STEREOTAXIC 14-GAUGE CORE-BIOPSY OF THE BREAST - RESULTS FROM 101 PATIENTS

Background: Along with fine needle aspiration (FNA) cytology, core-bio psy 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 as sess the accuracy and limitations of the technique in diagnosing malig nancy and in giving specific benign diagnoses, and its use in determin ing surgical management. Results: Eighty per cent of carcinomas were d iagnosed as malignant (absolute sensitivity). In 88.8% of the cancers, the core-biopsy was classified as malignant, suspicious or atypical/i ndeterminate (complete sensitivity), and in 72% of the invasive carcin omas, 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 microcalci fications 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% (calcifi cations in the core in a background of fibrocystic change, or postoper ative scarring, or fibro-adenoma); the remainder showed non-specific b enign findings. All patients where invasive carcinoma was diagnosed in the core underwent axillary clearance and wide local excision or mast ectomy at their first operation. Conclusions: This technique can marke dly reduce the number of benign lesions needing open biopsy, and provi de information allowing definitive management of most carcinomas at th e first operation. The accuracy of core-biopsy was lower in DCIS/micro calcification lesions; extra core samples or a combination of FNA and core-biopsy may be of value in these cases.