PAS staining, also known as glycogen staining, is positive for the diagnosis of disease and is commonly used for the diagnosis of diabetes, lung disease, cardiomyopathy, and other cardiovascular diseases. In particular, a positive PAS stain is significant for malignancies, such as acute and chronic lymphocytic leukemia, malignant lymphoma and lung cancer, as well as megaloblastic anemia and hemolytic anemia. It is clinically useful as an adjunctive test and can be performed under the guidance of a physician. Like leukemia cells with massive involvement and proliferation resulting in suppression of normal hematopoietic function and in both bone marrow and other hematopoietic tissues, aggressive treatment is required and PAS staining is repeatedly applied to determine their therapeutic status.