Breast cancer is one of the most common malignancies among females that has left behind the lung cancer by representing 11.7% of all cancer cases globally 1. A number of pre operative diagnostic modalities are used to diagnose breast cancer adequately and preferably on time. Out of which Fine Needle Aspiration Cytology (FNAC) is most commonly used rapid, sensitive, cost effective and less traumatic diagnostic method of breast lesions 2, 3. International Academy of Cytology (IAC) Yokohama system for reporting breast cytopathology, further aids to the diagnosing capacity of FNAC by classifying the breast lesions in different categories provided with a probable management option along with acceptable precalculated Risk Of Malignancy (ROM) 4, 5, 6. IAC Yokohama system provide better communication between the surgeon and the pathologist, hence improves the reproducibility of cytopathological reporting of breast lesions 2. Histopathological examination is considered the gold standard for diagnosing benign as well as malignant breast lesions 7, 8.

Breast FNAB is a rapid, accurate and highly cost-effective diagnostic procedure with a minimal complication rate for the broad spectrum of benign and malignant breast lesions. 9, 10, 11. Breast FNAB has a low false negative rate with any errors related to diagnostic difficulties with low-grade carcinomas and sampling error, and a very low false positive rate, which is usually due to misinterpretation of fibroadeno mas, intraductal papillomas and papillary lesions 12, 13. Breast FNAB in the developed world with a high level of medical resources is a component of the “triple test” comprising clinical, imaging and FNAB cytology, and the triple test has a PPV close to 100% 13, 14. So, in this study, by correlating the FNAC with histopathology wherever possible, we tried to evaluate the effectiveness of IAC Yokohama system for reporting breast cytopathology.

This was an Institution based cross-sectional study done over a period of 18 months from November 2021 to September 2022, in the Department of Pathology, Government Medical College and Dr Susheela Tiwari Government Hospital Haldwani. FNA was done using 19-24 gauge disposable sterile needle attached to a 20 ml disposable plastic syringe. Sample was aspirated and smeared on the glass slides. The air dried smears were stained with Giemsa and fixed smears with Papanicolaou stain. For histopathological evaluation, we received biopsy specimen from patients who have undergone a surgery in Department of Surgery, Government Medical College and Dr Susheela Tiwari Government Hospital Haldwani, after proper grossing and sectioning, stained the slides with H&E stain and evaluated by using Nottingham modification of Bloom-Richardson system.

Total 205 FNAC cases were collected, out of which histopathological study was done in 70 cases. 2 cases from total 16 cases of Non diagnostic Aspirate (Yokohama category I), were correlated with histopathology and came out be malignant. Benign category (Yokohama category II) showed maximum number of cases (132 cases; 64.69%). Out of which 39 cases were correlated with histopathology and showed 100% concordance with Fibroadenoma as the most common benign breast lesion (74 cases; 56.06%). Among malignant lesions (Yokohama category V), out of total 26 cases 16 cases were correlated histopathologically and showed 100% concordance. Commonest breast lesion was Ductal carcinoma (25 cases; 96.15%). Out of total 16 cases in category Suspicious for malignancy (Yokohama category IV) 4 cases were correlated with histopathology and findings came out to be concordant with histopathology. Atypical, probably benign (Yokohama category III) showed variation in diagnosis. Out of total 9 cases of the category for cytohistopathological correlation, 5 cases came out to be malignant while 4 cases turned out to be benign. The details of these lesions are in Table 1, Table 2. Risk of malignancy (ROM) was calculated which was 100% in Yokohama category I, IV and V. In Category III it was 55.5% and 00% ROM was recorded in Yokohama category II (Table 2). FNAC correlation with histopathology was significant (P Value=<0.01 & Chi square value 40.7) (Figure 1, Figure 2).

Figure 1 Figure 2

In the present study out of total 205 cases, maximum number of cases were diagnosed as benign (132; 64.39%) and minimum number of cases were in Atypical probably benign (14; 8.82%). Non diagnostic category had 16 cases (7.80%). These findings were correlated with several other studies (Table 3). In this study, Fibroadenoma (56.06%) is the commonest benign breast lesion while Ductal carcinoma (96.15%) is the commonest malignant breast lesions. Studies conducted by Bhagat and research team (44.23% cases Fibroadenoma; 84.8% Ductal carcinoma) and Deshpande with colleagues (38.3% Fibroadenoma; 75% Ductal carcinoma) were in concordance with the present study 15, 16. Cytohistopathological correlation was done in total 70 cases. Out of total, 16 cases of Non diagnostic aspirate (Yokohama category I) 2 cases were correlated with histopathology where they came out to be malignant. This could have been due to low cellularity, aspiration of blood only or false technique where aspirator might have missed the malignant focus. 39 cases of Benign (Yokohama category II), 4 cases from Suspicious for malignancy (Yokohama category IV) and 16 cases from Malignant (Yokohama category V) were correlated with histopathology and showed 100% concordance.

In Atypical probably benign (Yokohama category III) out of total 15 cases we had 9 cases for cytohistopathological correlation. Out of which 5 cases came out to be malignant while 4 cases were diagnosed as benign (Table 3). This could have been due to some cytological features that are common in benign lesions and uncommonly seen in malignant lesions. For example, one of the case from Atypical probably benign category diagnosed as colloid carcinoma breast on histopathology might have shown this disconcordance due to the nature of lesion of being showing low cellularity in a hemorrhagic background containing mucinous material also the younger age group of patients might have biased the cytological diagnoses. Based upon the findings and taking Yokohama categories I, II and III as benign and categories IV and V as malignant for statistical evaluation we calculated sensitivity as 74.07%, specificity and PPV as100%, NPV as 86% and diagnostic accuracy as 90%. The statistical parameters were correlated with several other studies (Table 5). The Risk of malignancy (ROM) was calculated as 100% for category I, 00% for category II, 55.55% for category III, and 100% for both category IV and V. These findings were correlated with several other published studies (Table 4). In study conducted by Nigam JS with colleagues we took statistical parameters of group and study population for correlation purpose 17. The chi square value and p value were 40.7 and <0.01% respectively which proves a significant correlation between cytopathological and histopathological findings. These findings were correlated with studies done by Deshpande with colleagues (p value;0.042) and Sunitha with team (p value; <0.0001 & chi square value; 83.115) and showed significant concordance 18.

Based upon the findings in present study, we found that the collaboration of FNAC with IAC Yokohama system for reporting breast cytopathology proved itself to be an effective and productive tool for guiding the surgeon and clinician for better management options by providing the clear communication regarding reporting of cytopathology and a keen eyesight about the spectrum of results that can be obtained based upon the nature of lesion and other conditions. The output for patients depends upon histopathology laboratories vary between those countries with well-developed medical infrastructure and those low- and middle-income countries with more limited resources. Finally, the IAC Yokohama System will invoke a response from the cytology community and also from all those who provide a component in the “triple” diagnostic approach, which is the best practice for women with breast lesions. This will lead to continuing improvements in the care of patients with breast lesions and possible modifications to the IAC Yokohama System.

I am thankful to Surgery department, Obstetrics and Gynaecology department and Radio diagnosis department for given patient’s information and samples for this study. I appreciate principal, Government Medical College, Haldwani, Nainital, Uttarakhand for their support for this study.

Declaration of patient consent: The authors certify that they have obtained all appropriate patient consent forms.

Conflicts of interest: There are no conflicts of interest.

Ethical approval: The study was approved by the Institutional Ethics Committee.