Reed-Sternberg cells (RSC) are the diagnostic hallmark of classic Hodgkin lymphoma.
Reed-Sternberg cells (also called Hodgkin and Reed-Sternberg or HRS cells) are the characteristic large, abnormal neoplastic cells found in classical Hodgkin lymphoma (cHL).
Large, abnormal cells derived from B lymphocytes (usually germinal center B cells).
Classically binucleated or multinucleated, giving an “owl’s eye” appearance under the microscope.
Each nucleus has a prominent, large nucleolus.
Abundant cytoplasm
Findings of these cells in a lymph node biopsy is what confirms a Hodgkin lymphoma diagnosis, as opposed to non-Hodgkin lymphoma.
They make up only a small fraction (often ~1%) of the cells in involved tissue; the bulk consists of a reactive inflammatory infiltrate of lymphocytes, eosinophils, neutrophils, histiocytes, and plasma cells.
RSCs typically scattered sparsely within a background of normal inflammatory cells of lymphocytes, eosinophils, plasma cells, macrophages— the RS cells themselves are usually the minority.
They express characteristic surface markers: CD30 and CD15 positive, but usually CD45 negative, unlike most lymphocytes, and CD20 (or only weakly/focally positive).
They are typically derived from germinal-center or post-germinal-center B lymphocytes that have undergone V(D)J recombination and somatic hypermutation.
Despite this B-cell origin, they usually lose expression of most B-cell-specific genes and markers, including functional immunoglobulin.
Classic Reed-Sternberg cells are large (commonly 15–50 μm or larger) with abundant cytoplasm.
Their presence (in the appropriate inflammatory background) is required for the diagnosis of classical Hodgkin lymphoma and helps distinguish it from non-Hodgkin lymphomas.
Similar-appearing cells can occasionally occur in other conditions (e.g., infectious mononucleosis, certain non-Hodgkin lymphomas, or drug reactions), so context and immunophenotyping are essential.
Epstein–Barr virus is present in the cells in a substantial proportion of cases (roughly 30–50% overall, varying by subtype and geography).
Reed-Sternberg cells are the defining malignant cells of classical Hodgkin lymphoma, notable for their distinctive “owl-eye” morphology, unusual immunophenotype, B-cell origin with loss of B-cell identity, and ability to orchestrate a prominent reactive microenvironment despite being rare within the tumor.