ANALYSIS OF SONOGRAPHIC FEATURES IN THE DIFFERENTIATION OF FIBROADENOMA AND INVASIVE DUCTAL CARCINOMA

OBJECTIVE. The purpose of this study was to determine the predictive p ower of sonographic tumor descriptors in the differentiation of fibroa denoma from invasive ductal carcinoma of the breast. SUBJECTS AND METH ODS, Three hundred thirty-six tumors (142 fibroadenomas and 194 invasi ve ductal carcinomas) of the breast diagnosed using sonography were pr ospectively recorded with respect to the shape, contour, echo texture, echogenicity, sound transmission, and surrounding tissue of the tumor s. Evaluation included odds and odds ratios of single sonographic feat ures as well as sensitivity, specificity, and positive and negative pr edictive values of combinations of features. Tumor descriptors were al so evaluated using multiple logistic regression analysis after adjustm ent for age and clinical examination. RESULTS. Irregular shape and con tour, extensive hypoechogenicity, shadowing, echogenic halo, and disto rtion of surrounding tissue were the findings with the highest predict ive value of malignancy. A thin echogenic pseudocapsule was the most i mportant sonographic finding predictive of the benign nature of a soli d mass. Echo texture was of little value in the differentiation of bre ast tumors, Age and clinical examination remained important predictors in a clinically referred patient population because a palpable mass i n an elderly patient is most likely a carcinoma. We saw considerable o verlap of most sonographic features in both benign and malignant tumor s. However, using strict sonographic criteria and a combination of des criptors, we found a negative predictive value of 100% in palpable and 96% in impalpable tumors. CONCLUSION, A combination of tumor descript ors gave negative predictive values approaching 100%, allowing downgra ding of solid breast masses with a high degree of confidence, Extensiv e sonographic features analysis in patients with indeterminate clinica l and mammographic findings has the potential for downgrading a tumor and possibly obviating the need for excision in a subgroup of patients . Further investigations may provide standardization of sonographic de scriptor analysis and establishment of the combination of the most pre dictive features that would be useful in daily practice.