Choroid Plexus Tumor

What is Choroid Plexus Tumor?

Choroid plexus tumors (CPTs) are rare tumors that begin in the ventricles of the brain. The ventricles are spaces in the brain that are filled with cerebrospinal fluid (CSF). Choroid plexus tumors may be benign or malignant. CPTs most often occur in infants, but they can develop at any age.

Choroid plexus tumors account for 3% of childhood brain tumors, but they represent 10-20% of brain tumors in infants under 1 year of age. Approximately 75-80 new cases of CPT are diagnosed annually in the United States in children and young adults under 21 years of age.

There are 2 main types of choroid plexus tumor:

• Choroid plexus papilloma (CPP) is the most common type of choroid plexus tumor. About 80% of choroid plexus tumors are CPPs. These are noncancerous and grow slowly. These tumors are most often seen in the lateral ventricle in children. They rarely spread to other parts of the CNS.
• Choroid plexus carcinoma (CPC) is a cancerous form of choroid plexus tumor. It grows faster and is more likely to spread through the cerebrospinal fluid to other CNS tissues. About 10-20% of choroid plexus tumors are CPC.

The main treatment for choroid plexus tumor is surgery. Additional treatments including chemotherapy and radiation therapy may be used depending on the type of tumor and the extent of disease after surgery.

Signs and Symptoms of Choroid Plexus Tumor

Symptoms of CPT vary based on the child’s age and tumor location. As the tumor grows, it blocks the normal flow of cerebrospinal fluid. This causes a build up of fluid within the brain known as hyrodcephalus. The fluid causes the ventricles to widen and increases pressure on the brain (intracranial pressure). Many of the symptoms of choroid plexus tumor are due to the increased pressure against brain tissue.

Choroid plexus tumor symptoms may include:

• Headache, often worse in the morning and/or improves after vomiting
• Nausea and vomiting
• Changes in activity levels, lethargy
• Difficulty walking 
• Problems feeding
• Change in behavior or irritability
• Increased head size in infants
• Increase of fullness of the fontanel (“soft spot” at the top of the skull)

Diagnosis of Choroid Plexus Tumor

Doctors test for choroid plexus tumors in several ways. These tests include:

• A health history and physical exam helps doctors learn about symptoms, general health, past illness, risk factors, and developmental milestones.
  • Most choroid plexus carcinomas occur in infants and young children less than 5 years of age. There is an increased risk of developing choroid plexus carcinoma with Li-Fraumeni syndrome, a cancer predisposition syndrome.
    
• A neurological exam examines the function of the brain, spinal cord, and nerves. These tests measure different aspects of functioning including memory, vision, hearing, muscle strength, balance, coordination, and reflexes.
• Imaging tests such as magnetic resonance imaging (MRI) and computerized tomography (CT) create detailed pictures of the ventricles, brain, and spinal cord. Doctors can see the size and location of the tumor and better understand what areas of the brain might be affected.  
• A lumbar puncture may be performed to look for cancer cells in the cerebrospinal fluid.
  
• A biopsy is performed to diagnose CPT. In a biopsy, a small sample of the tumor is removed during surgery using a needle. A pathologist looks at the tissue sample under a microscope to identify the specific type of tumor.

Grading and Staging of Choroid Plexus Tumor

Depending on the histology and type of tumor, the choroid plexus tumor may be benign or malignant. CPTs are diagnosed as choroid plexus papilloma (CPP), noncancerous, or choroid plexus carcinoma (CPC), cancerous.

Tumors can be grouped by how they look under the microscope. The more abnormal cells look, the higher the grade. Choroid plexus papillomas are usually Grade I tumors and are generally benign. Choroid plexus carcinomas are typically grade III tumors. They are more aggressive in nature and grow very rapidly.

Staging of choroid plexus tumor involves obtaining an MRI of the spine and brain to look for the extent of spread of disease and a lumbar puncture to look for cancer cells in the CSF.

Prognosis for Choroid Plexus Tumor

Chance of cure is very good if surgery can completely remove the tumor. With successful surgery for choroid plexus papilloma (CPP), survival rates approach 100%. Choroid plexus carcinoma (CPC) is more aggressive, but chance of cure is approximately 50-70%.

Factors that influence prognosis include:

• Histology. Children with CPP have a better prognosis compared to children with CPC.
• Age of the child. Children under 4 years old have a poorer prognosis.
• Whether the cancer has spread to other areas of the brain and spinal cord. 
• How much of the tumor remains after surgery. Complete resection of the tumor improves chance of survival.
• If there are certain genetic syndromes (e.g., Li-Fraumeni or germline TP53 mutation). 
• The use of radiation to treat the tumor.
• The presence of TP53 mutations in the tumor. The chance of survival decreases significantly with the presence of TP53 gene mutations in the tumor. Children with 2 copies of the mutated gene in their tumor have an extremely poor prognosis.

Treatment of Choroid Plexus Tumor

Treatment depends on several factors including the size and location of the tumor, the child’s age, and the tumor types (CPP vs CPC). Treatment for choroid plexus tumors may include surgery, chemotherapy, and radiation. Choroid plexus papillomas and atypical choroid plexuses tumors are primarily managed by surgery when possible. Choroid plexus carcinoma is a more aggressive cancer, and most patients will receive multiple types of treatments.

Life after Choroid Plexus Tumor

Children who are long term survivors of CPT need close and prolonged monitoring for late effects of the treatment. Children with a germline TP53 mutation or Li-Fraumeni syndrome need referral to genetic counseling and surveillance for other cancers associated with this syndrome.

More: Life After Brain Tumors