title: Cast nephropathy: an extremely rare renal presentation of Waldenström's macroglobulinaemia.
abstract: Renal involvement in Waldenström's macroglobulinaemia (WM) is very unusual when compared to multiple myeloma. We report a case of a patient who developed anuric acute kidney injury secondary to cast nephropathy, dependent on high-flux haemodialysis. Complementary study revealed the presence of blood IgM monoclonal gammopathy and a massive bone marrow lymphoplasmacytic infiltration. There were no osteolytic lesions and no clinical signs/symptoms of hyperviscosity syndrome. The diagnosis of WM was established and a dexamethasone plus cyclophosphamide regime was started, in addition to plasmapheresis. The patient partially recovered renal function allowing haemodialysis and plasmapheresis withdrawal. He remained asymptomatic with a good response to chemotherapy and 12 months after his renal function remained stable. This is a rare clinical case in which WM presented as an IgM cast nephropathy, which in turn is an extremely rare renal presentation of this equally rare haematological disorder.
authors.affiliation: Department of Nephrology, Coimbra's Hospital and University Center, Coimbra, Portugal.
authors.forename: Tânia
authors.initials: T
authors.lastname: Santos
authors.affiliation: Department of Nephrology, Coimbra's Hospital and University Center, Coimbra, Portugal.
authors.forename: Susana
authors.initials: S
authors.lastname: Machado
authors.affiliation: Department of Pathology, Coimbra's Hospital and University Center, Coimbra, Portugal Coimbra's Medical College, Coimbra, Portugal.
authors.forename: Vítor
authors.initials: V
authors.lastname: Sousa
authors.affiliation: Department of Nephrology, Coimbra's Hospital and University Center, Coimbra, Portugal.
authors.forename: Mário
authors.initials: M
authors.lastname: Campos
mesh_terms: D000369:Aged, 80 and over; D001002:Anuria / Q000175:diagnosis / Q000378:metabolism; D006801:Humans; D007674:Kidney Diseases / Q000175:diagnosis* / Q000378:metabolism / Q000473:pathology; D008297:Male; D035583:Rare Diseases; D008258:Waldenstrom Macroglobulinemia / Q000175:diagnosis* / Q000378:metabolism / Q000473:pathology