Which marker is included in the common panel for Hodgkin's lymphoma?

• A. CD15
• B. CD3
• C. CD30
• D. CD45

Answer: (C)

CD30 is included because classic Hodgkin lymphoma is defined by Reed-Sternberg cells that characteristically express CD30. This marker is the most reliable for identifying the malignant RS cells within the inflammatory background, making it a staple in the diagnostic immunophenotyping panel. CD15 can also be positive in many RS cells, but it is not as consistently expressed as CD30. CD3 marks T cells in the surrounding reactive background, not the RS cells themselves, and CD45 (leukocyte common antigen) is typically negative on RS cells, helping distinguish them from other leukemias or lymphomas. So CD30 stands out as the key marker used in the common panel for Hodgkin lymphoma.