seroma
(see-ROH-muh)
A mass or lump caused by a buildup of clear fluid in a tissue, organ, or body cavity. It usually goes away on its own but may need to be drained with a needle. It  often occurs after breast surgery.
The NIH Clinical Center (the research hospital of NIH) is open. For more details about its operating status, please visit cc.nih.gov.
Updates regarding government operating status and resumption of normal operations can be found at opm.gov.