Hematology_WBC_Leukemias

The WBC's seen here are lymphocytes, but they are blasts--very immature cells with larger nuclei that contain nucleoli. Such lymphocytes are indicative of acute lymphocytic leukemia (ALL). ALL is more common in children than adults. Many cases of ALL in children respond well to treatment, and many are curable.

These mature lymphocytes are increased markedly in number. They are indicative of chronic lymphocytic leukemia, a disease most often seen in older adults. This disease responds poorly to treatment, but it is indolent.

Here are very large, immature myeloblasts with many nucleoli. A distincitve feature of these blasts is a linear red "Auer rod" composed of crystallized granules. These findings are typical for acute myelogenous leukemia (AML) that is most prevalent in young adults.

There are numerous granulocytic forms seen here, including immature myeloid cells and bands. This condition is one of the myeloproliferative states and is known as chronic myelogenous leukemia (CML) that is most prevalent in middle-aged adults. A useful test to help distinguish this disease is the leukocyte alkaline phosphatase (LAP) score, which should be low with CML and high with a leukemoid reaction.

Here is another view of a peripheral blood smear in a patient with CML. Often, the numbers of basophils and eosinophils, as well as bands and more immature myeloid cells (metamyelocytes and myelocytes) are increased. Unlike AML, there are not many blasts with CML.