title: Clinicopathological features of gastric mucosa-associated lymphoid tissue lymphoma: a comparison with diffuse large B-cell lymphoma without a mucosa-associated lymphoid tissue lymphoma component.
abstract: OBJECTIVE
  The aim of this study was to clinicopathologically distinguish the pathogenesis of gastric mucosa-associated lymphoid tissue (MALT) lymphoma and diffuse large B-cell lymphoma without a MALT lymphoma component (DLL).
  
  
  METHODS
  We investigated clinicopathological features of these gastric lymphomas including age, sex ratio, tumor location and depth, macroscopic appearance, and infection with Helicobacter pylori of these gastric lymphomas and hepatitis viruses in 24 patients with gastric low-grade MALT lymphoma, 10 patients with high-grade MALT lymphoma, and 19 patients with DLL. The frequency of H. pylori infection in lymphoma patients was compared with that in age- and sex-matched control subjects.
  
  
  RESULTS
  There was a predominance of females with MALT lymphoma (male to female ratio, 8/16 for low-grade MALT lymphomas and 1/9 for high-grade MALT lymphomas), and there was a predominance of males with DLL (male to female ratio, 13/6); the ratios differed significantly (P < 0.05). Ninety-two percent of low-grade MALT lymphomas and 80% of high-grade MALT lymphomas were confined to the mucosal and submucosal layers, but lymphoma cells invaded the muscular layer or more deeply in 74% of DLL. Helicobacter pylori infection occurred significantly more often in patients with low-grade MALT lymphoma than in age- and sex-matched controls (96 vs 67%, P < 0.01). Conversely, the frequency of H. pylori infection in DLL patients did not differ from that in controls.
  
  
  CONCLUSIONS
  These data suggest that H. pylori infection may be associated with the development of gastric MALT lymphoma, but not DLL, and that MALT lymphoma and DLL may have a different pathogenesis.
authors.affiliation: First Department of Internal Medicine, Hiroshima University School of Medicine, Hiroshima, Japan.
authors.forename: T
authors.initials: T
authors.lastname: Hiyama
authors.forename: K
authors.initials: K
authors.lastname: Haruma
authors.forename: Y
authors.initials: Y
authors.lastname: Kitadai
authors.forename: H
authors.initials: H
authors.lastname: Masuda
authors.forename: M
authors.initials: M
authors.lastname: Miyamoto
authors.forename: M
authors.initials: M
authors.lastname: Ito
authors.forename: T
authors.initials: T
authors.lastname: Kamada
authors.forename: S
authors.initials: S
authors.lastname: Tanaka
authors.forename: N
authors.initials: N
authors.lastname: Uemura
authors.forename: M
authors.initials: M
authors.lastname: Yoshihara
authors.forename: K
authors.initials: K
authors.lastname: Sumii
authors.forename: F
authors.initials: F
authors.lastname: Shimamoto
authors.forename: K
authors.initials: K
authors.lastname: Chayama
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D005260:Female; D016481:Helicobacter Infections / Q000150:complications; D016480:Helicobacter pylori; D006509:Hepatitis B / Q000150:complications; D006526:Hepatitis C / Q000150:complications; D006801:Humans; D016393:Lymphoma, B-Cell / Q000473:pathology*; D018442:Lymphoma, B-Cell, Marginal Zone / Q000473:pathology*; D016403:Lymphoma, Large B-Cell, Diffuse / Q000473:pathology*; D008297:Male; D008875:Middle Aged; D009361:Neoplasm Invasiveness; D012737:Sex Factors; D013274:Stomach Neoplasms / Q000473:pathology*