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.

Validation of a novel alcohol-free preservative solution in comparison with conventional prefixation on quality of serous body fluid smears.

BACKGROUND: We describe a novel alcohol-free preservative composed of glucose, mannitol, disodium hydrogen orthophosphate, thymol, and distilled water (glucose-mannitol-disodium dihydrogen orhtophosphate-thymol [GMDT] preservative) in appropriate proportion as an alternative to alcohol prefixation (APF) of body fluids. OBJECTIVES: To assess the cytomorphologic preservation and staining quality of serous body fluid smears generated by GMDT preservative and compare it with smears processed by standard 50% APF. METHODOLOGY: The study comprised 151 effusion samples. Each sample was equally divided into four tubes. Equal volumes of APF and GMDT preservatives were added to the first two tubes and left at room temperature for 24 h. Similarly, the corresponding preservatives were added to the third and fourth tubes and stored for 48 h. Two smears were prepared from the centrifuged sediments of each tube (all four tubes) and stained with May-Grünwald Giemsa and Papanicolaou (Pap) stains. Using a three-tiered scoring system, the smear examination was blinded to assess the extent of cellular preservation and the staining quality by two cytotechnologists and two cytopathologists. Statistical analysis was performed by STATA 16.0. RESULTS: Samples processed with the GMDT preservative at 24 h showed better cytoplasmic preservation and smear background, while nuclear features and staining quality showed no difference between the two preservatives. Mild cytoplasmic and nuclear degenerative changes were noted with the GMDT at 48 h, while all four parameters remained similar with APF at 24 and 48 h. CONCLUSIONS: The newly developed alcohol-free, GMDT preservative, could be a feasible and cost-effective alternative to 50% APF, preferably when samples are processed within 24 h.