The Yokohama system for reporting Breast FNAB Cytopathology allows to systematize the results of  Breast Fine Needle Aspiration Biopsy (FNAB), increase their reproducibility and improve the quality of cytological diagnostics. In order to assess the diagnostic value of (FNAB) Electronic medical records of 503 female and 1 male patients with nodular formations in the mammary gland were studied as part of a triple test for the differential diagnosis of nodular formations of the breast. The results of clinical examination (palpation, external examination), X-ray and cytological studies were compared. The Yokohama system for reporting Breast FNAB Cytopathology was used to interpret cytological findings. The risk of malignancy in the C1 diagnostic category  was 3.6%,  C2 – 3,0%,  C3 – 16.7%,  C4 – 75%, C5 – 100%. The sensitivity and specificity of FNAB, mammography and clinical examination were 78.9% and 95.2%; 69% and 90.7%; 16.2% and 92.5%, respectively; accuracy – 87.5%; 78.2% and 83.8%, respectively. In total, the triple test showed sensitivity – 89.9%, specificity – 93.9%, accuracy – 92.4%. Breast FNAB showed the highest accuracy in the triple test. The C1 and C2 diagnostic categories do not exclude the presence of a malignant tumor, therefore, when interpreting cytological findings, it is necessary to take into account clinical and radiological data. The Yokohama system for reporting Breast FNAB the facilitates the clinician's interpretation of the results of cytological examination.

Irina Lisichnikova has 24 years of experience as a cytopathologist, of which 15 years in an oncological hospital. Currently, she heads the section of cytological diagnostics  of the clinical diagnostic laboratory The State Scientific Center of the Russian Federation of the A.I. Burnazyan Federal Medical and Biological Center of the Federal Medical and Biological Agency.