title: Paraneoplastic minimal change nephropathy: a diagnostic challenge.
abstract: BACKGROUND
  Myeloma-associated glomerulopathy could mimic idiopathic minimal change nephropathy, which poses a diagnostic challenge to nephrologists.
  
  
  METHODS
  A 60-year-old patient presented with nephrotic range of proteinuria. Serum creatinine level was normal. Immune markers and tumor markers were unrevealing. No monoclonal protein was detected on serum protein electrophoresis. Renal biopsy showed marked effacement of foot processes and no evidence of immunoglobulin or amyloid deposition on electron microscopy/immunofluorescence staining, compatible with idiopathic minimal change nephropathy histologically. However, proteinuria persisted despite steroid treatment. In view of the atypical course of the disease, workup for secondary glomerulopathy was repeated and paraproteinuria was unexpectedly found. Subsequent bone marrow examination confirmed light chain myeloma.
  
  
  CONCLUSIONS
  Urine protein electrophoresis and serum/urine immunofixation are useful tests to detect the monoclonal protein in suspicious cases.
authors.affiliation: Division of Nephrology, Department of Medicine, Queen Mary Hospital, Hong Kong - Hong Kong.
authors.forename: Maggie K M
authors.initials: MK
authors.lastname: Ma
authors.forename: Gavin S W
authors.initials: GS
authors.lastname: Chan
authors.forename: Kwok Wah
authors.initials: KW
authors.lastname: Chan
authors.forename: Man Fai
authors.initials: MF
authors.lastname: Lam
mesh_terms: D003404:Creatinine / Q000097:blood; D006801:Humans; D007147:Immunoglobulin Light Chains; D007668:Kidney / Q000473:pathology; D008297:Male; D008875:Middle Aged; D009101:Multiple Myeloma / Q000150:complications / Q000175:diagnosis*; D009402:Nephrosis, Lipoid / Q000175:diagnosis* / Q000209:etiology; D010257:Paraneoplastic Syndromes / Q000175:diagnosis*; D011507:Proteinuria / Q000175:diagnosis / Q000209:etiology
chemical_list: D007147:Immunoglobulin Light Chains; D003404:Creatinine