title: Unusual discordant responses in two multiple myeloma patients during bortezomib treatment.
abstract: BACKGROUND
  Cases of discordant responses in multiple myeloma (MM) patients after thalidomide therapy have been sometimes reported, in which extramedullary masses progress or present de novo with a simultaneous serum monoclonal protein reduction.
  
  
  METHODS
  We hereby report, for the first time, on two cases of MM patients with extramedullary myeloma localizations that developed during Velcade (bortezomib, PS341) treatment with a concomitant serum monoclonal protein reduction.
  
  
  RESULTS
  We observed in both patients a very good response in the serum monoclonal protein level, while extramedullary lesions appeared in the central nervous system and subcutaneously.
  
  
  CONCLUSIONS
  We discuss pharmacokinetics of bortezomib and physiopathology of this unusual event and review the literature.
authors.affiliation: Division of Hematology and Transplants, University of Siena, Policlinico Santa aria alle Scotte, Siena, Italy.
authors.forename: Maria Teresa
authors.initials: MT
authors.lastname: Pirrotta
authors.forename: Alessandro
authors.initials: A
authors.lastname: Gozzetti
authors.forename: Alfonso
authors.initials: A
authors.lastname: Cerase
authors.forename: Alessandro
authors.initials: A
authors.lastname: Bucalossi
authors.forename: Monica
authors.initials: M
authors.lastname: Bocchia
authors.forename: Marzia
authors.initials: M
authors.lastname: Defina
authors.forename: Francesco
authors.initials: F
authors.lastname: Lauria
mesh_terms: D000368:Aged; D000970:Antineoplastic Agents / Q000627:therapeutic use*; D001897:Boronic Acids / Q000627:therapeutic use*; D000069286:Bortezomib; D002531:Cerebellum / Q000473:pathology; D003907:Dexamethasone / Q000627:therapeutic use; D018450:Disease Progression; D004305:Dose-Response Relationship, Drug; D004334:Drug Administration Schedule; D019008:Drug Resistance, Neoplasm; D017809:Fatal Outcome; D005260:Female; D006801:Humans; D007145:Immunoglobulin kappa-Chains / Q000097:blood; D007146:Immunoglobulin lambda-Chains / Q000096:biosynthesis; D008297:Male; D008578:Meninges / Q000473:pathology; D009101:Multiple Myeloma / Q000188:drug therapy* / Q000473:pathology; D009361:Neoplasm Invasiveness; D009367:Neoplasm Staging; D010950:Plasma Cells / Q000473:pathology; D011719:Pyrazines / Q000627:therapeutic use*; D012867:Skin / Q000473:pathology
chemical_list: D000970:Antineoplastic Agents; D001897:Boronic Acids; D007145:Immunoglobulin kappa-Chains; D007146:Immunoglobulin lambda-Chains; D011719:Pyrazines; D000069286:Bortezomib; D003907:Dexamethasone