Nonpalpable Breast Lesions At Biopsy: A Detailed Analysis of Radiographie Features

Several studies have demonstrated that mammographie screening of asymptomatic women results in a lower mortality rate where breast cancer is concerned. Often, screening mam-mograms reveal a nonpalpable radiographie abnormality and the diagnosis must be determined by an excisional biopsy after radiographie needle localization. The mammographie features associated with 179 nonpalpable breast abnormalities biopsied after radiographie needle localization were carefully characterized. There were 41 carcinomas (23%) in the series. The aim of this study was to determine which radiographie findings, if any, strongly portend the presence of either a malignant or benign lesion. Mammographie features that were commonly associated with malignancy include a change from a previous mammogram, a distortion of the surrounding architecture, the association of a soft tissue density and calcifications, and the presence of more than ten calcifications in the lesion. The radiographie abnormalities which were more commonly associated with benign disease include well-defined densities without calcifications, asymmetric densities without calcifications, and abnormalities consisting solely of a focus of mammographie calcifications that have fewer than ten concretions. The incidence of malignancy in lesions having these mammographie characteristics was only 5.5%. On the basis of these results alone, no firm threshold for biopsy can be recommended. The risks of deferring biopsy until there is worsening of the mammographie image remains to be determined.