Diagnostic utility of the Yokohama system in reporting cytology of breast lesions

Background

Breast lesions are considerably more common in females than in males and most frequently present as palpable lumps. Histopathological analysis indicates fibrocystic change as the predominant finding followed by cases without significant pathology miscellaneous benign lesions and fibroadenoma. Broadly breast lesions are classified into benign and malignant categories. Among malignant lesions breast carcinoma remains the leading cancer in Indian women with an estimated incidence of 26 per 100000 and a mortality rate of 13 per 100000 women. According to GLOBOCAN 2024 breast cancer accounts for 135 percent of all cancers and 106 percent of cancer related deaths in India with a cumulative lifetime risk of 281 percent. Given its position as the most common malignancy in women globally as well as nationally early detection and diagnosis of palpable breast lumps are essential for timely initiation of appropriate therapy.

Fine needle aspiration cytology FNAC has become a frontline diagnostic modality owing to its simplicity cost effectiveness and minimally invasive nature. Conducted in the outpatient setting FNAC when combined with clinical and radiological assessment allows efficient triaging of breast lesions reducing the need for invasive diagnostic procedures without delaying treatment in malignant cases. Its utility is especially significant in resource limited settings. Additionally aspirated material can be processed into cell blocks enabling ancillary studies and expanding diagnostic accuracy.

To establish uniformity in reporting the International Academy of Cytology IAC introduced the Yokohama System in 2016. Developed through collaboration between cytopathologists surgeons oncologists and radiologists this standardized five tier classification links cytological categories with their corresponding risk of malignancy ROM and clinical management pathways. The categories include insufficientinadequate benign atypical suspicious of malignancy and malignant. By providing consistent terminology and aligning reporting with management algorithms the Yokohama system enhances diagnostic reproducibility improves interdisciplinary communication and supports optimal patient care.

Methodology

This is a laboratory based prospective observational study proposed for two years November 2023 to November 2025 in the Histopathology and Immunohistochemistry division of the Department of Pathology Jawaharlal Nehru Medical College Sawangi Meghe in collaboration with the Department of General Surgery Acharya Vinoba Bhave Rural Hospital Sawangi Meghe. Institutional Ethics Committee approval will be obtained prior to commencement and informed consent will be secured from all participants.

Conclusion

All breast FNA smears will be evaluated and reported using the IAC Yokohama system as follows

Category 1 Inadequate eg blood only non representative material Category 2 Benign eg fibroadenoma breast abscess Category 3 Atypical presence of atypical cells Category 4 Suspicious of malignancy Category 5 Malignant