Diagnosing leukemia can be a straightforward matter that requires little more than analysis of a complete blood count. Too many white blood cells or too few red blood cells could herald leukemia. Flow cytometry may reveal the specific types of blood cell running amok—or not. Sometimes, leukemia stays in the bone marrow, making identification of the specific type more difficult. In those cases, a patient faces a more complex process that typically requires a bone marrow biopsy.