Quality control of bone marrow cytology; organization and over 7 years experience in the south-west Netherlands

To asses the quality of bone marrow cytology of hospital laboratories in the south-west Netherlands a proficiency testing program was implemented. Two sets of bone marrow and blood smears from two patients were sent to 20 hospital laboratories using a tight time schedule biannually. Required results consisted of differential counts of 500 bone marrow cells and 100 peripheral blood cells, together with the description of morphological abnormalities and final conclusions. Twice a year the collected review data were discussed in a plenary session which was also used for continuous education. Over the past 7 years 30 bone marrow samples were evaluated. The coefficient of variations of specific cells counts was large. The amount of correct conclusions ranged from 12% to 100% (median: 61%). Participant attendance of the meetings was 90-100%. The total cost of this scheme of proficiency testing approximately amounted euro7000 per year. The presented formulae for both proficiency testing and haematopathological/cytological education is feasible and fulfilled the need of the participants.