What distinguishes Hodgkin lymphoma?

• A. Malignancy of melanocytes in skin.
• B. Heterogeneous group of lymphoid cancers with variable aggressiveness and unpredictable spread.
• C. Malignancy of plasma cells in bone marrow.
• D. Presence of Reed-Sternberg cells and predictable lymph node spread pattern.

Answer: (D)

Hodgkin lymphoma is distinguished by the presence of Reed-Sternberg cells in the affected lymphoid tissue and by a pattern of orderly, contiguous spread through lymph node regions. Reed-Sternberg cells are large, often binucleated B cells with prominent nucleoli that give an owl-eyed appearance under the microscope. This combination—the distinctive cells plus the predictable, stepwise nodal spread—sets Hodgkin lymphoma apart from other lymphoid cancers. By contrast, non-Hodgkin lymphomas are a heterogeneous group with variable aggressiveness and spread, plasma cell malignancies involve the bone marrow, and melanomas arise from skin melanocytes.