Pitfalls of Contrast Enhanced Ultrasound (CEUS) in determination of breast tumor biological dignity.

The aim of this prospective study was to identify characteristics of breast lesions on contrast enhanced ultrasound (CEUS) that can be a source of diagnostic ambiguity and cause under- or overestimation of examined breast lesions. 215 women (range 23-76 y., mean age 53.16 y) with 215 breast lesions were examined by B-mode ultrasound, followed by CEUS and core biopsy. CEUS parameters: degree of opacification, character of washout and preliminary CEUS result (suspicious, non-suspicious, uncertain) were subsequently correlated with histopathological outcomes. Observed qualitative variables, CEUS results and their analysis with respect to histological type were evaluated using Pearson χ2 square test, p<0.05 was statistically significant. Differences in mean lesion size, mean age of patients, mean size between groups (malignant/benign) with respect to CEUS result were evaluated by t-test. 215 tumors, 116 (53.93%) benign and 99 (46.05%) malignant lesions. 17 (14.66%) benign and 15 (15.15%) malignant lesions expressed atypical washout, 5 (4.31%) benign lesions had early washout and 38 (38.38%) had continuous washout (p<0.0001). 56 (48.28%) benign and 55 (55.56%) malignant lesions had middle degree of opacification, 19 (16.38%) benign had high and 5 (5.05%) malignant lesions low degree of opacification (p<0.0001). Finally, 38 (32.72%) benign and 20 (20.20%) malignant were marked CEUS uncertain. As risk lesions are considered fibroadenomas, fibrocystic lesions, papillomas and low grade DCIS or invasive breast tumors, especially lesions smaller than 10 mm.Identification of CEUS pitfalls with respect to problematic histopathologic entities can reduce the risk of misdiagnosis and improve further management of breast lesions.