Ultrasonographic findings of pure mucinous carcinoma of the breast

To identify the ultrasonographic findings characteristic of pure mucinous carcinoma of the breast. We reviewed the sonographic findings of 18 nodules in 15 patients which were diagnosed as pure mucinous breast carcinoma during surgery from January, 1995 to May, 2003. We analyzed the location, size, shape, orientation, margin, lesion boundary, echo pattern, and posterior acoustic features of the nodules, as well as changes of the surrounding tissue, associated calcification, axillary lymph nodes, and cystic changes in the tumor masses. All the patients were female. We also analyzed the preoperative mammographic findings of the 8 nodules that were available. The upper inner or upper outer quadrants of the breast were the most common involved sites. The longest diameter of the tumors was between 0.6 and 5.4 (mean, 2.1) cm. The ovoid shape was most frequently found(n=14), followed by round (n=2) and, irregular (n=2) shapes. Tumor margins were more commonly well-demarcated(n=10), followed by obscured (n=8) margins. Most lesions had parallel orientations (n=16) and abruptinterfaces (n=12). The internal echogenicity was most commonly complex (n=9) followed by hypoechogenicity(n=6). Most masses showed posterior acoustic enhancement (n=16), associated with posterior acoustic shadowing in 5 cases. Associated architectural distortion was seen in 3 cases. Microcalcification was associated in 3 cases. Enlarged axillary lymph nodes were associated in 2 cases. Nine masses showed cystic change in the mass. On mammography, the masses were mostly well-defined (n=3) or obscured (n=3) or, ovoid (n=6) or of a high density (n=5). On sonography, most mucinous breast carcinoma presented as a well-demarcated ovoid complex echoic mass with cystic change, and these characteristics were associated with posterior acoustic enhancement and abrupt interface.