From the Guidelines
Hodgkin lymphoma is characterized by the presence of giant cells called Reed-Sternberg cells. These cells are a hallmark of the disease and are essential for diagnosis 1. They are large, multinucleated cells with a distinctive appearance, often described as having an "owl-eye" appearance due to prominent nucleoli. Reed-Sternberg cells originate from B lymphocytes that have undergone malignant transformation and are typically surrounded by a mix of inflammatory cells, including lymphocytes, histiocytes, eosinophils, and plasma cells. Some key characteristics of Reed-Sternberg cells include:
- Large size with multiple nuclei or a bilobed nucleus
- Prominent nucleoli, giving an "owl-eye" appearance
- Origin from B lymphocytes that have undergone malignant transformation
- Typically make up a small percentage of the total cell population in affected lymph nodes The identification of these cells through biopsy and histopathological examination is crucial for distinguishing Hodgkin lymphoma from other lymphoid malignancies and determining appropriate treatment strategies 1. The presence of Reed-Sternberg cells, along with the characteristic inflammatory background, forms the histological basis for diagnosing and classifying the different subtypes of Hodgkin lymphoma.
From the Research
Characteristics of Hodgkin Lymphoma
- Hodgkin lymphoma (HL) is characterized by the presence of giant multinucleated tumor cells called Hodgkin/Reed-Sternberg (H/RS) cells 2
- These cells are large, often multinucleated with a peculiar morphology and an unusual immunophenotype, that does not resemble any normal cell in the body 3
- H/RS cells are the clonal tumour cells of HL and derive from B cells in nearly all cases of HL, with rare cases deriving from T cells 3
Origin of Giant Cells in Hodgkin Lymphoma
- The development of Reed-Sternberg (RS) cells has remained obscure, but continuous live cell imaging has revealed that RS cells develop from mononucleated progenitors that divide and subsequently re-fuse, before they grow and become multinucleated giant cells 4
- This process is neither due to cell fusion of unrelated Hodgkin cells nor to endomitosis, as previously suggested 4
Pathogenesis and Immune Response
- The pathogenesis of HL is still largely unresolved, but aberrant activation of several signalling pathways, such as the NFkappaB pathway, is of key importance for H/RS cell survival 3
- The presence of an extensive inflammatory infiltrate is a characteristic of classical HL, comprising Th2 and T regulatory cells, and generally lacking Th1 cells, CD8 cytotoxic T cells, and natural killer (NK) cells 5