Is leukopenia the symptom of bone marrow cancers like leukemia?

Sometimes: Leukopenia (low white blood cell count) can be a symptom of bone marrow cancers like leukemia or myelodysplasia. There are many other less serious reasons to have low white blood cells too.

Many causes: Depending on which type of white cell is decreased, the cause may be leukemia (there may not be leukemic cells in the blood itself) or any of dozens of other causes. Low neutrophils commonly results from medication allergies, there are genes that cause them to drop episodically, and some people are allergic to quinine in beverages. Of these, leukemia is the easiest to rule in or out. Good luck.