US-elastography in the differential diagnosis of benign and malign breast lesions and histopathologic correlation

Purpose: Ultrasonographic elastography is a highly specific, noninvasive complementary method utilized for determining the stiffness of a tissue, and for reducing the benign tumor biopsies employed due to the specificity of conventional ultrasonography. The aim of this study was to compare the findings of elastography with histolopathologic findings in the characterization of breast masses. Material and Methods: 533 lesions were evaluated in 377 patients with breast lesion. Their ages were between 12-83 years (mean 46). Three hundred seventy five of them were female and two of them were male. All patients were evaluated with gray scale US, elastography by using Siemens Acuson Antares with elastography software 13-8 MHz transducer equipment. All images were recorded digitally. Cytological / histopathological diagnosis was obtained for all BIRADS 4 and 5 lesions. The elasticity scores of the lesions were: Score 1: Elasticity in entire lesion, Score 2: Less than %45 of lesion was inelastic (red), Score 3: More than %45 of lesion was inelastic (red), Score 4: Almost whole lesion was inelastic (red), Score 5: Completely inelastic lesion. Also the lesions were evaluated by the means of number, size, echogenity, inner structure ,presence perifpheral halo, border property, shape, transverse diameter ratio of ap and location (location based on skin). Elasticity scores and mean strain ratios of all lesions were compared with their pathologic diagnosis and BIRADS category. Also, age of patients associated with breast cancer was evaluated statistically. Findings: According to BIRADS lexicon BIRADS 2 and 3 were considered to be benign, BIRADS 4 and 5lesions were malign lesions. 258 of a total of 533 lesions were BIRADS 2 and 3, 375 of lesions were BIRADS and 5 . Considering Elasto scores of lesions; score of 1, 2 and 3 were categorized as benign lesions scores 4 and 5 were categorized as malignant lesions. The number of lesions with score 1 were 10, score 2 were126, score 3 were 124, score 4 were 200 and score 5 were 73. Nine of ten lesions with Score 1 elasticity were benign, one was a necrotic malignancy.. One hundred thirteen lesions with Score 2 elasticity were benign and thirteen were malignant. Eight of them were necrotic. One hundred ten lesions with Score 3 elasticity were benign and fourteen were malignant. Three of the malignant lesions were necrotic. Fourty six lesions with Score 4 elasticity were benign and one hundred fifty four of them were malignant. There were seventy three lesions with Score 5 elasticity. . Twelve of them were benign, others were malignant. In differantion between benign and malignant breast masses sensitivity, and specificity, PPV and NPV of BIRADS were calculated as %98,3 , % 72 ,% 64 and % 92,7 for US and %84,4, %65 ,%55,3 and %89,2 for elastography scoring system respectively Conclusion: US-elastography is an assisting imaging technique to B-mode ultrasonography Key words: Elastography, breast lesions, elastography score, biopsy