Efforts directed at early detection of breast cancer have resulted in an increased incidence of nonpalpable mammographic lesions that warrant excisional biopsy. The most common localization method is the needle-localization biopsy. The aims of this study were to evaluate the effectiveness and the usefulness of needle-localization biopsy in the diagnostic workup of nonpalpable mammographic abnormalities that are suspected of being cancerous, and to determine the frequency of malignancy detection and the incidence of noninvasive carcinoma.

One hundred seventy eight needle-localization biopsies of nonpalpable breast lesions were performed at Samsung Medical Center from January 1995 to December 1999. A retrospective review was undertaken to assess histopathologic findings based on mammographic abnormalities, as well as the pathologic staging and the treatment of breast cancer detected by needle-localization biopsy.

Needle-localization biopsies led to the diagnosis of malignancy in 29.8% of the biopsies. Of the malignancies detected, 81.2% were in-situ carcinoma. Invasive carcinoma were less than 2cm in size(TI) in 70% of the cases and were 2 to 5cm(T2) in 30% of the cases; there were no evidence of lymph node metastases in 70% of the cases. Overall, 90.6% of the patients were found to be within pathologic stage 0 or stage 1. Microcalcifications only were more related with DCIS than mass density with or without microcalcifications findings. Fine linear, branching, granular, pleomorphic microcalcifications findings and ill defined, irregular, spiculated mass densities were likely to result in higher rate of malignancy.

It is concluded that needle-localization breast biopsy of nonpalpable suspicious mammographic lesions is an important and effective method for the detection of early breast cancer and noninvasive carcinomas. Appropriate selection of cases for needle localization biopsy should be made to avoid unnecessary breast biopsies and to increase the percentage of early breast cancer.