IRTA1 and MNDA Expression in Marginal Zone Lymphoma

Utility in Differential Diagnosis and Implications for Classification

Wang, Zhen MD, PhD
Cook, James R MD, PhD

¹ Department of Laboratory Medicine, Robert J. Tomsich Pathology and Laboratory Medicine Institute, Cleveland Clinic, Cleveland, OH

Corresponding author: James R. Cook, MD, PhD;[email protected].

American Journal of Clinical Pathology 151(3):p 337-343, March 2019. | DOI: 10.1093/ajcp/aqy144

ABSTRACT

Objectives:

To evaluate the clinical utility of immune receptor translocation-associated protein 1 (IRTA1) and myeloid nuclear differentiation antigen (MNDA) expression in the diagnosis and classification of marginal zone lymphomas (MZLs).

Methods:

IRTA1 was examined using a novel RNA in situ hybridization assay and MNDA expression determined by immunohistochemistry in 127 small B-cell neoplasms, including 80 cases of MZL.

Results:

IRTA1 expression was detected in 31 (42%) of 74 MZLs vs one (2%) of 43 other small B-cell neoplasms (P < .001). MNDA staining was positive in 51 (64%) of 79 MZLs vs 21 (45%) of 46 non-MZLs (P = .06). MNDA expression was particularly uncommon in follicular lymphoma (3/14, 21%; P = .003 vs MZL). There was no association between MNDA and IRTA1 expression and the presence of monocytoid cytology. IRTA1 expression was less frequent in cases with a diffuse growth pattern.

Conclusions:

IRTA1 and MNDA are useful markers in the differential diagnosis of MZLs.