Loriza Khan^1
1Royal College of Pathologists of Australasia Quality Assurance Programs (RCPAQAP), St Leonards, Sydney

The examination of a bone marrow aspirate and biopsy is a critical component in the diagnosis and management of blood and bone marrow disorders. Combined with peripheral blood, the aspirated liquid marrow (aspirate) and core biopsy of bone (trephine) containing marrow tissue is used to evaluate the cell count, morphology and cellularity. Methods for extraction, preparation and interpretation may be prone to variances and inconsistencies. To avoid the impact of these differences in the diagnosis of haematological diseases, a number of guidelines are available to assist pathologists. Ubiquitously known guidelines in Australasia are the ICSH guidelines for the standardization of bone marrow specimens and reports (2008) and the RCPA Bone Marrow (Aspirate and Trephine) Structured Reporting Protocol (2014).

Despite the availability of these guidelines for several years, inconsistencies in reporting of the granulopoiesis quantitation and myeloid to erythroid (M:E) ratio from the cell differential count were noted in an external quality assessment program. In the case of an adult with acute leukaemia, WCC of 189.5 x10⁹/L, and 90% blasts, the participants reported M:E ratios ranging from 0 to 99, with a median of 30. This EQA case highlighted the differences in the appropriate quantitation of cells and subsequent reporting of the M:E ratio.