History of Leukemia, Revisited.

Purpose of the review: Provide a general historical overview of leukemia, emphasizing the early discoveries that led to its characterization.

Recent findings: Leukemia recognition began in the late 19th century with the advent of the microscope. Leeuwenhoek and Swammerdam described erythrocytes, while Lieutaud first observed globuli albicantes, later identified as lymphocytes by Hewson. Early case studies by Velpeau, Donné, Bennett, Craigie, Virchow, and Fuller suggested that leukocytosis could occur without infection. Virchow coined the term "leukemia," while Bennett proposed "leucocythemia." Neumann identified the bone marrow as the source of blood cells and leukemia, coining the term "myelogenous leukemia," and Ehrlich classified leukemia into myeloid and lymphoid types. In 1914, Boveri linked chromosomal abnormalities to cancer, and in 1960, Nowell and Hungerford discovered the Philadelphia chromosome. The use of mustard gas in WWI led to the development of chemotherapy drugs like chlorambucil and busulfan. The Human Genome Project further advanced leukemia diagnosis and treatment. Leukemia, like many diseases, has evolved due to changes in causative factors such as viruses, bacteria, and genetic mutations, which have impacted its pathogenesis and treatment. It will undoubtedly continue to evolve, with new scientists working towards a cure for this devastating disease.