Self‐clotting method improves cell block preparation

BACKGROUND The success of cell block preparation is crucial for ancillary diagnostic tests in cytology. However, achieving an optimal cell block can be challenging. The current study describes a self‐clotting‐based technique for fine‐needle aspiration (FNA) cell block preparations and evaluates its usefulness in comparison with the conventional needle wash technique. METHODS The clinical data, FNA procedure, and cellularity of cell blocks of the self‐clotting group (37 cases) and the conventional needle wash group (33 cases) were compared. The cellularity was evaluated using a scoring system (0 indicated acellular, 1 indicated 1‐50 cells, and 2 indicated >50 cells). RESULTS Approximately 76% of cases in the self‐clotting group received a score of 2 versus 36% in the conventional needle wash group. Approximately 14% received a score of 1 in the self‐clotting group compared with 9% in the conventional needle wash group, whereas 11% in the self‐clotting group received a score of 0 versus 55% in the conventional needle wash group. The differences between the 2 methods were statistically significant. CONCLUSIONS The results of the current study demonstrate that the self‐clotting method is superior to the conventional needle wash method for FNA samples. Cancer Cytopathol 2018;126:190‐9. © 2017 American Cancer Society. The authors created a modified cell block preparation technique allowing fine‐needle aspiration samples to self‐clot in a dry tube before the addition of any liquid media. This method appears to be superior to the conventional needle rinse method because it avoids diluting fine‐needle aspiration samples in liquid media and maximizes the collection of cellular material by holding the aspirate tightly in a blood clot.