COVID-19 and breast fine needle aspiration cytology method: What should we change?

Introduction: Air-dried slide preparation for fine needle aspiration cytology procedures is currently considered unsafe because of the risk of infectious aerosols of coronavirus 19. This study compares the safety and accuracy of two different protocols, one with and one without air-dried slides.

Methods: Starting from 3 March 2020, we discontinued the use of air-dried slides during breast fine needle aspiration procedures. We selected cases collected during two periods: 2 months before and 2 months after 3 March. In both groups, the number of procedures was recorded together with the distribution of the diagnostic categories and the concordance between cytological and histological results on surgical specimens for lesions suggestive of malignancy, using the chi-squared test.

Results: Of the 100 procedures performed during the pre-COVID-19 period, 55% were negative (C2), 3% were non-diagnostic (C1) and 40% were positive (C4 or C5). Of the 75 procedures obtained during the COVID-19 period, 44% were negative (C2), 2.7% were non-diagnostic (C1) and 52% were positive (C4 or C5). Despite the use of a new protocol during the COVID-19 period, we observed concordance between cytological and histological results for lesions suggestive of malignancy. There was no statistically significant difference concerning the distribution of the diagnostic categories in the two groups.

Conclusions: Taking into account the slightly lower number of procedures being analysed during the COVID-19 period, the introduction of a new protocol that does not include air-dried slides is safe and reliable.