluted tubules at the peripheral portion and the mild thickening of the tubular basement membrane. There was no primary change in the glomerulus and renal interstitium. Osteomalacia was observed in the vertebrae and several other bones. The degree of osteomalacia was in good agreement with chronic renal tubular dysfunction. A decrease of the estrogen content, in addition to renal tubulopathy due to biological saturation of cadmium, seems to play an important role in the pathogenesis of cadmium-induced osteomalacia.