Abstract: Objective To observe the ultrasonographic features of chest wall newly developed benign mass after mastectomy for breast cancer Methods The ultrasonographic features, clinical and histopathological characteristics of 19 patients with chest wall newly developed benign mass after mastectomy confirmed histopathologically were retrospectively reviewed. Results The postoperative time of 19 patients with chest wall newly developed benign nodule after mastectomy ranged from 3 months to 10 years and 73.7% (14/19) occured within 2 years after mastectomy. The size of the 24 lesions ranged from 5.4 mm to 114.7mm. Confirmed by postoperative pathologic diagnosis: 45.8% (11/24) for fat necrosis, 33.3% (8/24) for inflammation and foreign body giant cell reaction, the other 20.9% (5/24). Preoperative ultrasonography correctly suggested that 11 (11/24, 45.8%) chest wall lesions would be benign lesions, including 4 fat necrosis, 5 inflammation and foreign body giant cell reaction, 1 lipoma and 1 fibrous and fat tissue of inflammation. On ultrasonography, 2 lesions of fat necrosis showed hypoechoic or anechoic, regular shape, clear boundary and no blood flow signal, 2 lesions of fat necrosis showed hypoechoic, irregular shape, indistinct margin, visible in hyperechoic or calcification, no blood flow signal. Five lesions for Inflammation and foreign body giant cell reaction showed that 3 lesions had significant posterior echo attenuation, 2 lesions were hyperechoic, 5 lesions had little or no blood flow signal. One lesion for lipoma and 1 lesion for fibrous and fat tissue of inflammation showed hyperechoic. Conclusions The chest wall newly developed benign mass often occured within 2 years after mastectomy. The pathological type is complex, but often for fat necrosis and inflammation and foreign body giant cell reaction. The sonographic features are varied and the diagnosis still depends on histopathology.

Key words: 【Key words】 Ultrasonography, Breast neoplasms, chest wall benign mass