Low-grade follicular lymphoma with interferon regulatory factor-4 rearrangement: Expanding the spectrum of interferon regulatory factor-4-rearranged lymphomas.

In recent years, the recognition of distinct lymphoma entities has expanded with advancements in molecular characterization. Large B-cell Lymphoma with interferon regulatory factor-4 () rearrangement (LBCL--R) is one such entity. We present a case of classic low-grade follicular lymphoma with rearrangement in a 50-year-old male, demonstrating an unusual immunophenotypic and genetic profile reminiscent of LBCL--R. Molecular analysis revealed mutations in , , , and , with previously unreported variants identified in and . This case broadens the spectrum of B-cell lymphomas associated with rearrangement by demonstrating a small B-cell lymphoma with this genetic feature.