syndromes, and chronic myeloid leukaemia

Introduction The standard approach to the diagnosis of acute leukaemia and myelodysplasia has been based on the morphology and percentage of malignant haemopoietic cells in peripheral blood and in an aspirated sample of bone marrow. The FAB group reports on acute leukaemia have emphasised the value of additional information gained from cytochemistry,' and immunological studies and cytogenetics are increasingly being used to provide an accurate diagnosis in acute leukaemia2 and myelodysplasia. Aspirated bone marrow only provides a small sample which is diluted with sinusoidal blood and provides no information on the architectural changes occurring within the marrow cavity as a result of the leukaemic process. An adequate core biopsy sample permits a more accurate analysis of the degree of involvement of the marrow by the leukaemic process and may provide additional information on the response of normal marrow elements to the malignant infiltrate. Despite these advantages marrow core biopsy is not widely accepted as an essential requirement in the investigation of haemopoietic malignancies. One reason for this may be the view that decalcification and paraffin-wax embedding of such biopsy specimens produces distortion and shrinkage, resulting in difficulty in interpreting cellular morphology. This problem can be overcome by using plastic embedding of biopsy specimens,3 but satisfactory morphological details may also be obtained with improved methods of processing paraffin-wax embedded material,4" with the additional advantage that such processing also allows the use of immunocytochemical techniques. This review will assess the value of marrow core biopsy as a routine diagnostic procedure in the investigation of acute leukaemia, myelodysplasia, and chronic myeloid leukaemia.