Adequacy of trephine bone marrow biopsies: the doctor and the patient make a difference

Reports of 1938 trephines submitted from five institutions over a 30-month period were analyzed looking for associations between the hospital of origin, operator, bone marrow pathology, patient's age and the biopsy quality. The arbitrary adequacy criteria (min 10 mm of interpretable marrow or min 10 intertrabecular spaces) were fulfilled by 61.9% of the biopsies. The performance of individual operators varied from 15.9% to 87.8% of adequate trephines. The group of doctors performing more than 100 biopsies in the study period had satisfactory results. The intermediate group (20-100 biopsies) was the least homogenous, and on the average had the poorest biopsy quality. The biopsy quality was influenced by diagnostic categories, correlated positively with bone marrow fibrosis and negatively with the patient's age. The trephine quality in practice may be lower than the published or declared standards. Ideally the procedure should be executed by the practitioners making more than one trephine a week. Prior to the biopsy it is possible to estimate the level of difficulty posed by an individual patient and use this information to minimize the risk of obtaining an inadequate core.