Mechanically Disaggregated Unfixed Trephine Biopsies Can be Used for Diagnostic Immunophenotyping in Acute Leukaemia

An adequate bone marrow sample is essential for a rapid diagnosis of acute leukaemia by multicolour flow cytometry enabling the assignment of lineage and choice of therapy.

Diagnosis is sometimes delayed due to difficulties in of obtaining a bone marrow aspirate due to a 'dry tap'.

In this study we evaluated immunophenotyping of mechanically disaggregated unfixed bone marrow trephine biopsies from 62 paediatric and adult patients at diagnosis (mostly acute leukemia). We compared the results to immunophenotyping of blood and aspirate samples and the trephine biopsy histology.

In 26 of 62 cases no disease was present in the blood and the aspirate was a 'dry tap'. In 24 of 26 cases a diagnosis was reached by immunophenotyping from the disaggregated bone marrow biopsy. Results were concordant with histopathology in all 24 cases (22 acute lymphoblastic leukemia(ALL) cases, 2 acute myeloid leukemia (AML) cases). In 2 cases insufficient cells were obtained from the disaggregated biopsy to reach a diagnosis.

In 36 of 62 cases immunophenotyping was performed on disaggregated unfixed bone marrow trephine biopsies and compared to immunophenotyping on blood and/or aspirate as well as histology. The immunophenotyping findings were concordant in 33 cases between the (21 ALL, 6 AML, 3 myelodysplastic syndromes|(MDS), 3 other haematological malignancies). In 3 cases insufficient cells could be obtained from the disaggregated biopsy. In one of these the histology from the bone marrow biopsy showed cortical bone only, while the other two showed AML and MDS.

In conclusion these data confirm earlier reports that immunophenotyping of mechanically disaggregated unfixed trephines is a useful diagnostic adjunct particularly where a dry tap has occurred.