Which type of leukemia does not exhibit peroxidase activity?

Acute lymphocytic leukemia (ALL) is characterized by the proliferation of lymphoid cells and does not exhibit peroxidase activity. This is largely due to the nature of the precursor cells involved in ALL, which are lymphoblasts. Lymphoid cells, unlike myeloid cells, lack the enzyme myeloperoxidase, which is responsible for the positive peroxidase activity typically seen in myeloid leukemias.

In contrast, acute myelogenous leukemia (AML) and chronic myelogeneous leukemia (CML) arise from myeloid lineage cells that express myeloperoxidase, leading to detectable peroxidase activity. Chronic lymphocytic leukemia (CLL) involves mature B cells that similarly do not show myeloperoxidase activity, but it is the acute form associated with lymphocytic lineage that is specifically highlighted for its lack of peroxidase activity. Hence, the identification of ALL as the type of leukemia without peroxidase activity is supported by these fundamental principles of hematology and cell lineage differentiation.