Stereotaxic localisation and aspiration cytology of impalpable breast lesions.

As part of a programme of assessment of the 'Sterotix' localisation device, aspiration cytology was carried out on 50 patients with 52 impalpable, mammographically detected breast lesions using the stereotaxic guidance device. This was followed by an open localisation biopsy of the area for confirmation. In 12 patients (23%) the aspirations failed to yield sufficient material for diagnosis. This was frequently due to the poorly cellular nature or very small size of the lesions. Of the remaining 40 patients, 15 were regarded as having both mammographically and cytologically benign changes which were confirmed histologically; they could thus have been spared diagnostic surgery. Ten patients had a diagnosis of malignancy with both investigations, and could have had planned investigation and subsequent definitive surgery. Of the remainder, 14 lesions had a report of malignancy or suspicion of it with either technique and these patients would have come to conventional localisation biopsy. Only one patient was found to have a malignancy, who had cytologically benign and mammographically 'probably benign' disease: this was an invasive lobular carcinoma with a dominant in-situ component and may well have been an incidental finding on biopsy.