A worrying dance in the subcutaneous adipose tissue

A 37-year-old woman presented to the emergency department with a mild painful swelling in the anterior abdominal wall at the right iliac fossa; there was no associated itching or rash. Five months earlier she underwent right mastectomy for infiltrating ductal carcinoma, which was still under treatment with chemotherapy (doxorubicin, cyclophosphamide, paclitaxel, pertuzumab and trastuzumab). Her vital signs and blood exams were normal. Ultrasonography (US) showed a 8 x 5 mm sized anechoic lesion with multiple internal thin structures, which presented parallel echogenic borders and anechoic centers, in the subcutaneous adipose tissue (Figure 1, red arrow). These structures exhibited wriggling motion during real-time imaging (Video 1).