Stereotactic 14 gauge core-biopsy of the breast: Results from 101 patients

Background: Along with fine needle aspiration (FNA) cytology, core-biopsy has become an integral part of the assessment of mammographically detected breast lesions. Methods: A series of stereotactic large-core-biopsies of mammographically detected breast lesions was studied to assess the accuracy and limitations of the technique in diagnosing malignancy and in giving specific benign diagnoses, and its use in determining surgical management. Results: Eighty per cent of carcinomas were diagnosed as malignant (absolute sensitivity). In 88.8% of the cancers, the core-biopsy was classified as malignant, suspicious or atypical/indeterminate (complete sensitivity), and in 72% of the invasive carcinomas, invasive tumour was present in the core. The technique was more successful for invasive carcinomas than for ductal carcinoma in situ (DCIS) (absolute sensitivity 86.1 and 55.5, respectively; P = 0.28) and for malignant mass lesions than for a mass with associated microcalcifications or for pure microcalcifications (absolute sensitivity 91, 71 and 66.6%, respectively; P = 0.19). In five of the 45 cancers (11.1%), no tumour tissue was present in the core, but all were excised after mammographic review and no delays in diagnosis have been experienced to date. The benign to malignant ratio for excised lesions was 0.11:1. Of the benign lesions, a specific diagnosis was given in 49% (calcifications in the core in a background of fibrocystic change, or postoperative scarring, or fibro-adenoma); the remainder showed non-specific benign findings. All patients where invasive carcinoma was diagnosed in the core underwent axillary clearance and wide local excision or mastectomy at their first operation. Conclusions: This technique can markedly reduce the number of benign lesions needing open biopsy, and provide information allowing definitive management of most carcinomas at the first operation. The accuracy of core-biopsy was lower in DCIS/microcalcification lesions; extra core samples or a combination of FNA and core-biopsy may be of value in these cases.