The document discusses five cases presenting with symptoms of different types of leukemia. The first case is a 10-year-old boy with fever and swollen lymph nodes. Diagnosis is acute lymphoblastic leukemia based on low blood cell counts and a bone marrow exam showing over 20% lymphoblasts. The second case is a 50-year-old woman with fever, weight loss, and enlarged organs. Diagnosis is acute myeloid leukemia based on low blood counts and classification is by the WHO system. Special stains on bone marrow can identify myeloperoxidase. The third case is a 40-year-old man with weakness and enlarged spleen. Diagnosis is chronic myeloid leukemia with a