US-guided 14-gauge core needle biopsy : comparsion between underestimated and accurately diagnosed breast cancer

Abstract

Purpose: The purpose of this study was to evaluate imaging features of breast cancer which was underestimated on ultrasound (US)-guided 14-gauge (14G) core needle biopsy (CNB) and analyze the clinical differences between the underestimated breast cancer and accurately diagnosed breast cancer.Materials and Methods: From Jan. 2007 to Dec. 2009, 1898 cases of US-guided 14G CNB were performed in our institute. 514 cases underwent operation after CNB. Among them, 248 cases proved to be cancer by surgical pathology. We retrospectively reviewed the lesions that were CNB results and categorized benign, high risk lesions and breast cancer. The clinical and imaging features such as mammographic and US findings were compared between underestimated breast cancer and accurately diagnosed breast cancer.Results: Of 248 cases of cancer, underestimation occurred in 18 lesions (7.2%). Among the 18 underestimated breast cancer, the CNB results were: atypical ductal hyperplasia (ADH) (n=7) and ductal carcinoma in situ (DCIS) (n=11) which were invasive ductal carcinoma (IDC) (n=2) or DCIS (n=5) and IDC in final pathology. Among the 186 accurately diagnosed breast cancer, the CNB results were: IDC (n=157) and DCIS (n=29). In comparison of underestimated and accurately diagnosed breast cancer, there was no statistical significance in presence of symptom, past history and patient’s age. However, BI-RADS category, margin of mass on mammography and US, and orientation of lesion on US revealed statistically significant difference. (p < .05). Conclusion: The underestimation rate of US-guided 14G CNB was 7.2%. Compared with correctly diagnosed breast cancer, relatively lower BI-RADS category on underestimated breast cancer was noted and margin and orientation of lesion showed significantly different values between two groups.