title: Marginal zone B-cell lymphoma: A clinical comparison of nodal and mucosa-associated lymphoid tissue types. Non-Hodgkin's Lymphoma Classification Project.
abstract: OBJECTIVE
  In the International Lymphoma Study Group classification of lymphoma, extranodal marginal zone B-cell lymphoma (MZL) of mucosa-associated lymphoid tissue (MALT) type is listed as a distinctive entity. However, nodal MZL is listed as a provisional entity because of questions as to whether it is truly a disease or just an advanced stage of MALT-type MZL. To resolve the issue of whether primary nodal MZL without involvement of mucosal sites exists and whether it is clinically different from extranodal MALT-type lymphoma, we compared the clinical features of these two lymphomas.
  
  
  METHODS
  Five expert hematopathologists reached a consensus diagnosis of MZL in 93 patients. Seventy-three were classified as having MALT-type MZL because of involvement of a mucosal site at the time of diagnosis, and 20 were classified as having nodal MZL because of involvement of lymph nodes without involvement of a mucosal site.
  
  
  RESULTS
  A comparison of the clinical features of nodal MZL and MALT-type MZL showed that more patients with nodal MZL presented with advanced-stage disease (71% v 34%; P =. 02), peripheral lymphadenopathy (100% v 8%; P <.001), and para-aortic lymphadenopathy (56% v 14%; P <.001) than those with MALT-type MZL. However, fewer patients with nodal MZL had a large mass (> or = 5 cm) than those with MALT-type MZL (31% v 68%; P =.03). The 5-year overall survival of patients with nodal MZL was lower than that for patients with MALT-type MZL (56% v 81%; P =.09), with a similar result for failure-free survival (28% v 65%; P =.01). Comparisons of patients with International Prognostic Index scores of 0 to 3 showed that those with nodal MZL had lower 5-year overall survival (52% v 88%; P =.025) and failure-free survival (30% v 75%; P =.007) rates than those with MALT-type MZL.
  
  
  CONCLUSIONS
  Nodal MZL seems to be a distinctive disease entity rather than an advanced stage of MALT-type MZL because the clinical presentations and survival outcomes are different in these two types of MZL. Clinically, nodal MZL is similar to other low-grade, node-based B-cell lymphomas, such as follicular and small lymphocytic lymphomas.
authors.affiliation: University of Southern California (USC) and Los Angeles County+USC Healthcare Network, Los Angeles, CA 90033, USA.
authors.forename: B N
authors.initials: BN
authors.lastname: Nathwani
authors.forename: J R
authors.initials: JR
authors.lastname: Anderson
authors.forename: J O
authors.initials: JO
authors.lastname: Armitage
authors.forename: F
authors.initials: F
authors.lastname: Cavalli
authors.forename: J
authors.initials: J
authors.lastname: Diebold
authors.forename: M R
authors.initials: MR
authors.lastname: Drachenberg
authors.forename: N L
authors.initials: NL
authors.lastname: Harris
authors.forename: K A
authors.initials: KA
authors.lastname: MacLennan
authors.forename: H K
authors.initials: HK
authors.lastname: Müller-Hermelink
authors.forename: F A
authors.initials: FA
authors.lastname: Ullrich
authors.forename: D D
authors.initials: DD
authors.lastname: Weisenburger
mesh_terms: D000328:Adult; D003937:Diagnosis, Differential; D005260:Female; D006801:Humans; D016393:Lymphoma, B-Cell / Q000145:classification / Q000175:diagnosis / Q000473:pathology*; D018442:Lymphoma, B-Cell, Marginal Zone / Q000175:diagnosis / Q000401:mortality / Q000473:pathology*; D008224:Lymphoma, Follicular / Q000175:diagnosis / Q000401:mortality / Q000473:pathology*; D008297:Male; D008875:Middle Aged