Immunohistochemistry on epoxy resin-embedded bone marrow biopsy experience with 936 cases

The investigators adapted a method to process 150 bone marrow trephine biopsies per year at a general hospital providing pathological diagnosis for a subcenter hematological ward. In brief, specimens were fixed in 10% formaldehyde and embedded in epoxy resin at 56°C without decalcification. The resin was extracted with sodium-etoxide from the sections. Following rehydration, immunohistochemistry was carried out similar to the paraffin method with the usual antigen retrieval and Envision-DAB development. High resolution cytomorphology and immunomorphology was possible without semithin technique. The turnaround time was 3 days: 1 day each for fixation, for resin infiltration/polymerization and for cutting/staining. The antibody panel included 40 to 50 primary antibodies. The final diagnoses were aided by smear morphology, flow cytometry, and lymphoid organ pathology, as required by the special circumstances of the cases.