Which description best characterizes a breast cyst on examination?

• A. Irregular, hard, fixed, non-mobile
• B. Round, soft to firm, elastic, well-delineated, mobile, and tender
• C. Small, painless, fixed
• D. Disk-shaped, hard, non-tender

Answer: (B)

Breast cysts are benign, fluid-filled lesions that typically feel smooth and well defined on examination. They are usually round and have a well-circumscribed border because the fluid-filled cavity creates a clearly demarcated mass. The contents are compressible, giving the mass an elastic feel. Because the cyst is within the breast tissue and not adherent to the chest wall or skin, it is generally mobile rather than fixed. Tenderness is common, especially with larger cysts or around hormonal fluctuations, such as before or during menses.

These features help distinguish a cyst from masses that raise more concern for cancer, which are typically irregular in shape, harder, and fixed or tethered to surrounding tissue. So the description that best fits a breast cyst on exam is a round, soft to firm, elastic, well-delineated, mobile, and tender mass.