Professional and Linguistic Assessments Board (PLAB) Practice Exam

Which condition would most likely show increased granulocyte counts on a blood smear?

1. Chronic Myeloid Leukemia (CML)

2. Acute Lymphoblastic Leukemia

3. Multiple Myeloma

4. Polycythemia Vera

The correct answer is: Chronic Myeloid Leukemia (CML)

Increased granulocyte counts on a blood smear are most notably associated with Chronic Myeloid Leukemia (CML). CML is a type of cancer that affects the myeloid line of blood cells, leading to an overproduction of these cells, including granulocytes. This increase is often marked by the presence of immature granulocyte forms, such as myeloblasts, in the peripheral blood. The pathophysiology of CML involves a genetic mutation that typically results in the Philadelphia chromosome, which plays a crucial role in the overproduction of myeloid lineage cells, including basophils, eosinophils, and neutrophils. Over time, as the disease progresses, patients may also exhibit a high white blood cell count, with granulocytes being the predominant type. In contrast, conditions like Acute Lymphoblastic Leukemia, Multiple Myeloma, and Polycythemia Vera do not primarily feature an increase in granulocyte counts on blood smears. Acute Lymphoblastic Leukemia primarily affects lymphocytes. Multiple Myeloma is characterized by an increase in plasma cells and typically does not lead to granulocyte proliferation. Polycythemia Vera involves increased red blood cell mass, but while it may affect white