Diagnostic accuracy of fine-needle aspiration cytology of the breast in Japan: report from the Working Group on the Accuracy of Breast Fine-Needle Aspiration Cytology of the Japanese Society of Clinical Cytology.

The Working Group of the Japanese Society of Clinical Cytology was assembled to assess the current status of breast cytology in Japan by conducting a large-scale survey regarding the accuracy of fine-needle aspiration biopsy (FNAB) in Japan. We collected data and investigated the status of breast cytological diagnosis at 12 different cooperating facilities in Japan, and re-evaluated their false-negative and false-positive cases. Among 30,535 individuals who underwent a breast cytological examination, analyses were conducted on 10,890 individuals (35.