Primary cutaneous CD4+ small/medium pleomorphic T‐cell lymphoproliferative disorder: Where do we stand? A systematic review

Abstract

Primary cutaneous CD4+ small/medium pleomorphic T-cell lymphoproliferative disorder (PCSMP-TLPD) is a provisional entity with uncertain malignant potential according to the latest revision of the WHO classification for lymphoid neoplasms. We conducted a systematic literature review of all previously reported cases of PCSMP-TLPD to highlight their typical and atypical features. The main features of PCSMP-TLPD and its possible clinicopathologic overlap with similar disorders are also discussed. It is hoped that this review will provide a useful outline of this condition and the most important differential diagnoses. Finally, we recommend a rigorous consensus among cutaneous lymphoma experts in drafting diagnostic criteria and the best case definition.

Successful treatment with imatinib of lymphomatoid papulosis associated with myeloproliferative hypereosinophilic syndrome with PDGFRA rearrangement

“…No evident epidermotropism was observed. These findings were diagnosed as consistent with LyP type A [9,10] and ruled out other differential diagnoses [10][11][12]. Laboratory tests showed peripheral eosinophilia (4,140/mm 3 ).…”

The histone methyltransferase DOT1L prevents antigen-independent differentiation and safeguards epigenetic identity of CD8+T cells

“…The fact that a substantial fraction of the remaining CD4 + T cells had not lost DOT1L activity indicates that the CD4 + compartment and especially regulatory T cells depend on DOT1L for their normal development. Further research exploring the dependency of CD4 + T cells on DOT1L may provide novel strategies for immune modulation and treatment of CD4 + T cell malignancies 76,77 .…”

Brownish asymptomatic lesions on the arms and legs

“…In some cases of drug-induced PPD, histology can show atypical lymphocytes. Due to the possible presence of a lichenoid infiltrate consisting of small lymphocytes with atypical cytology, differential diagnosis between MF and CD4+ lymphoproliferative disorder can be difficult [7,9,10]. In such circumstances, clinical involvement confined to the legs, presence of a CD8+ infiltrate shown with immunohistochemistry, as well as polyclonal TCR rearrangement can be helpful.…”