ABSTRACT
PURPOSE: We wanted to analyze the mammographic and clinical findings of the non-mass image-forming low echoic areas seen on breast ultrasonography (US) and investigate their pathologic results. MATERIALS AND METHODS: Sixty-nine patients with 72 non-mass image-forming low echoic areas seen on breast US and who had undergone mammography and biopsy were included in this study. The mammographic findings were divided into 2 groups: 1) the negative or probably benign group and 2) the suspicious for malignancy group. The US findings were divided into 3 groups: focal, segmental and diffuse distributions. The clinical findings were divided into 2 groups: the non-palpable and palpable groups. We investigated the pathologic results according to each group. RESULTS: Of the 72 lesions, 49 (68.1%) were benign and 23 (31.9%) were malignant. On the mammography, 42 (93.3%) of the 45 negative or probably benign findings and 7 (25.9%) of 27 suspicious for malignancy findings were pathologically benign (p < 0.001). On the US, 38 (76%) of the 50 focal distributions and 11 (52.4%) of 21 segmental distributions were benign (p = 0.090). Thirty (73.2%) of the 41 nonpalpable lesions and 19 (61.3%) of the 31 palpable lesions were benign (p = 0.609). CONCLUSIONS: A non-mass image-forming low echoic area seen on breast US was malignant at a higher rate when it was found in conjunction with suspicious mammographic finding. There was no significant correlation between the distribution of the non-mass image-forming low echoic areas on US or their palpability and the pathologic results.