What is used to distinguish between Acute Myeloid Leukemia (AML) and Acute Lymphoblastic Leukemia (ALL)?

Immunophenotyping is a critical tool used to distinguish between Acute Myeloid Leukemia (AML) and Acute Lymphoblastic Leukemia (ALL). This technique involves analyzing the types of surface markers (antigens) present on the cells in a blood or bone marrow sample. AML and ALL have distinct immunophenotypic profiles, with specific clusters of differentiation (CD) markers that characterize the lineage of the malignant cells. For instance, AML cells typically express myeloid markers such as CD13, CD33, and CD117, while ALL cells usually express lymphoid markers such as CD10, CD19, or CD34.

While a blood smear can provide initial information about the presence of abnormal cells, it is not definitive in differentiating between AML and ALL due to overlap in the morphological characteristics of the leukemic cells. A bone density scan is not relevant for diagnosing these types of leukemia, as it primarily assesses bone density and health rather than blood cell abnormalities. Similarly, urinalysis is used to detect metabolic and systemic conditions and does not provide information about hematological malignancies. Therefore, immunophenotyping is the most reliable method for accurately distinguishing between these two forms of leukemia.