What is an arachnoid cyst? Arachnoid cysts are the most common type of brain cyst. They are often congenital, or present at birth (primary arachnoid cysts). Head injury or trauma can also result in a ...

What often begins with early stage bumps resembling pimples or blackheads progresses into painful abscesses, nodules, and cysts, which can break open and ooze unpleasant-smelling liquid, and also ...