Ace the MedCa Medical Assistant Exam 2026 – Boost Your Medical Marvel Skills!

A brain tumor is classified as a mass of abnormal cells that grow uncontrollably in the brain. The term "abnormal" refers to the changes that occur in the cells, which deviate from the normal, healthy structure and function. These abnormal cells can originate from the brain tissue itself (primary brain tumors) or from other parts of the body that metastasize to the brain (secondary brain tumors). In the context of brain tumors, these cells can exhibit characteristics such as rapid proliferation and the ability to invade nearby tissues, distinguishing them from normal, healthy cells.

While healthy cells, blood cells, and nerve cells may all play roles in the brain's physiology, they do not define the makeup of a brain tumor. Instead, it is the abnormal cells that are responsible for the tumor's presence and its potential to affect the function and health of the surrounding brain tissue. Understanding that brain tumors consist primarily of abnormal cells is crucial for grasping how they impact the body and the treatment strategies that may be employed to address them.