How is a meningioma typically characterized in terms of its spread?

A meningioma is typically characterized as encapsulated and non-invasive. This means that it usually grows within the meninges, the protective membranes that cover the brain and spinal cord, often maintaining a distinct boundary from the surrounding brain tissue. The encapsulated nature of meningiomas allows them to be removed surgically with relative ease compared to more invasive tumors, which can infiltrate nearby brain structures. Additionally, meningiomas usually do not spread to other parts of the body, which is in contrast to metastatic tumors that originate elsewhere and spread through the bloodstream or lymphatic system.

Understanding the encapsulated and non-invasive nature is crucial for diagnosis, surgical planning, and predicting the biological behavior of the tumor. This characteristic is particularly significant because it helps inform treatment decisions and the prognosis for individuals diagnosed with meningiomas.