A 35-year-old woman presents with mediastinal mass, fever, night sweats, and cervical lymphadenopathy. Biopsy shows large cells with bilobed nuclei, prominent owl-eye nucleoli, and a mixed inflammatory background. Immunohistochemistry shows CD15+, CD30+, CD45−, PAX5 dim+. The Reed-Sternberg cell in this disorder is thought to be derived from which cell lineage?
- A Post-germinal centre B cell that has lost normal B-cell gene expression ✓
- B Activated cytotoxic T lymphocyte
- C Follicular dendritic cell
- D Transformed natural killer cell
Correct answer: A. Post-germinal centre B cell that has lost normal B-cell gene expression
Explanation
Reed-Sternberg cells in classical Hodgkin lymphoma originate from germinal-centre or post-germinal-centre B cells that have paradoxically lost most B-cell surface markers (CD20, CD45 often negative) while retaining dim PAX5 expression. They are CD15+ and CD30+ and have undergone crippling somatic hypermutation that would normally trigger apoptosis but are rescued by NF-κB activation.
Reference: Robbins & Cotran Pathologic Basis of Disease, 10th ed.
High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP
Written and medically reviewed by the StethoPrep medical team.