title: Characteristics of gastric B-cell lymphoma of mucosa-associated lymphoid tissue type involving multiple organs.
abstract: BACKGROUND
  Mucosa-associated lymphoid tissue (MALT) lymphoma involving multiple organs is not well characterized.
  
  
  METHODS
  To obtain a better understanding of gastric MALT lymphoma with multiple organ involvement, we compared Helicobacter pylori infection status; response to eradication therapy; prevalence of genetic abnormality, including t(11;18)(q21;q21); and clonality of tumor cells between patients with gastric MALT lymphoma with and without multiple organ involvement.
  
  
  RESULTS
  Of 54 patients with only gastric involvement, 51 were positive for H. pylori (94.4%), whereas only 3 of 9 patients with multiple organ involvement had the infection (33.3%). Among those who received eradication therapy, the remission rate in patients with only gastric involvement was significantly higher than that in patients with multiple organ involvement (71.4% vs 33.3%; P < 0.05). The positive rate of API2-MALT1 fusion transcripts was significantly greater in patients with multiple lesions with either single or multiple organ involvement than in those with a single gastric lesion (71.4% vs 12.5%; P < 0.05), but 2 of 2 patients with multiple gastric lesions had the fusion transcripts. Of 5 patients with multiple organ involvement tested for clonality of the CDR3 region, distinct clones were detected in lymphoma lesions in different organs in 3 patients, whereas the identical clone was present in the different lesions in the remaining 2 patients.
  
  
  CONCLUSIONS
  Gastric MALT lymphoma with multiple organ involvement is often associated with API2-MALT1 fusion transcripts. Moreover, H. pylori infection is rare in patients with multiple organ involvement as compared to those with only gastric involvement. Patients with gastric MALT lymphoma with multiple organ involvement who are positive for H. pylori are resistant to eradication therapy.
authors.affiliation: Department of Gastroenterology and Endoscopic Medicine, Kyoto University Hospital, 54 Shogoin, Sakyo, 606-8507, Kyoto, Japan.
authors.forename: Masahiro
authors.initials: M
authors.lastname: Iwano
authors.forename: Kazuichi
authors.initials: K
authors.lastname: Okazaki
authors.forename: Kazushige
authors.initials: K
authors.lastname: Uchida
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Nakase
authors.forename: Masaya
authors.initials: M
authors.lastname: Ohana
authors.forename: Yumi
authors.initials: Y
authors.lastname: Matsushima
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Inagaki
authors.forename: Tsutomu
authors.initials: T
authors.lastname: Chiba
mesh_terms: D000368:Aged; D000900:Anti-Bacterial Agents / Q000627:therapeutic use; D000897:Anti-Ulcer Agents / Q000627:therapeutic use*; D001483:Base Sequence / Q000235:genetics; D002880:Chromosomes, Human, Pair 11; D002887:Chromosomes, Human, Pair 18; D004352:Drug Resistance, Microbial; D005260:Female; D005753:Gastric Mucosa / Q000473:pathology; D005770:Gastrointestinal Neoplasms / Q000188:drug therapy / Q000235:genetics / Q000473:pathology*; D016481:Helicobacter Infections / Q000188:drug therapy / Q000235:genetics / Q000473:pathology*; D016480:Helicobacter pylori / Q000187:drug effects; D006801:Humans; D007413:Intestinal Mucosa / Q000473:pathology; D018442:Lymphoma, B-Cell, Marginal Zone / Q000188:drug therapy / Q000235:genetics / Q000473:pathology*; D008297:Male; D008875:Middle Aged; D009378:Neoplasms, Multiple Primary / Q000188:drug therapy / Q000235:genetics / Q000473:pathology*; D015514:Oncogene Proteins, Fusion / Q000235:genetics*; D020133:Reverse Transcriptase Polymerase Chain Reaction; D013274:Stomach Neoplasms / Q000188:drug therapy / Q000235:genetics / Q000473:pathology*; D014178:Translocation, Genetic / Q000235:genetics
chemical_list: C415943:API2-MALT1 fusion protein, human; D000900:Anti-Bacterial Agents; D000897:Anti-Ulcer Agents; D015514:Oncogene Proteins, Fusion