IRTA1 positivity helps identify a MALT-lymphoma-like subset of primary cutaneous marginal zone lymphomas, largely but not exclusively defined by IgM expression.

Journal Article (Journal Article)

BACKGROUND: It has been proposed that primary cutaneous marginal zone lymphomas (PCMZLs) include a MALT-lymphoma-like IgM+ subset and a class-switched subset, which is unlike most other MALT lymphomas. Whether expression of the MALT lymphoma-associated biomarkers IRTA1 and MNDA would support this concept and whether they might help explain why some patients have both subtypes is uncertain. METHODS: Twenty-five PCMZLs from 21 patients were stained for IRTA1 by in situ hybridization and for MNDA by immunohistochemistry. In two patients, polymerase chain reaction (PCR)-based B-cell clonality studies were performed on biopsy specimens of metachronous lesions, which expressed different heavy chains. All results were correlated with the histopathologic and clinical findings. RESULTS: Five of six IgM+ PCMZLs were IRTA1+ vs three of 18 evaluable class-switched cases (P = 0.0069). Two of the class-switched IRTA1+ cases were in patients with clonally-related IRTA1+ IgM+ PCMZLs. IRTA1 positivity showed a statistically significant correlation with several MALT-lymphoma-associated histopathologic findings. In contrast, all PCMZL cases showed at least some MNDA expression with no differences between IgM+ and class-switched cases. CONCLUSIONS: IRTA1 identifies MALT-lymphoma-like PCMZLs that are largely but not exclusively IgM+. This supports the concept of two PCMZL subsets but suggests their distinction should not be based solely on their heavy chain expression.

Full Text

Duke Authors

Cited Authors

  • Carlsen, ED; Bhavsar, S; Cook, JR; Swerdlow, SH

Published Date

  • January 2022

Published In

Volume / Issue

  • 49 / 1

Start / End Page

  • 55 - 60

PubMed ID

  • 34309899

Electronic International Standard Serial Number (EISSN)

  • 1600-0560

Digital Object Identifier (DOI)

  • 10.1111/cup.14111


  • eng

Conference Location

  • United States