Comparison of bone marrow aspirate cytology, touch imprint cytology and trephine biopsy for bone marrow evaluation

Studies have compared the role of bone marrow aspirate cytology and trephine biopsy for diagnosing various hematological disorders but fewer studies have compared the relative value of imprint cytology with aspirate and trephine biopsy. The present study was conducted to compare the role of bone marrow aspirate, touch imprint and trephine biopsy to formulate an effective and rapid method for diagnosing wide spectrum of hematological diseases. The study included total 565 cases of bone marrow examination from January 2006 till May 2010. All the smears and sections were reviewed for morphological details and findings on aspirate, imprint and biopsy were compared to each other. The diagnostic accuracy of bone marrow aspirate was 77.5%, imprint cytology 83.7% and that of biopsy was of 99.2%. The study showed 78% positive correlation between aspirate and biopsy and 84.3% between imprint and biopsy; 93.3% cases of metastatic solid tumors were correctly diagnosed on imprint while only 70% cases were diagnosed on aspirate cytology. The study concludes that all the three preparations of aspirate, imprint and biopsy complement each other. The assessment of iron status by Perl's stain is most suitable on aspirate smears but trephine biopsy remains the gold standard for diagnosing granulomatous inflammation and hypoplastic/aplastic anemia. Meticulously prepared imprint smears not only provide cellular composition of marrow but may also be helpful in defining the architecture of marrow especially in cases of metastatic solid tumors. Imprint cytology smears should be standard practice for evaluating any marrow.