Leukaemia is cancer of which tissues?

• A. Cancer of epithelial lining organs
• B. Cancer of blood-forming tissues in bone marrow causing abnormal white blood cell proliferation
• C. Cancer of adipose tissue
• D. Cancer of bone metastases

Answer: (B)

Leukaemia is a cancer of the blood-forming tissues, primarily the bone marrow, where blood cells are produced. In this disease, hematopoietic stem cells become malignant and continually produce abnormal white blood cells that proliferate and crowd out normal cells, leading to symptoms like infections and anemia. This is different from cancers of epithelial lining organs (carcinomas), cancers of fat tissue (lipomas or liposarcomas), or cancers that metastasize to bone from other sites. The defining tissue is the bone marrow’s hematopoietic tissue, which explains the hallmark overproduction of abnormal white blood cells.