Choroid plexus tumors

Overview

Choroid plexus tumors are a rare proliferation of cells arising from the choroid plexus, a vascular structure inside the ventricles of the brain, interconnected cavities filled with cerebrospinal fluid. Choroid plexus tumors are divided into two types — papillomas and carcinomas. Together, these lesions constitute fewer than 1 percent of childhood brain tumors.

Choroid plexus papillomas account for 60 to 70 percent of choroid plexus tumors. They are benign and do not spread within the ventricular system or brain. They usually occur in young children, either infants or toddlers.

Choroid plexus carcinomas are malignant tumors that have the potential to spread throughout the ventricular system and brain. They are more common in patients with Li-Fraumani Tumor predisposition syndrome, which results from inherited mutation of the TP53 gene. Children with choroid plexus carcinomas should be screened for this syndrome, and parents may benefit from genetic counseling.

Signs & symptoms

Because these lesions grow within the ventricular system, they often obstruct the flow of cerebrospinal fluid and causing a buildup of this fluid, a condition called hydrocephalus. Symptoms of hydrocephalus usually include headaches, vomiting and occasionally weakness of the arms or legs.

Diagnosis

Choroid plexus tumors are usually diagnosed based on their appearance and location, using images from an MRI scan of the brain. These tumors are located in the ventricles of the brain and they have a typical appearance that often helps distinguish them from other types of brain tumors.

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

Treatment

A choroid plexus tumor is a serious condition that needs to be treated by a multi-disciplinary team consisting of neurosurgeons, neuro-oncologists and radiation oncologists. Even with appropriate treatment, a fraction of patients die from this disease.

As with most tumors, our treatments are limited to three modalities: surgery, radiation and chemotherapy.

Surgery

Surgical removal 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. In some circumstances, surgery can be made safer if the blood supply to the tumor is closed, using a technique called embolization, before the actual surgery.

Chemotherapy

Aggressive chemotherapy, with or without high dose chemotherapy with stem cell rescue, is often used in patients with choroid plexus carcinomas. Several small studies appear to show this improves outcomes, especially in patients who were unable to have the tumor completely removed with surgery.

Radiation

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