title: Extrasalivary lymphoma development in Sjögren's syndrome: clonal evolution from parotid gland lymphoproliferation and role of local triggering.
abstract: OBJECTIVE
  To characterize Sjögren's syndrome (SS)-related B cell lymphoproliferation at the premalignant stage and during the evolution to B cell lymphoma, and to better understand the pathobiologic mechanisms associated with clonal expansion and the possible influence of different microenvironments on neoplastic transformation.
  
  
  METHODS
  We analyzed sequential parotid and lung biopsy specimens that were obtained from a single patient with SS at multiple time points over a 7-year period. Polymerase chain reaction DNA amplification, cloning, and sequencing of the immunoglobulin heavy chain variable region showed clonality, somatic mutations, intraclonal heterogeneity, and genealogic relationships of the B cell clones in the different biopsy specimens.
  
  
  RESULTS
  The evolution of a nonmalignant B cell clone that was present in the parotid gland and evolved into a B cell lymphoma was documented. During such a process, one subclone was selected that accumulated somatic mutations in a pattern consistent with the preservation of antigen receptor functionality, possibly attributable to continued hypermutation and selection. Intraclonal diversity indicated the presence of local triggers in both the parotid and lung microenvironments.
  
  
  CONCLUSIONS
  Molecular followup of B cell lymphoproliferation in SS, from nonmalignant stage to overt B cell lymphoma, indicated a role for B cell receptor engagement in clonal survival. The outgrowth of one subclone, with malignant transformation in the lung, a target organ different from the initial site of the lymphoproliferative process (the parotid gland), indicates that resident stimuli in different microenvironments may locally sustain ongoing lymphoproliferation and B cell transformation.
authors: Centro di Riferimento Oncologico, Istituto di Ricovero e Cura a Carattere Scientifico, Aviano, Italy.
authors: Daniela
authors: D
authors: Gasparotto
authors: Salvatore
authors: S
authors: De Vita
authors: Valli
authors: V
authors: De Re
authors: Alessandra
authors: A
authors: Marzotto
authors: Ginevra
authors: G
authors: De Marchi
authors: Cathryn Ann
authors: CA
authors: Scott
authors: Annunziata
authors: A
authors: Gloghini
authors: Gianfranco
authors: G
authors: Ferraccioli
authors: Mauro
authors: M
authors: Boiocchi
mesh_terms: D000328:Adult; D002455:Cell Division; D002999:Clone Cells; D004252:DNA Mutational Analysis; D004273:DNA, Neoplasm / Q000032:analysis; D005260:Female; D006801:Humans; D007143:Immunoglobulin Heavy Chains / Q000235:genetics; D007135:Immunoglobulin Variable Region / Q000235:genetics; D016393:Lymphoma, B-Cell / Q000150:complications* / Q000235:genetics / Q000473:pathology; D010306:Parotid Gland / Q000473:pathology*; D016133:Polymerase Chain Reaction; D012333:RNA, Messenger / Q000032:analysis; D012334:RNA, Neoplasm / Q000032:analysis; D012859:Sjogren's Syndrome / Q000150:complications* / Q000235:genetics / Q000473:pathology
chemical_list: D004273:DNA, Neoplasm; D007143:Immunoglobulin Heavy Chains; D007135:Immunoglobulin Variable Region; D012333:RNA, Messenger; D012334:RNA, Neoplasm