A patient with Fanconi's syndrome, myeloma IgA kappa and cystoplasmic crystals

A 45 year old man with IgA-Kappa myeloma had adult Fanconi Syndrome. Examin ation of renal biopsy revealed lesions in proximal tubules without glomerul ar lesions and without intratubular casts. By electron microscopy cytoplasm ic crystalline inclusions were observed in renal proximal tubular epitheliu m. Increased plasma cells (28%) in bone marrow aspiration also contained cr ystalline inclusions. The treatment of myeloma produced partial remission o f proliferative disease and Fanconi syndrome. We discuss the pathogenesis o f Fanconi syndrome induced by light chains as well as the composition of cr ystalline deposits and the effects of treatment on Fanconi Syndrome.