[Diagnostic accuracy of the fine needle aspiration cytology and core needle biopsy as a diagnostic method for breast lesions].

PURPOSE: to determine the accuracy of fine-needle aspiration biopsy (FNAB) and of core-needle biopsy (CNB) in diagnosing breast lumps and breast cancer.

METHODS: this was a cross-sectional, retrospective and descriptive study based on the review of medical records. FNAB and CNB were carried out sequentially according to the routine of the Mastology Service. Both percutaneous procedures were applied to 233 patients during the period from March 2005 to February 2007. Women aged 18 years or more with changes in the clinical and/or image examination of the breast or a family history of breast and/or ovarian cancer were included. FNAB and CNB were carried out according to the technical recommendations of the National Institute of Cancer. The percentage of agreement, Cohen's Kappa coefficient, sensitivity, specificity, positive and negative predictive values and the accuracy of FNAB and CNB were calculated, considering the surgical biopsy as the gold standard.

RESULTS: the average age of the patients was 49.0 years (±12.7) and the tumors measured 26.9 mm on average (±23.1), being larger than 20 mm in 47.2% of cases. Sensitivity, specificity, positive and negative predictive values and accuracy were higher for CNB than for FNAB, regardless of the size of the breast lesion. The diagnostic accuracy was 97.5% for CNB and 77.5% for FNAB.

CONCLUSION: although the CNB showed higher rates of sensitivity, specificity, positive predictive value, negative predictive value and accuracy than FNAB for palpable and non-palpable breast lumps, the method remains useful for the minimally invasive diagnosis of mammary lesions, especially when its results are analyzed together with the clinical and imaging examination.