Patients with chronic granulocytic leukemia have variations in blood platelets as seen in routine blood tests, which differ according to different stages of the disease. In the chronic phase, especially early on, platelet counts are mostly elevated or normal, with increases potentially exceeding 1000x10^9 per liter. The shape of the platelets is normal, but their function is often abnormal, with thrombus formation being rare. A minority of patients may experience a decrease in platelet count. As the disease progresses, routine blood tests can reveal significant decreases or increases in platelet counts along with the appearance of megakaryocytes. Additionally, some patients may also exhibit bone marrow fibrosis, characterized by an increase in reticular fibers or collagen fibers.