Malignant microcalcification: prediction of excision margins by separating calcified and noncalcified core biopsies

Introduction

Suspicious microcalcification is investigated by vacuum-assisted core biopsy. Many patients, in whom malignancy is diagnosed, go on to have breast-conserving surgery where positive resection margins require re-operation. The aim of this study was to determine whether there is an increased risk of positive margins when malignancy is identified in cores without microcalcification.

Methods

In this institute, core biopsy samples are separated into those containing calcification and those not. Sixty-eight consecutive patients undergoing breast-conserving surgery were selected. From the histology report, the presence of malignancy in each group of cores was recorded. The adequacy of margins following the local excision and the need for re-operation was then analysed.

Results

Sixty-eight patients were included in the study. The mean age at diagnosis was 56.7 (range 40 to 77). All 68 patients had malignancy in the cores containing calcification. Twenty-three (34%) patients had malignancy in these cores alone and nine (39%) of these patients required further surgery. Forty-five patients had malignancy in both of the sets of cores, 24 (53%) required further surgery for inadequate margins. Although there is a difference between the re-operation rate, this is not statistically significant (P = 0.3124, Fisher’s exact test).

Conclusions

Malignancy is commonly diagnosed in cores that do not contain microcalcification. Although there appears to be a higher rate of inadequate margins in this group (53% vs. 39%), in this study the difference was not statistically significant. Following the findings of this initial study, we are now increasing the sample size of the group.