Choroid plexus papilloma (CPP) is a rare type of brain tumor. It's generally slow growing and not cancer (benign). Benign also means that the growth doesn't spread to other parts of the body. CPP is most common in young children, but it can also appear in adults.

A CPP tumor grows in the choroid plexus. This is a layer of tissue within the brain that makes the cerebrospinal fluid (CSF). CSF surrounds and cushions the brain and spinal cord. The choroid plexus lines the ventricles of your brain, which store the CSF. The choroid plexus is made of connective tissue, blood vessels, and the ependymal cells.

In adults, CPP tends to form in the fourth ventricle. In children, it forms on the lateral ventricle. The fourth ventricle is in between the cerebellum and the brainstem. The cerebellum is the part of your brain that controls your balance and coordination. The brainstem controls your breathing, swallowing, eye movements, and other vital functions.

CPP may cause your brain to make too much CSF. It might also block the normal drainage of CSF. This excess CSF in the brain (hydrocephalus) can create pressure in the brain that can be dangerous.

Even if a CPP isn't cancer, it can still cause problems. It may press against brain tissue and cause symptoms, such as headache, vision problems, or nausea and vomiting. The standard treatment for CPP is surgery to remove the tumor.

It's not yet known what causes CPP. It's possible that certain infections, genetic factors, immune system problems, or environmental factors play a role in causing these tumors. In some cases, CPP may be linked with certain rare gene changes (mutations).

CPP most often leads to increased pressure in the brain. This can cause symptoms, such as:

• Headache (common).
• Nausea and vomiting.
• Sleepiness.
• Eye problems.
• Dizziness and balance problems.
• Trouble walking.
• Seizures (rare).

Your symptoms may be different, depending on the location of the CPP tumor in your brain. Your symptoms may start slowly and get worse over time.

Your doctor may refer you to a neurologist. This is a doctor who specializes in diagnosing and treating diseases of the central nervous system. You may see a neuro-oncologist. This is a doctor who specializes in cancers of the brain and spinal cord. You may be referred to a neurosurgeon. This is a surgeon who performs brain or spinal cord surgery.

Diagnosis starts with a medical history and a physical exam. Your doctor will ask about your symptoms and past medical conditions. They may also ask about your family's medical history. The physical exam may include a neurologic exam. The doctor may ask you to do things like walk, touch your finger to your nose, or hold your hands out. They may look in your eyes with a light. Tests may be done, such as:

• CT scan. This is an imaging test that uses X-rays and a computer to make detailed images of the body. Scans may be done of your brain.
• MRI. This test uses large magnets and a computer to create images of the body. It does not use X-rays. MRI scans of your brain may be done to get more information. Contrast dye may be used to help show more detail in the images.
• Biopsy. Small pieces of tissue are taken from the tumor. They're looked at with a microscope in a lab.

The main treatment for CPP is surgery. Complete removal of the tumor with surgery usually cures CPP. These tumors rarely come back. In most cases, people have a good outcome after surgery.

If a CPP tumor is only partly removed, it may grow again, but it isn't likely to spread. An atypical CPP is more likely to come back after treatment. If CPP does come back, you may need more surgery. You may also need chemotherapy or radiation therapy to treat it.

You'll need to work with your care team to decide on the best treatment plan for you. You'll need to have ongoing follow-up with your doctor. This will include repeated imaging tests to check if the tumor comes back.

Fluid in the brain (hydrocephalus) is a common complication. This is because CPP happens in the ventricles of the brain filled with CSF. You may need a tube to drain excess CSF and lower the pressure in your brain. After the tumor is removed, this problem will likely go away.

In rare cases, there may be problems from the surgery. For example, there's a very small chance of a problem with the facial nerve. This could cause paralysis of part of your face. This is a rare problem.

• CPP is a rare type of brain tumor. It's often benign (not cancerous).
• CPP is most common in young children, but it can also appear in adults.
• CPP develops in the choroid plexus. This is the part of your brain that makes CSF. In adults, CPP most often happens near the back of the brain.
• CPP is a slow-growing tumor.
• CPP may cause too much CSF to build up in your brain (hydrocephalus). This may lead to harmful pressure within your brain.
• Surgery can usually cure this type of tumor.
• You will need ongoing follow-up with your doctor. This will include repeated imaging tests to check if the tumor comes back.
• Most people with CPP have a good outcome with treatment if all of the tumor can be removed.

Tips to help you get the most from a visit to your doctor:

• Know the reason for your visit and what you want to happen.
• Before your visit, write down questions you want answered.
• Bring someone with you to help you ask questions and remember what your provider tells you.
• At the visit, write down the name of a new diagnosis and any new medicines, treatments, or tests. Also write down any new instructions your doctor gives you.
• Know why a new medicine or treatment is prescribed, and how it will help you. Also know what the side effects are.
• Ask if your condition can be treated in other ways.
• Know why a test or procedure is recommended and what the results could mean.
• Know what to expect if you don't take the medicine or have the test or procedure.
• If you have a follow-up appointment, write down the date, time, and purpose for that visit.