Leukemic cells growth fraction in the central nervous system in blastic phase of chronic myelogenous leukemia.

Clinical and neuropathological investigations were carried out in 6 patients, deceased due to blastic phase of chronic myelogenous leukemia (BPCML). Growth fraction of leukemic cells in peripheral blood, cerebrospinal fluid and in the central nervous system (CNS) was studied, using mitotic index and immunohistochemical staining technique with the monoclonal antibody antiproliferating cell nuclear antigen (anti-PCNA). The results suggest that in BPCML the proliferative activity of leukemic cells is low both in peripheral blood, cerebrospinal fluid, cerebral leukostasis and within the leptomeningeal and intracerebral infiltrates, even in cases with a very high white blood cells count. It can confirm the opinion that in BPCML, accumulation rather than proliferation of leukemic cells plays an important role in the development of the CNS leukemia.