Table of Contents
Introduction:
Choroid plexus tumors are rare tumors that develop inside the choroid plexus of the brain's ventricles. The choroid plexus lines the brain's ventricles, and its main function is to produce cerebrospinal fluid (CSF). It also plays an important role in maintaining the homeostasis of the CNS. The choroid plexus also acts as a protective barrier, preventing harmful substances from entering the brain and aiding in removing waste products from the CSF. Choroid plexus tumors pose unique diagnostic and management challenges due to their location and the potential for rapid growth.
What Is a Choroid Plexus Tumor?
Choroid plexus tumors are uncommon central nervous system (CNS) tumors, accounting for only a small percentage of all central nervous system tumors. However, their rarity does not diminish their clinical significance. They are most commonly found in children, about 60-70 % of cases occurring in pediatric patients.
However, they also occur in adults at any age. Benign tumors typically occur in pediatric patients, while malignant ones are more common in adults. Pediatric patients may present with altered mental status or increasing head circumferences; in adults, they present with increased intracranial tension signs.
Radiologic imaging plays a vital role in their detection and characterization, as it shows intraventricular enhancing masses. Surgery is an effective treatment for these tumors, providing a good prognosis in benign tumors. Improvements in surgical techniques have improved survival.
What Are the Types of Choroid Plexus Tumors?
Choroid plexus tumors can be classified into two types based on their histopathological characteristics:
Choroid Plexus Papilloma (CPP)
Choroid plexus papillomas are benign tumors and are more common than their malignant form. They represent about 80 to 90 percent of choroid plexus tumors. They predominantly occur in pediatric groups and are generally associated with a more favorable prognosis. These tumors are slow-growing tumors and are usually confined to the ventricular system. Choroid plexus papillomas present with finger-like projections (papillae) and are characterized by well-differentiated epithelial cells with a low mitotic rate. These tumors grow slowly and are usually confined to the ventricular system.
Choroid Plexus Carcinoma (CPC)
Choroid plexus carcinomas are malignant tumors that are more prevalent in adults. However, it also occurs in children. About 10 to 20 percent of choroid plexus tumors are malignant. These tumors have aggressive growth and are linked with a higher risk of metastasis and recurrence. Histological features show malignancy, including nuclear atypia, high mitotic activity, and invasion into surrounding brain tissue.
Benign and malignant tumors can expand and grow by compressing the brain tissues. The CSF may pick up tumor cells, leading to metastasizing to other areas in the brain or spine, mainly in the choroid plexus carcinomas.
What Are the Clinical Features of Choroid Plexus Tumors?
The clinical features of choroid plexus tumors may differ depending on various factors, including the patient's age, tumor size, location, and associated hydrocephalus (buildup of cerebrospinal fluid in the ventricles). However, the most common symptom of choroid plexus tumors is headaches, caused by increased intracranial pressure in the brain caused by the tumor. This tumor can alter CSF fluid and cause other symptoms due to its mass.
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Nausea.
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Vomiting.
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Irritability.
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Altered mental status.
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Headaches.
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Abnormal eye movements.
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Blurred or double vision.
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Strong desire to sleep.
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Focal neurological deficits.
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Trouble with walking.
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Increase in the size of the head.
How Are Choroid Plexus Tumors Diagnosed?
Diagnosis for choroid plexus carcinoma is done by performing a neurological examination. Also, imaging techniques are the key component in diagnosing choroid plexus tumors. Imaging techniques help distinguish choroid plexus carcinoma from other intraventricular masses and guide proper treatment decisions. Computed tomography (CT) scans or magnetic resonance imaging (MRI) scans are commonly used, although MRI tends to be used more often. The tests and procedures used for choroid plexus carcinoma diagnosis include:
1) Neurological Exam - The patient's vision, hearing, coordination, balance, and reflexes are tested during this exam. This test helps to show which part of the brain may be affected by the tumor.
2) Imaging Tests
Computed Tomography (CT)
CT scan is the first imaging modality used for checking intracranial masses due to their widespread availability and speed. Choroid plexus tumors typically appear as well-defined, intraventricular masses in CT scans.
Other features include:
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Choroid plexus tumors are generally of the same density as brain tissue or slightly hyperdense, making them difficult to distinguish from the surrounding structures.
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These tumors may exhibit amorphous or punctate calcifications.
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Choroid plexus tumors can cause obstructive hydrocephalus and local mass effects, leading to ventricular dilation.
Magnetic Resonance Imaging (MRI)
MRI provides superior soft tissue contrast and is considered the gold standard for diagnosing choroid plexus tumors.
Magnetic Resonance Spectroscopy (MRS)
Magnetic resonance spectroscopy provides additional information about the chemical composition of the tumor. Generally, choline levels will be elevated in choroid plexus tumors, which can be a helpful diagnostic indicator.
What Is the Treatment for Choroid Plexus Tumors?
The treatment of choroid plexus tumors depends on multiple factors, including the patient's age, size and location, tumor type, and overall health. The treatment options include surgical resection, chemotherapy, radiation therapy, and ongoing monitoring.
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Surgery - The surgery aims to remove cancer completely. However, due to the presence of delicate and important structures nearby, surgeons sometimes cannot completely remove cancer cells in all cases. So, adjuvant therapies are required after surgery.
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Chemotherapy - In this therapy, the cancer cells are destroyed using drugs. It may be used in combination with surgery and radiation therapy. Chemotherapy regimens may include drugs like Etoposide, Cisplatin, and Cyclophosphamide. The choice of chemotherapy drug and duration of treatment depend on the tumor type and the patient's response to therapy.
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Radiation therapy - In this therapy, powerful energy beams kill tumor cells. The energy for radiation therapy can come from X-rays, protons, and other sources. Radiation therapy is indicated when complete resection is not possible or when there is tumor recurrence.
Conclusion
Choroid plexus tumors are rare tumors that affect the brain's choroid plexus. It can affect both children and adults. However, it is more prevalent in pediatric patients. The symptoms vary depending on the patient's age, the type of tumor, and its site of occurrence. Surgery is the main treatment option for choroid plexus tumors; it can be combined with chemotherapy and radiation therapy. Also, research into targeted therapies is ongoing, which can provide more beneficial results shortly.
