B cell lymphoma with IRF4 rearrangement: A clinicopathological study of 13 cases

Abstract

Interferon regulatory factor 4 (IRF4) rearrangement is commonly detected in patients with a range of lymphoproliferative malignancies, including myelomas, large B cell lymphomas and low‐grade B cell neoplasms. However, IRF4 rearrangement is generally a relatively rare finding in these latter two cancer types. In the present article, we describe and summarize the clinicopathological and genetic features of 13 cases of B cell lymphoma with IRF4 rearrangement, including 12 cases of large B cell lymphoma and one case of low‐grade lymphoma exhibiting such rearrangement. These cases were detected in six females and seven males between 14 and 71 years of age. From a morphological perspective, large B cell lymphoma tumors included in this analysis exhibited large neoplastic cells in diffuse or follicular patterns, while the case of low‐grade lymphoma mainly composed of small lymphocytes. All analyzed cases exhibited a split in the IRF4 gene consistent with IRF4 translocation. Three of six analyzed large B cell lymphoma cases harbored IGLL5 mutations. Mutations in SAMHD1 were detected in the low‐grade lymphoma with IRF4 rearrangement case. In summary, our results offer further insight into the morphological and molecular heterogeneity of cases of B cell lymphoma exhibiting IRF4 rearrangements.

SAMHD1 in cancer: curse or cure?

“…By now, a single case of an extremely rare low-grade B-cell lymphoma with IRF4 rearrangement with concomitant mutation in SAMHD1 (c.G692A; leading to premature a stop codon, W231X) was described [ 25 ]. Probably, this early stop-gain mutation in SAMHD1 will lead to reduced protein expression, which was not assessed in the report by Zhou et al In this patient, further missense and frameshift mutations were detected in the genes KMT2D , BTG1 , PTEN , and BAX [ 25 ].…”

Large B‐cell lymphoma with IRF4 rearrangement—Fine needle biopsy—Report of a case with an atypical presentation

“…The presence of macrophages with tingible bodies as well as dispersed apoptotic debris in the background, albeit reported in some papers is classically not described in this entity. 1,9,10 No immunoblastic-like cells, Sternberg Reed cells, pleomorphic cells or cells expressing CD30 were identified in our case. We also did not identify the presence of dendritic cells or histiocytes.…”

Pediatric-Type Follicular Lymphoma: A Short Review

“…Large B-cell lymphoma with IRF4 rearrangement lacks the starry sky appearance seen in PTFL. Moreover, an immunohistochemistry study showed BCL2 positivity in more than half of the cases with strong IRF4 / MUM1 expression [ 14 , 23 , 24 , 31 ].…”