Which structure is commonly evaluated for potential disease involvement in breast imaging?

• A. Lymph nodes
• B. Cooper's ligaments
• C. Pectoralis muscle
• D. Rib and chest wall muscle

Answer: (A)

Lymph nodes, especially in the axilla, are routinely evaluated because they are the most common first site for breast cancer spread. Imaging looks for signs of nodal involvement such as cortical thickening, loss of the fatty hilum, irregular contour, or enlargement. Detecting suspicious nodes informs staging and helps guide biopsy and surgical planning, including the decision for sentinel lymph node biopsy.

Cooper's ligaments are supportive structures that help maintain breast shape; they may show distortion on imaging but are not the primary target for assessing disease spread. The pectoralis muscle and rib/chest wall muscle can be involved if cancer is advanced, but involvement of these deep structures is less common and not the usual focus of initial disease assessment.