How we process trephine biopsy specimens: epoxy resin embedded bone marrow biopsies

Abstract

Improved cytomorphology of semithin resin sections over paraffin wax embedded sections may be important in diagnostic haematopathology. However, resin embedding can make immunohistochemical antigen detection or DNA isolation for clonal gene rearrangement assays difficult. This review describes the processing of bone marrow biopsies using buffered formaldehyde based fixation and epoxy resin embedding, with or without EDTA decalcification. Traditional semithin resin sections are completely rehydrated after etching in home made sodium methoxide solution. Resin elimination allows high resolution staining of tissue components with common histological stains. Efficient antigen retrieval and the Envision-HRP system permit the immunohistological detection of many antigens of diagnostic relevance, with retention of high quality cytomorphology. Furthermore, DNA can be extracted for clonality analysis. The technique can be completed within a similar time period to that of paraffin wax processing with only ∼30% increase in cost. This technique has been used for diagnosis in over 4000 bone marrow biopsies over the past 14 years. By meeting traditional and contemporary demands on the haematopathologist, it offers a powerful alternative to paraffin wax processing for diagnosis and research.

Diagnosis of unknown nonhematological tumors by bone marrow biopsy: a retrospective analysis of 10,112 samples

“…Compared with this report, our study detected a more than 3-fold higher (1%) metastasis rate. It is well known that routine paraYn-embedded sections were prevalent in preparation and availability by immunochemistry stain, but was morphologically little recessive when compared to plastic-embedded samples except those recently modiWed (Krenacs et al 2005;Naresh et al 2006). Consequently, we attribute the higher sensitivity of this assay to the advantages of plastic embedding of the BM core biopsy specimens, which reveals intricate cellular details due to the thinness of the sections and lacks the tissue distortion that is inevitable following decalciWcation procedures (Vincic et al 1989;Casey and Beckstead 1990).…”

Optimal processing of bone marrow trephine biopsy: the Hammersmith Protocol

“…2 6 Several papers deal with these issues and confirm adequate antigen and DNA preservation in resinembedded BMT specimens. [7][8][9][10] However, RNA preservation and suitability for ISH analyses of mRNA is not clear. The main criticism of this procedure is the requirement of specialised technology and skill and the additional costs associated with it.…”

ICSH guidelines for the standardization of bone marrow immunohistochemistry

“…Also, in short protocols, it is critical that all reagents are fresh (e.g., commercially available rapid decalcifying reagents will not perform optimally if diluted by large number of samples or if re‐used; supplier recommendations regarding recommended volumes and the possibility of re‐use should be followed closely). If the core biopsy is not properly decalcified, so‐called ‘surface decalcification’ or ‘decalcification on block’ is likely to be performed by histotechnologist during cutting of the block, the results of which cannot be fully predicted or controlled, but can be deleterious to some epitopes . Decalcification with simultaneous fixation is not recommended.…”