Floatation of decalcified bone marrow core biopsy - a clue to marrow hypocellularity

Background : Examination of bone marrow plays a pivotal role in the practice of haematology. It can be evaluated by three ways - bone marrow aspiration smears (BMA), bone marrow touch imprints (BMI) and bone marrow biopsy (BMB). BMB sections are considered to be the gold standard for assessing overall marrow cellularity.

To evaluate the correlation, if any, between bone marrow cellularity and floatation pattern of the core biopsy specimen, after proper decalcification.

This study was carried out in the Department of Pathology, Institute of Medical Sciences, Varanasi over a period of 26 months.

Specimens of BMA, BMI and BMB were collected from 182 cases. The core biopsy specimens were fixed in 10% buffered formalin for 24 hours, and were decalcified in 5% formic acid for 12 hours. The properly decalcified core biopsy samples were then put into adequate-sized container filled with 10% buffered formalin, and floatation pattern was documented.

All the observations were evaluated using simple and basic statistical tools, i.e. sensitivity, specificity, positive predictive value. Chi square test was applied for obtaining statistical correlation i.e. p-value.

Out of 182 core biopsy specimens, 32.4% (n=59) floated, while rests sank. Out of the 59 floating core biopsies, 57 were hypocellular. Seven core biopsies, among 123 specimens that sank, were hypocellular. The sensitivity and specificity of floatation pattern for hypocellular marrow were 89.2% and 99.1%, respectively. A strong correlation (p-value <0.001) between the floatation pattern and bone marrow cellularity was obtained.

Assessment of floatation pattern of properly decalcified marrow core specimen is reliable for assessing marrow hypocellularity.