What distinguishes Non-Hodgkin lymphoma?

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

Answer: (A)

Non-Hodgkin lymphoma is defined by being a broad, heterogeneous group of lymphoid cancers that can arise from B cells, T cells, or NK cells. This diversity means the diseases vary greatly in how they behave, from indolent forms that progress slowly to very aggressive ones that spread quickly. Because of this variety, the spread is often unpredictable and can involve lymph nodes in many regions as well as extranodal sites, without a single, uniform pattern. In contrast, Hodgkin lymphoma is characterized by the presence of Reed-Sternberg cells and tends to follow a more predictable, contiguous spread from one lymph node region to another. The other options describe melanocyte malignancies (melanoma) and plasma cell malignancies (multiple myeloma), which are distinct from lymphoid cancers.