Choroid plexus tumors

What are choroid plexus tumors?

Choroid plexus tumors are rare growths of cells that form in the choroid plexus, a vascular structure inside the brain's ventricles – a network of chambers filled with cerebrospinal fluid. Choroid plexus tumors are divided into two types – papillomas and carcinomas. Together, choroid plexus tumors account for fewer than 1 percent of pediatric brain tumors.

Most choroid plexus tumors are benign. The prognosis, or likely outcome of the disease and chance of recovery, for a choroid plexus tumor depends on many factors, including:

• Tumor grade
• Tumor location
• Tumor type
• How much it has spread
• Genetics
• The patient's age
• The tumor that remains after surgery (if surgery was performed)

Choroid plexus tumors are grouped into three grades based on specific characteristics:

Grade 1. These are choroid plexus papilloma tumors. They are benign tumors that grow slowly.

Grade 2. These mid-grade tumors are an unusual form of choroid plexus papilloma. They are also benign but have a higher chance of growing back after being removed.

Grade 3. These are choroid plexus carcinoma tumors. They are fast-growing malignant tumors that are more likely to spread to other parts of the brain.

Symptoms of choroid plexus tumors

Because these tumors grow in the brain's ventricular system, they often block the flow of cerebrospinal fluid, causing a buildup of fluid and pressure called hydrocephalus. Symptoms of hydrocephalus usually include headaches, vomiting and occasionally weakness of the arms or legs.

Diagnosis of choroid plexus tumors

Choroid plexus tumors are usually diagnosed based on their appearance and location. These tumors are located in the ventricles of the brain and have a cauliflower-like appearance which often helps distinguish them from other types of brain tumors. The diagnosis is done using images from an MRI scan of the child's brain.

Choroid plexus carcinomas can, however, resemble other types of malignant tumors, and the diagnosis is often only confirmed after a pathologist has examined a sample of tissue taken during surgery.

Treatment of choroid plexus tumors

A choroid plexus tumor is a serious condition that needs to be treated by a team that includes neurosurgeons, neuro-oncologists and radiation oncologists. As with most tumors, we treat this condition with a combination of surgery, radiation or chemotherapy.

Surgery for choroid plexus tumors

Surgical removal of the tumor is the most effective treatment for choroid plexus tumors. Surgery often cures choroid plexus papillomas, and patients with choroid plexus carcinomas have improved outcomes when the tumors can be completely removed.

Choroid plexus tumors often contain many blood vessels. To make surgery safer, in some cases we first do a minimally invasive procedure called embolization that blocks blood supply to the tumor.

Chemotherapy for choroid plexus tumors

Aggressive chemotherapy, with or without high-dose chemotherapy with stem cell rescue, is often used in patients with choroid plexus carcinomas. Stem cell rescue is used to replace blood-forming stem cells that were destroyed by high doses of anticancer drugs. Several small studies suggest that aggressive chemotherapy improves outcomes, especially in patients with tumors that could not be completely removed with surgery.

 

Radiation therapy for choroid plexus tumors

Radiation therapy can be an effective treatment for choroid plexus carcinomas. However, high doses of radiation can be toxic to the developing brains of young children. Radiation therapy is, therefore, often reserved for patients whose tumors have recurred after initial treatment, or for those with metastatic disease who do not respond to chemotherapy.