Hodgkin Lymphoma: Biology and Differential Diagnostic Problem

Hodgkin lymphomas (HLs) are lymphoid neoplasms that are morphologically defined as being composed of dysplastic cells, namely, Hodgkin and Reed-Sternberg cells, in a reactive inflammatory background. The biological nature of HLs has long been unclear; however, our understanding of HL-related genetics and tumor microenvironment interactions is rapidly expanding. For example, cell surface overexpression of programmed cell death 1 ligand 1 (CD274/PD-L1) is now considered a defining feature of an HL subset, and targeting such immune checkpoint molecules is a promising therapeutic option. Still, HLs comprise multiple disease subtypes, and some HL features may overlap with its morphological mimics, posing challenging diagnostic and therapeutic problems. In this review, we summarize the recent advances in understanding the biology of HLs, and discuss approaches to differentiating HL and its mimics.

Automated summary

Hodgkin lymphomas are lymphoid neoplasms characterized by dysplastic cells and interactions with the tumor microenvironment. Overexpression of CD274/PD-L1 is considered a defining feature of an HL subset, and targeting immune checkpoint molecules shows promise as a therapeutic option. However, the presence of multiple disease subtypes and overlap with morphological mimics poses challenging diagnostic and therapeutic problems in HLs.