Development of malignant breast microcalcifications after neoadjuvant chemotherapy in advanced breast cancer.

The increased interest in the use of neoadjuvant chemotherapy for patients with locally advanced or large tumors at initial presentation necessitates the recognition of sequelae of this therapy. This article describes the interval appearance of malignant, linear-branching, microcalcifications during neoadjuvant chemotherapy for locally advanced breast cancer. Mammographically the malignant microcalcifications appeared only in the region of the breast where the primary tumor was found. Pathologically only a subpopulation of malignant cells responded to the chemotherapy, demonstrating viability of the majority of the tumor, with cell death only in the subpopulation. With the increased use of neoadjuvant chemotherapy, it is important to recognize previously undescribed mammographic findings secondary to this therapeutic approach.