Pathomorphological diagnosis of primary cutaneous CD4-positive small/medium T-cell lymphoproliferative disorder: a 28-case series

Abstract

Introduction. Primary cutaneous CD4+ lymphoproliferative disorder of small and medium cells (PC CD4+ T-LPD small/medium cell) is a new entity identified in the WHO classification published in 2017. The aim of the research was to characterize morphological and immunohistochemical features of PC CD4+ T-LPD small/medium cell. Materials and methods. The study examined 28 skin biopsies from 13 males and 15 females with PC CD4+ T-LPD small/medium cell using histological and immunohistochemical methods. Results. We detected growth pattern to be of nodular, focal–diffuse, and diffuse types. Each case was characterized by significant T-cell lymphoid infiltration with an immunophenotype of follicular T-helper cells (Tfh-immunophenotype), the number of B-cells varying. Conclusion. PC CD4+ T-LPD from small and medium cells is a rare disease that requires further study to determine the criteria for diagnosis and treatment. Keywords: primary cutaneous CD4+ small/medium T-cell lymphoproliferative disorder, T follicular helper cells, immunophenotype