Seroma

A seroma is a pocket of clear serous fluid that sometimes develops in the body after surgery. When small blood vessels are ruptured, blood plasma can seep out; inflammation caused by dying injured cells also contributes to the fluid.

Seromas are different from hematomas which contain red blood cells and from abscesses which contain pus and result from an infection.

Seromas can sometimes be caused by a new type of partial-breast radiation therapy, as explained in a recent article in the International Journal of Radiation Oncology, Biology, Physics.

Seromas can also sometimes be caused by injury such as when the initial swelling from a blow or fall does not fully subside. The remaining serous fluid causes a seroma that the body usually gradually absorbs over time (often taking many weeks); however, a knot of calcified tissue sometimes remains.

Seroma is particularly common after mastectomy surgery for breast cancer and many women find that it makes their initial recovery period more difficult. Some women need repeated visits to their doctor to have the seroma fluid drained.