How does the ultrasound appearance of a breast hematoma change as it evolves?

• A. Fresh blood may be anechoic; clot becomes organized with low-level echoes; then complex and solid
• B. Hematoma remains anechoic indefinitely
• C. Hematoma becomes cystic with posterior enhancement
• D. Hematoma shifts to oil cyst

Answer: (A)

Hematoma evolution on breast ultrasound reflects how blood clotting and subsequent organization change the internal texture of the collection over time. Right after bleeding, the fluid can be anechoic because it’s still largely liquid. As clot forms, the collection develops low-level echoes from fibrin and densely packed blood products, sometimes with internal septations. As the hematoma organizes further, it becomes more heterogeneous with debris and irregular internal architecture, giving a complex appearance. Eventually, it can look more solid as the clot stabilizes and fibrosis or scarring develops. This progression from anechoic to low-level echoes, then to complex and solid is the classic pattern for a evolving hematoma.

Other patterns, like remaining purely anechoic indefinitely, cystic appearance with posterior enhancement, or shifting toward an oil cyst, don’t fit the usual sequence of clot formation and organization in a breast hematoma.