Arachnoid cysts are collections of CSF localized with the arachnoid membranes. They are extra-axial by definition. They are more prevalent in males and mostly present in the pediatric population. Arachnoid cysts can present in many different locations.
What is a secondary arachnoid cyst?
Arachnoid cysts that develop later in life are called secondary arachnoid cysts. These are not brain tumors, but are rather benign sacs usually filled with clear cerebrospinal fluid (CSF). There are three layers of tissue that surround the brain and spinal cord.
What does arachnoid cyst look like on MRI?
MRI of spinal arachnoid cysts demonstrates an oval, sharply demarcated extramedullary mass that may cause local displacement and/or spinal cord compression. The cyst is usually hyperintense to CSF on T2-weighted sequences because of the relative lack of CSF pulsation artifacts.
What fluid is in an arachnoid cyst?
Arachnoid cysts are cerebrospinal fluid-filled sacs that are located between the brain or spinal cord and the arachnoid membrane, one of the three membranes that cover the brain and spinal cord.
How do you treat arachnoid cyst?
Most arachnoid cysts are stable and do not require treatment. They are four times more common in boys than in girls. Arachnoid cysts are diagnosed with a CT or MRI scan. Treatment, if necessary, involves draining the fluid through surgery or shunting.