Clinical management of nonpalpable or small breast masses by fine-needle aspiration biopsy (FNAB) under ultrasound guidance.

Abstract

Open breast biopsy of palpable breast masses is widely accepted. Now, the use of high-resolution, real-time ultrasound (US) makes it easy to detect nonpalpable or small breast nodules, as well as palpable breast masses. We performed fine-needle aspiration biopsy (FNAB) under US guidance to manage the nonpalpable or small breast masses detected by US examination and to distinguish between benign and malignant tumors. To investigate the usefulness and sensitivity of FNAB under US guidance, we reviewed a total of 137 FNAB records for cases diagnosed between January 1993 and December 1994. Fifty-five cases were classified as benign, 70 as atypical/indeterminate, 1 as suspicious/probably malignant, 6 as malignant, and 5 as unsatisfactory. Of these, five cases were confirmed as malignant, but one case showed no malignancy at surgery. Four cases were nonpalpable breast cancer, two were in stage 0, and two were in stage I. One case in the suspicious/probably malignant group on the initial FNAB was shown to be malignant by re-aspiration on follow-up study. The sensitivity of FNAB under US guidance was 83.3% (5/6) and the specificity was 99.2% (125/126). The diagnostic accuracy was 83.3% (5/6) and the negative predictive value was 99.2% (125/126). FNAB under US guidance is useful for the management of nonpalpable or small breast masses; it is sensitive for distinguishing between benign and malignant tumors and may reduce unnecessary surgical procedures and replace conventional manual aspiration biopsy.