RESUMEN
BACKGROUND: In general, chronic myelogenous leukemia (CML) are classified according to the criteria established by the International Bone Marrow Transplant Registry. However, when a marrow aspirate cannot be obtained because of myelofibrosis or other causes, bone marrow biopsy specimens can be used to provide diagnostic information. As compared with the marrow aspirate, the assessment of the blasts is a major difficulty with biopsy specimen. Anti-CD34 is a monoclonal antibody that reacts with leukemic blasts and bone marrow progenitor cells, immunohistochemical staining for CD34 can be used to classify three phases of CML when the aspirates of bone marrow is inadequate. METHODS: The authors studied 38 bone marrow biopsy specimens, it were diagnosed as CML, representing three phases of disease (chronic, accelerated, and blastic crisis). Immunohistochemical staining for CD34 was performed using CD34 monoclonal antibody in paraffin- embedded tissue. We assess a correlation between the clinical phases of CML and the proportion of CD34 positive cells. RESULTS: The proportion of CD34 positive cells among chronic, accelerated, blastic phases, and indeterminate group of CML were 4.3 (1.7~9.0)%, 10.1 (7.4~12.7)%, 31.2 (10.2~87.3)%, and 13.35 (8.7~20.0)%, respectively. The differences in CD34 positivity between various phases of CML were highly significant (P=0.0001). We classified CML according to bone marrow histology; granulocytic types and granulocytic/megakaryocytic (mixed) type. The differences in CD34 positivity among histologic types were significant high proportion of CD34 positive cells (P=0.0191) in granulocytic type of blastic phase. CONCLUSION: This study demonstrated that CD34 immunohistochemical staining represents a reliable method for classifying CML in cases in where a bone marrow aspirate is not available, and further studies are needed in order to find out the relationship between a degree of CD34 positivity and histologic classification.