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What is Which is the most common subtype of classical Hodgkin lymphoma? and explain in detail?
The WHO classification recognizes two major types of Hodgkin lymphoma: Classical Hodgkin lymphoma (CHL) & Nodular lymphocyte predominant Hodgkin lymphoma (NLPHL) Classical Hodgkin lymphoma is fuher classified into four subtypes: Nodular sclerosis - most common form of Hodgkin lymphoma, constituting 65% to 70% of cases. Mixed-cellularity - constitutes about 20% to 25% of cases. Lymphocyte-rich - uncommon Lymphocyte-depleted - least common, <5% cases, predominantly seen in HIV-positive patients. The Reed-Sternberg cells in Classical HL have a similar distinctive immunophenotype: Positive for CD15, CD30 and weakly positive for PAX5 (a B-cell transcription factor) Negative for other B-cell markers (CD20), CD45 (leukocyte common antigen) and T-cell markers In case of Nodular Lympocyte predominant Hodgkin lymphoma (NLPHL): RS cell variant 'Popcorn cells' are present, which are CD15 and CD30 negative and positive for CD20.