What is a hematoma?

A hematoma is defined as a localized collection of blood outside of blood vessels. This occurs when blood vessels are damaged and blood leaks into surrounding tissues, leading to pooling and clumping of blood. Hematomas can vary in size and severity, often developing as a result of trauma or injury that disrupts the integrity of blood vessels. They can occur in various parts of the body, including the brain, where they may require medical attention depending on the extent and location of the bleeding.

In the context of the other options, a type of skull fracture refers to a specific injury involving the bones of the skull, whereas a severe brain injury indicates significant damage to brain tissue, which is distinct from the accumulation of blood. An infection of the meninges relates to conditions like meningitis, which involves inflammatory processes rather than blood collection. Therefore, the definition of a hematoma as a localized accumulation of blood stands out as the most accurate and relevant answer in this context.