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Breast Cytology - Undetermined Diagnoses and Unsatisfactory Samples

an increase in accuracy and in better acceptance and trust of breast fine-needle aspiration (FNA) cytology by radiologists and by patients. Weigner et al. [1] report 4% C3/atypical categorizations with a 37.4% PPV. These results lie within the range published in the literature. We would just like to offer some comments based also on our recent experience with liquid-based cytology (LBC) samples [7] . We hope that they could eventually help our Australian colleagues to further improve their accuracy. In the earlier literature, equivocal diagnoses (atypical and suspicious categorizations) most often depended on technical factors such as limited cellularity, obscuring factors and/or drying artifacts, while 2% of samples showed really ambiguous cellular patterns [8] . It is possible that modern intensive screening is increasing the number of the latter type of samples, related to true borderline lesions situated in the ‘gray zone’. However, technical factors still seem to have an important impact in the series of Weigner et al. [1] . Their C1/unsatisfactory rate was 12.6%. In addition, 34.8% of their cases with C3/atypical categorizations being suboptimal or even unsatisfactory at rescreen. These data suggest that improving the quality of the samples in the preanalytical phase could be useful. A careful selection of the patients can further reduce the number of unsatisfactory samples. Dear Editor, We have read with interest the paper on the true nature of atypical breast cytology published by Weigner et al. [1] in Acta Cytologica . The authors report on their experience with samples from a governmentfunded screen program and a private breast clinic located on the east coast of Australia. Breast cytology is a very efficient diagnostic method especially in integrated teams, where there is close on-site collaboration between radiologists and pathologists [2] . However, breast cytology has been criticized because of the elevated number of C1/unsatisfactory samples and of uncertain (C3/atypical and C4/suspicious) categorizations [3] that generate anxiety and expose patients to the risk of overtreatment. We agree with Weigner et al. [1] that the C3/atypical categorization is useful to reduce the risk of false-negative diagnoses. In spite of its benefit, this categorization is particularly bothersome because of its low positive predictive value (PPV) explained by the borderline nature of the underlying lesions. Many of the C3/atypical diagnoses correspond to benign proliferative or lowgrade malignant (mostly in situ) lesions [4, 5] . Uncertainty is increased because these cases are often associated with ambiguous radiological findings [1] that show significant interobserver variability [6] . Thus, reducing the C3/atypical report rate in favor of conclusive categorizations will result in Received: December 9, 2013 Accepted after revision: January 3, 2014 Published online: February 18, 2014