title: Marginal zone mucosa associated lymphoid tissue diffuse large B cell lymphoma.
abstract: BACKGROUND
  Non-Hodgkin's lymphomas (NHL) primarily involving the orbit, is relatively uncommon. Rarely two pathologically different NHL cell types have been found to be coexistent.
  
  
  METHODS
  We report a case of orbital lymphoma in a 62-year-old male with rare histopathological findings secondary to transformation of once cell type into another. Tissue diagnosis and molecular studies led to revelation of diffuse large B cell lymphoma evolving from MALT lymphoma.
  
  
  CONCLUSIONS
  Proliferation of two morphologically and phenotypically different B cells resulting in malignancy has not been found in the orbit so far. They are usually aggressive tumors and require chemo-immunotherapy.
authors.affiliation: Department of Internal Medicine, University of Alabama at Birmingham Health Center Montgomery, Alabama, United States.
authors.forename: Adrian Pedro Noriega
authors.initials: AP
authors.lastname: Aldave
authors.affiliation: Department of Internal Medicine, University of Alabama at Birmingham Health Center Montgomery, Alabama, United States.
authors.forename: Shikha
authors.initials: S
authors.lastname: Jaiswal
authors.affiliation: Department of Internal Medicine, University of Alabama at Birmingham Health Center Montgomery, Alabama, United States.
authors.forename: Stephen L
authors.initials: SL
authors.lastname: Davidson
keywords: Diffuse large B cell lymphoma; Marginal zone mucosa-associated lymphoid tissue lymphoma; Orbital lymphoma; Rituximab