Palpable breast thickening: Role of mammography and US in cancer detection

PURPOSE: To determine the frequency of breast carcinoma and ascertain the diagnostic yield of mammography and breast ultrasonography (US) in the detection of breast carcinoma in women with palpable breast thickening. MATERIALS AND METHODS: One hundred twenty-three consecutive cases of breast thickening (103 patients) during a 1-year period were reviewed. Experienced breast examiners prospectively identified patients with breast thickening. Results of diagnostic mammographic work-up, breast US, breast biopsy, and clinical follow-up were retrospectively reviewed. RESULTS: Six (5%) of 123 cases had a diagnosis of breast carcinoma; five (83%) of the six had invasive carcinoma. Mammography was performed in all cases, US in 77 (63%) cases. Mammographic sensitivity for invasive cancer detection was 60% (three of five cases), specificity was 94% (102 of 108 cases), and negative predictive value was 97% (102 of 105 cases). Sensitivity of US alone was 100% (two of two cases), specificity was 96% (65 of 68 cases), and negative predictive value was 100% (65 of 65 cases). The combined negative predictive value of mammography and US was 100%. Patients with prior biopsies at the site of palpable thickening accounted for most false-negative mammograms. Median time to initiate follow-up of patients in whom biopsy was not performed was 14 months. CONCLUSION: Breast cancer was discovered in 5% of women with palpable breast thickening. Women with negative mammograms and US scans are at low risk for cancer but should, in our opinion, be followed up at short-term intervals with clinical examination and imaging if biopsy is not elected by their surgeon or clinician. (C) RSNA, 2002.