Atypical marginal zone hyperplasia of mucosa-associated lymphoid tissue: a reactive condition of childhood showing immunoglobulin lambda light-chain restriction

Blood. 2004 Nov 15;104(10):3343-8. doi: 10.1182/blood-2004-01-0385. Epub 2004 Jul 15.

Abstract

Mucosa-associated lymphoid tissue (MALT) lymphomas usually arise at sites of acquired MALT and are uncommon in native MALT (eg, Peyer patches and tonsil). Malignancy in these low-grade lymphomas is often inferred by immunoglobulin light-chain restriction and expression of CD43; molecular genetic evidence is sought only if these are in doubt. We report 6 cases (4 tonsils, 2 appendixes) of marginal zone (MZ) hyperplasia in children aged 3 to 11 years that, despite histologic and immunophenotypic features indicative of lymphoma, were polyclonal by molecular analysis. No lymphoma-directed therapy was given and patients remain alive and well (5 cases, median follow-up 35.3 months). The involved tonsil and appendix showed florid MZ hyperplasia with prominent intraepithelial B cells (IEBCs). The MZ B cells and IEBCs showed a high-proliferation fraction and a CD20(+), CD21(+), CD27(-), immunoglobulin (Ig) superfamily receptor translocation-associated 1-positive (IRTA-1(+)), CD43(+), multiple myeloma oncogene 1 (MUM-1), IgM(+)D(+) phenotype. Polymerase chain reaction (PCR), cloning, and sequencing of rearranged IgH and Iglambda genes (whole tissue sections [6 cases]; microdissected cells [2 cases]) showed that the MZ B cells and IEBCs were polyclonal and the IgH genes nonmutated. In contrast, MZ (intraepithelial) B cells of 6 control tonsils had a similar immunophenotype, except for expression of CD27 and polytypic light chains, whereas molecular studies showed that they were polyclonal with mutated Ig genes.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Appendix / pathology*
  • B-Lymphocytes / physiology
  • Cell Division / immunology
  • Child
  • Child, Preschool
  • Diagnosis, Differential
  • Female
  • Follow-Up Studies
  • Gene Expression
  • Humans
  • Hyperplasia
  • Immunoglobulin lambda-Chains / genetics*
  • Immunophenotyping
  • Lymphoma, B-Cell, Marginal Zone / immunology*
  • Lymphoma, B-Cell, Marginal Zone / pathology*
  • Lymphoma, B-Cell, Marginal Zone / physiopathology
  • Male
  • Palatine Tonsil / pathology*

Substances

  • Immunoglobulin lambda-Chains