Haema 2012; 3(3): 190-202
by Sotirios G. Papageorgiou, Vasiliki Pappa, Ioannis Dervenoulas
Second Department of Internal Medicine, Propaedeutic, Hematology Unit, University of Athens, University General Hospital “Attikon”
Hodgkin lymphoma (HL) is a neoplasm of lymphoid tissue, derived from mature B cells of germinal center and subdivided into classical and nodular lymphocyte predominant HL (NLPHL). HL is unique among human B cell neoplasms due to the rarity of the malignant cells, the Hodgkin and Reed- Sternberg (HRS) cells in classical HL and the lymphocyte-predominant (LP) cells in NLPHL, which usu- ally account for less than 1% of the cells in the affected tissues. Moreover, HRS cells are unique in the extent to which they show an abnormal reprogramming of B lymphocytic differentiation. This causes an abnormal and complex immunophenotype that is characterized by the expression of a wide range of antigens that are normally expressed by several distinct cell types. Deregulation of cell signaling pathways and transcription factors plays a key role in HL pathogenesis. Finally, HRS cells are found within a mixed reactive non-malignant cellular environment and interact with these nonmalignant cells in a complex fashion that appears to be essential for HRS cell survival and proliferation.