A single-center case series of eight patients with the rare plasma cell dyscrasia of acquired Fanconi syndrome secondary to monoclonal gammopathy.

Acquired Fanconi syndrome (FS) is a rare presentation of monoclonal gammopathy. We retrospectively summarized the cases of eight patients with FS secondary to monoclonal gammopathy at Peking Union Medical College Hospital (PUMCH) from January 2007 to April 2014. All patients had generalized or partial impairment of proximal renal tubular function. Six patients were diagnosed with monoclonal gammopathy of undetermined significance (MGUS), and two were diagnosed with multiple myeloma (MM). Although chemotherapy was administered to the two patients with MM and to one patient with MGUS, decreased paraprotein levels did not lead to improvements in metabolic abnormalities. All patients received continuous supplementation with deficient nutrients, leading to marked remission of bone pain and improved quality of life. Although renal function in most patients gradually declined, none of the patients developed end-stage renal disease (ESRD) during an average follow-up time of 31 months, and no case of MGUS has yet transformed into MM.