How Accurately FNAC Reflects the Breast Papillary Lesions?

Diagnosis of papillary lesions of the breast by fine needle aspiration cytology (FNAC) is problematic. For this reason, it is situated in the indeterminate zone in classification systems.

To ascertain the accuracy of cytological diagnosis of papillary lesions in distinguishing papillary lesions from non-papillary lesions and to determine whether papillomas can be reliably distinguished from malignant papillary lesions by FNAC.

A total of 346 cases with the diagnoses of breast papillary lesions were selected among 5112 breast FNAC procedures performed in our center. One hundred and thirty-nine cases with excised lesions were included in this study, and their corresponding histology was reviewed.

Papillary lesion diagnosis was confirmed by histopathology in 103 (74.1%) of 139 patients. Cytology and histopathology results were not found to be compatible in 35 (25.2%) cases. The diagnostic accuracy of distinguishing papillary breast lesions as malignant or benign was assessed statistically. According to the cytology-histology comparison, one case was evaluated as false negative (FN) and twelve cases as false positive (FP). Overall accuracy, sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) of FNAC in distinguishing papillary lesions as benign or malignant were calculated as 87%, 97%, 83%, 72%, and 98%, respectively.

The diagnostic accuracy of papillary breast lesions classified by FNAC might be improved by careful evaluation together with cytological, radiological, and clinical findings (triple test). Cell block may allow more accurate evaluation of the papillary lesion and can be applied to immunohistochemical examination. It may also facilitate the differentiation of benign/malignant papillary lesions.