Background: Breast microcalcifications are difficult to depict by ultrasound (US). However, recent advances in US equipment and the refinement of breast imaging techniques have improved the detection and characterization of small breast lesions. The present study attempts to determine whether US examination is able to demonstrate nonpalpable breast lesions associated with mammographically detected microcalcifications without mass density or distortion, and to evaluate the clinical reliability of US-guided procedures, especially in cases of ductal carcinoma in situ(DCIS)of the breast.
Methods: The subjects consisted of 73 patients with breast cancer diagnosed preoperatively as DCIS by stereotactic core needle biopsies, all of whom had microcalcifications without other abnormalities on mammography. The radiological appearance and size of the clustered microcalcifications were evaluated. US examinations were performed preoperatively, and the detection rates were assessed. Sonographically detected lesions underwent US-guided wire localization followed by surgical excision.
Results: The lesions associated with microcalcifications were identified sonographically in 54 of 73 cases (74%), and the pathological examination revealed breast cancer in all of the corresponding specimens. Lesions with linear-branching shape, segmental-linear distribution and category-5 calcifications on mammography had a high level of visibility on US. The US visible cases had a larger size of calcified area on mammography when compared with US invisible cases. Pathologically, the lesions were more frequently seen on US in cases with minimally invasive cancer or with comedo type DCIS.
Conclusions: US examination is an effective method for identifying and localizing breast microcalcifications, and can be used as an alternative to stereotactic localization in selected patients with early breast cancer.