The definitive diagnosis can be established with a bone marrow examination. A manual review is the recommended and gold standard method. Immunophenotyping using flow cytometry can also be used, although false blast counts are possible using this method. Loss of blast and non-blast cells during processing for the flow cytometry can sometimes lead to artifactually decreased or elevated counts.
Reexamination of the patient's peripheral blood smear (based on 200 cell count) and examination of a smear of the patient's bone marrow aspirate yielded the following results:
- Peripheral blood 6% blasts
- Bone marrow hypercellular with 10% blasts
Chromosomal analysis showed a deletion of the long arm of chromosome 7, known as del(7q).
