Definition: A seroma is a fluid-filled lump that forms after surgery or tissue trauma. The fluid is clear and straw-colored; plasma seepage from blood vessels. Seromas are not usually painful, and are commonly found in areas of friction and movement after a surgery or injury. Seromas are different than other common fluid-filled lumps such as hematomas (blood-filled) or abscesses (pus-filled infection).
A seroma formed under the incision, but resorbed in a couple weeks without intervention.