Choroid Plexus Tumors
Choroid plexus tumors arise in the brain structures that produce cerebrospinal fluid (CSF). Common surgical treatments include craniotomy, endoscopic craniotomy, and shunt placement.
Although these tumors can appear in any of the brain’s ventricles, they tend to develop in the fourth ventricle among adults and in lateral ventricles among children. In any of these locations, tumors arising along the choroid plexus can block the circulation of CSF and even cause the overproduction of CSF, leading to hydrocephalus and increased intracranial pressure.
There are two types of choroid plexus tumors, and they can be assigned numerical grades on the basis of how abnormal their tumor cells are. The more abnormal the cells, the higher the grade.
- Choroid plexus papillomas represent about 80 to 90 percent of choroid plexus tumors and are usually benign, slow-growing Grade I or II tumors.
- Choroid plexus carcinomas, accounting for the remaining 10 to 20 percent of choroid plexus tumors, are malignant and grow more quickly than choroid plexus papillomas. These are Grade III and can invade surrounding brain tissue.
Both types of tumors can compress brain tissue as they expand and grow. Circulating CSF may pick up tumor cells, allowing them to metastasize to other areas in the brain or spine—particularly in the case of choroid plexus carcinomas.
The most common symptoms of choroid plexus tumors are hydrocephalus and signs of increased intracranial pressure, which include headache, nausea, vomiting, and lethargy. A headache typical of excessive intracranial pressure is most severe in the morning upon waking and may abate as the day progresses.
Papilledema and visual disturbances, such as diplopia, may also occur.
Infants and very young children with hydrocephalus may have macrocephaly or enlarged fontanels.
Typically, a neurological examination is performed to assess symptoms.
The key component to diagnosis, as is the case for nearly all brain tumors, is imaging. Magnetic resonance imaging (MRI) scans or computed tomography (CT) scans can be used, although MRI tends to be used more often. Most often the study will be done with contrast enhancement.
What causes choroid plexus tumors is currently unknown.
Most of these tumors are sporadic, but some may be associated with rare genetic syndromes. Choroid plexus papillomas are associated with several genetic conditions, such as von Hippel-Lindau syndrome, Li-Fraumeni syndrome, Aicardi syndrome, Down syndrome, and neurofibromatosis type 2. Choroid plexus carcinomas are associated with the genetic conditions Li-Fraumeni syndrome and rhabdoid predisposition syndrome.
Choroid plexus tumors are very rare among adults, making up only about 1 percent of brain tumors. They are more common among children, accounting for about 10 to 20 percent of tumors in children younger than age 1, and 2 to 4 percent of tumors among children younger than 15. Most often, these tumors arise in the mid-teenage years.
Choroid plexus carcinomas tend primarily to be found among children and occur equally among males and females. Males have nearly a three times greater risk than females of developing choroid plexus papillomas.
At Columbia, our neurosurgeons use the latest surgical techniques to treat choroid plexus tumors, resulting in optimal outcomes for patients. Prognosis largely depends on how much tumor is removed.
For nearly all choroid plexus tumors, brain tumor surgery is the primary treatment, and it can result in a cure if complete resection is achieved. Tumor resection can be done a few different ways, and our neurosurgeons choose the approach most suitable for a particular patient’s tumor. The traditional approach is craniotomy, an open procedure during which the neurosurgeon temporarily removes a piece of skull bone to obtain access to the brain.
Hydrocephalus usually resolves after tumor resection, but if it doesn’t, a shunt can be inserted to divert the CSF.
Because of their tendency to infiltrate surrounding tissue, choroid plexus carcinomas may not be amenable to total removal. So as not to risk harming important, healthy structures, neurosurgeons perform subtotal resection in such situations. Adjuvant treatment with radiotherapy, chemotherapy or both may be needed to treat the residual tumor and prevent tumor recurrence.
If tumor recurrence occurs, resection, radiotherapy, chemotherapy, or a combination of these approaches may be recommended. Stereotactic radiosurgery may be administered—a noninvasive process in which high doses of radiation are focused at the tumor cells, leaving the adjacent brain tissue unaffected.
The protocol is somewhat different for very young patients: Radiotherapy is avoided in children under age 3 because of potential negative effects on the child’s developing brain; chemotherapy can be used instead.