contusion

A bruise that is usually produced by impact from a blunt object and that does not cause a break in the skin.

Injury to tissues without breakage of skin; a bruise. In a contusion, blood from the broken vessels accumulates in surrounding tissues, producing pain, swelling and tenderness. In light-colored animals a discoloration may appear as a result of blood seepage under the surface of the skin.
Serious complications may develop in some cases of contusion. Normally blood is drawn off from the bruised area in a few days, but there is a possibility that blood clotted in the area will form a cyst or calcify and require surgical treatment. The contusion may also be complicated by infection.

• cerebral c. — contusion of the brain following a head injury. It may occur with extradural or subdural collections of blood, in which case the patient may be left with neurological defects or epilepsy.