Sonography of palpable breast cancer

Purpose. Because of the increasing use of sonography to rule out cancer in women with palpable breast abnormalities, this study was performed to deter mine the rate of sonographically occult malignancy in this clinical setting . Methods. Women who were recommended for biopsy based on mammographic and/or clinical findings underwent breast sonography. This study retrospectively analyzed the subset of patients with palpable malignant lesions. Lesions we re classified as visible or occult on mammography and sonography. Patients without a tissue diagnosis of tumor were excluded. Results. Of 1,346 masses that underwent biopsy or aspiration, 616 lesions w ere palpable, and of these, 293 were malignant. Sonography detected all 293 palpable malignant lesions (95% confidence interval for sensitivity, 99-10 0%). Eighteen lesions were mammographically occult. The median lesion size as determined by sonography was 1.8 cm; for the lesions that were mammograp hically occult, the median size was 1.6 cm. The most common histopathologic diagnosis for both groups of lesions was infiltrating ductal carcinoma. Conclusions. All palpable malignant breast lesions were visible by sonograp hy in patients in whom a biopsy was recommended. However, we caution that u ntil the false-negative rate of sonography for equivocal palpable abnormali ties is determined prospectively, sonography cannot be accurately applied t o rule out malignancy in this setting. (C) 2000 John Wiley & Sons, Inc.