Microcalcification and its relationship to cancer of the breast: experience in a screening clinic.

The mammograms and specimen radiographs of 45 women in whom the presence of microcalcification played a major part in the decision to biopsy, were studied to determine possible distinguishing features. A mammographic lesion of 150 mm2 or less with an irregular density and five or more calcific particles, especially if palpable, was very likely to be an invasive carcinoma. With improved resolution, it should become possible to distinguish those calcifications covering 150 mm2 or less in the mammograms which are associated with parenchymal structures and those that are associated with stromal elements. Features that may potentially distinguish some benign parenchymal calcifications and those parenchymal calcifications associated with non-invasive malignancy are described. There will probably remain a few benign parenchymal associated calcifications which are identical to the calcifications associated with non-invasive cancer. Implications for improvement in technique are considered.