Leukopenia is not necessarily indicative of leukemia. There are many causes for a decrease in white blood cells, some of which can be due to medications. Currently, many drugs can cause a reduction in white blood cells, and in such cases, stopping the drug will typically allow the white blood cells to return to normal. A second scenario, especially in patients with an enlarged spleen or those suffering from cirrhosis, can also lead to a decrease in white blood cells. In these cases, it is mainly the abnormal function of the spleen that causes the reduction in white cells. Additionally, there are blood-related diseases, which might be leukemia or other types of blood disorders. In these situations, not only is there a reduction in white blood cells, but there is also a decrease in hemoglobin and platelets. Moreover, a significant increase in white blood cells is also a manifestation of leukemia, thus a decrease in white cells is not definitively indicative of leukemia.