Patch/plaque mycosis‐fungoides‐like presentations of DUSP22‐translocated T‐cell lymphomas

The DUSP22‐IRF4 gene rearrangement results in downregulation of DUSP22, a presumed tumor suppressor in T‐cell lymphomagenesis. It has been described in some cases of primary cutaneous and systemic anaplastic large‐cell lymphoma, lymphomatoid papulosis, and transformed mycosis fungoides. Here we describe two patients with clinical lesions resembling patch/plaque mycosis fungoides that did not meet WHO criteria for large‐cell transformation on histopathology yet showed a DUSP22 translocation. One patient who had a history of systemic anaplastic large‐cell lymphoma with DUSP22 translocation presented with cutaneous involvement by his systemic lymphoma along with lymphomatoid papulosis and mycosis‐fungoides‐like lesions, all showing an identical immunophenotype and T‐cell clone. These cases expand the spectrum of DUSP22‐rearranged lymphomas to include mycosis‐fungoides‐like presentations without large‐cell transformation.