Application of IAC Yokohama system for breast cytology – The experience at a tertiary care hospital

Abstract

Breast malignancies are one of the commonest malignancies in Indian women. Increasing urbanization is attributed to raise of breast cancers and have surpassed cervix cancer in recent times and are now ranked top in some metros. FNA is used as an important diagnostic tool as a part of triple assessment. The application of the IAC Yokohama system in breast cytology improves the reporting and also allows the calculation of risk of malignancy (ROM). The main aim of the study is to; 1. Apply the IAC Yokohama system for the diagnostic; 2. assessment and subsequent categorization of FNA samples and correlate them with histopathology examination (HPE); 3. calculate ROM; 4. Calculate p-value.A total of 305 samples received were diagnosed and classified according to the IAC Yokohama system. The study was conducted over a period of 2 yrs retrospectively from June 2019 to May 2021. For the 305 FNA samples received, HPE correlation was made and statistical parameters, ROM , p-value were calculated.305 FNA samples were obtained and categorized according to the IAC Yokohama system. They were categorized and the percentage of incidence noted as 1. Insufficient - 6.89%, 2.Benign - 72.46%, 3.Atypical probably benign - 3.28%, 4. Suspicious - 3.28%, 5. Malignant - 14.09%. ROM was also calculated. The distribution of cases in percentage as per categories are: category 1 – 0%, category 2 - 2%, category 3 – 0%, category 4- , 42.86% category 5- 100%. For 305 FNA samples reported 95 cases received for HPE and subsequently cyto – histopathological correlation was made and statistical parameters were calculated. Compiled statistics showed sensitivity of 100%, specificity of 93.54%, NPV of 100%, PPV of 89.19% and diagnostic accuracy at 95.78%. The p-value for the present study is 0.0001 which is very significant.Application of the IAC Yokohama system of reporting breast cytopathology helps in better categorization of FNA samples and it improves the efficacy of cytopathologist. It gives better clarity to the clinicians in the management of the patient and can reduce unnecessary surgeries.