RESUMO
OBJECTIVE: Ultrasonography is invaluable for evaluation of palpable masses and masses detected by mammography. Ultrasound has no proved role in breast screening. Between 1991 and 1994, we included ultrasonography routinely in our screening mammography prescription, not only for evaluation of mass detected by mammography but also in radiographically dense, non-radiolucent breast. One hundred and thirty-seven suspicious but non palpable breast lesions were detected. We analyzed the results of the surgical excision biopsies of these lesions and evaluated the contribution of ultrasonography combined with mammography to detect occult breast cancers. MATERIAL AND METHODS: From 1991 to 1994, our institution performed 8,489 individual screening mammographies. All women underwent physical examination before mammography. Women with abnormal clinical breast examination are not included in the study. Ultrasonography was routinely performed for characterization of a mass detected by mammography and also in normal breast with dense, non-radiolucent tissue. One hundred and thirty-seven suspected breast lesions were removed after immediate preoperative stereotaxic or US-guided needle localization. Screened women were aged 29-72 years (mean 51 years). 48% of all screened women were aged 50 years and older. RESULTS: The histopathologic findings were as follow: invasive ductal carcinoma (IDC) 40 cases (59%), invasive lobular carcinoma (ILC) 7 cases (10%), ductal carcinoma in situ 21 cases (31%). Infracllnic cancer was identified by mammography alone in 45% of cases, by mammography and sonography in 43.2% of cases, by sonography alone in 11.8% of cases. About 31% of infraclinic cancer occur prior to the age of 50 (age range: 29-72, mean: 54). Cancer less than 10 mm in diameter were found in 57.5% of lesions. Axillary dissection was performed in 46 cases of invasive cancer, with a incidence of axillary node metastases of 15%. CONCLUSION: The combination of mammography and ultrasonography is effective to detect a greater number of occult breast cancers and we recommend ultrasonography not only for evaluation of a mass detected by mammography but also in radiographically dense non-radiolucent breast lesions.