Acquired Fanconi's syndrome associated with monoclonal gammopathies

Fanconi's syndrome is a rare complication of the monoclonal gammopathies ch aracterized by diffuse failure in reabsorption at level of the proximal ren al tubule, resulting in glycosuria, generalized aminoaciduria, and hypophos phatemia. It is predominantly associated with monoclonal kappa light chains in the urine. Overt hematologic malignancies, such as multiple myeloma, Wa ldenstrom's macroglobulinemia, or other lymphoproliferative disorders, occu r in one third of patients. The prognosis is good in the absence of overt m alignant disease. Clinical manifestations include slowly progressive renal failure and bone pain secondary to osteomalacia. Treatment consists of supp lementation with phosphorus, calcium, and vitamin D. Chemotherapy may benef it patients with rapidly progressive renal failure or symptomatic malignanc y.