Comparison of the quality of the microwave cell-block method with the conventional cell-block method in processing body fluid samples.

Introduction: Conventional cell blocks (CCB) prepared from cytological specimens are very useful but the method is relatively time-consuming. Suitable modifications in cell-block techniques are beneficial for improving the turnaround time. We share our experience of a rapid microwave cell-block (MCB) technique.

Aim And Objectives: To study the quality of routine and immunohistochemical (IHC) staining of cell-block sections from serous body fluids prepared by the MCB technique compared with the CCB technique.

Method: A total of 177 serous body fluid samples were processed by routine centrifugation technique, and the sediments were used for cell-block preparations by both conventional and rapid microwave methods. Cell-block sections were stained with haematoxylin and eosin stain. Haematoxylin and eosin staining quality was analysed using three parameters (cellularity, morphology and staining intensity). IHC for epithelial membrane antigen and calretinin were also performed, and the quality of staining was evaluated on 62/177 samples. Results were analysed using appropriate statistical tests.

Results: The time taken for processing cell blocks by the MCB method was 1 hour and 18 minutes compared to 13 hours and 45 minutes by CCB. The quality of sections by both methods showed good agreement for cellularity and intensity of staining, and moderate agreement for morphology. A 100% concordance was noted for distinguishing benign and malignant samples on morphology as well as with IHC stain results.

Conclusion: Although the techniques are comparable in terms of quality of routine and IHC staining, we recommend using the MCB technique due to its short turnaround time.