Background and aims: In diagnostic immunohistochemistry (IHC), daily quality control/quality assurance measures (QC/QA) and participation in external quality assurance programmes (EQA) are important in ensuring good laboratory practice and patient care. Bone marrow trephine biopsies (BMTB) have been generally excluded from EQA programmes for diagnostic IHC due to a lack of standards for tissue processing. The European Bone Marrow Working Group (EBMWG) has set up an EBMWG IHC Committee with the task of exploring the plausibility of an EQA programme for BMTB IHC in Europe.
Methods: 28 laboratories participated in a web-based anonymous survey; 19 laboratories submitted a total of 109 slides stained for CD34, CD117, CD20, CD3, Ki-67 and a megakaryocyte marker of choice.
Results: Eight different fixatives and nine different decalcification methods were used. While 93% of participants believed that they produced excellent results in BMTB IHC, only 4/19 (21%) laboratories did not have any poor results. CD117 and Ki-67, with 53% and 50% poor results, respectively, were the most problematic immunostains, while CD20 was the least problematic, with only 11% poor results.
Conclusions: The EBMWG IHC Committee calls for a reduction in the tissue processing methods for BMTB and establishment of an EQA programme for BMTB IHC to help diagnostic IHC laboratories calibrate their tests according to expert recommendations. This is especially necessary in the light of recent introduction of predictive IHC tests in BMTB.