Lymphomatoid papulosis with DUSP22–IRF4 rearrangement: A case report and literature review

Abstract

Lymphomatoid papulosis (LyP) with DUSP22–IRF4 rearrangement is a rare, recently described variant of LyP histopathologically characterized by a biphasic growth pattern, with epidermotropic small‐to‐medium‐sized atypical T‐cells and dermal large and transformed T‐cells diffusely expressing CD30. LyP with DUSP22–IRF4 rearrangement can mimic other cutaneous lymphoproliferative disorders, particularly primary cutaneous anaplastic large cell lymphoma (PCALCL) or transformed mycosis fungoides (MF). Unlike PCALCL or transformed MF, LyP with DUSP22–IRF4 rearrangement shows an indolent clinical behavior, with frequent spontaneous regression of untreated lesions. Thus, it is important to recognize this rare variant of LyP to avoid misclassification, which may potentially lead to unnecessarily aggressive patient management. To our knowledge, only 13 cases of LyP with DUSP22–IRF4 rearrangement have been reported to date in the English literature. Herein, we describe an additional case of LyP with DUSP22–IRF4 rearrangement in a 63‐year‐old man and provide a comprehensive literature review with regards to the clinical, histopathologic, and molecular features of this novel entity.

Histopathological Markers for Target Therapies in Primary Cutaneous Lymphomas

“…Recurrent t (6;7) (p25.3;q32.3) translocations, involving the DUSP22-IRF4 locus on 6p25.3, have been identified in ALK-negative ALCL, including cutaneous cases. This translocation is expressed in a specific LyP variant but is rarely present in MF with LCT, serving as a potential diagnostic criterion [32,47].…”