When Haematopoiesis Goes Wrong Quiz

See Leukaemia. Option B is correct. Both leukaemia and lymphoma are cancers of blood-forming cells, and both come from precursor cells that have become abnormal, so what separates them is where the cancer cells live. In leukaemia the abnormal cells mainly sit in the bone marrow and spill into the blood. They crowd out normal blood cell production, so the patient develops anaemia (tiredness, pallor), frequent infections because the immature white cells cannot fight pathogens, and bleeding or bruising from too few platelets. In lymphoma the abnormal cells mainly sit in lymph nodes and other tissues, which is why a painless swollen node is the classic sign. Leukaemia is also classified in two ways: acute or chronic (how fast it progresses and how mature the cells are) and myeloid or lymphoid (which cell line it comes from). This gives four main types: acute myeloid, chronic myeloid, acute lymphoblastic and chronic lymphocytic leukaemia. The boundary can blur, since a lymphoid leukaemia can look like a lymphoma, but the main site of disease is the working rule.

• Leukaemia: abnormal cells mainly sit in the bone marrow and spill into the blood.
• Lymphoma: abnormal cells mainly sit in lymph nodes and other tissues.
• Classic sign: a painless swollen node points to lymphoma.