Choroid plexus carcinoma poses a serious challenge in the world of brain cancers. It not only poses difficulty in diagnosis, because of non-specific symptoms, but it primarily affects children who cannot express themselves. With the use of MRI however, we can easily discover tumours, giving hints about the severity and location of the tumour, along with providing guidance to surgeons for treatment. Choroid plexus carcinoma is challenging to treat due to its presence in a critical brain region, and there are alternative therapies available for treatment after surgery.

This article explores the process of diagnosing choroid plexus carcinoma, along with the possible treatment options currently available. 

What is choroid plexus carcinoma?

Choroid Plexus Carcinoma (CPC) is a rare but aggressive form of brain tumour. It specifically refers to tumours of the choroid plexus epithelium, a structure within the ventricular system of the brain which is responsible for producing cerebrospinal fluid (CSF). 

They account for 0.5% of all brain tumours in both adults and children.¹ However, they are more common in children as around 80% of CPCs arise in children,² with 10%-20% of those cases being diagnosed within the first year of life.¹

Choroid plexus tumours are classified into three different grades based on their severity and characteristics:

• Grade 1 choroid plexus tumours are also known as choroid plexus papillomas. The tumours are benign, meaning they are non-cancerous, and the tumour cells grow slowly
• Grade 2 atypical choroid plexus tumours are classified as mid-grade benign tumours
  • They differ from grade 1 because they have a higher possibility of coming back in the same location after being surgically removed
• Grade 3 is known as a choroid plexus carcinoma, which is the malignant grade of choroid plexus tumours, meaning they are cancerous
  • They are fast-growing tumours that are likely to spread to other areas of the central nervous system (CNS), with one-fifth of cases having spread to the rest of the CNS by the time of discovery

Diagnosis of choroid plexus carcinoma

Symptoms and signs

Although the symptoms of CPC may resemble other common illnesses or conditions, it is important to consult with a medical professional, particularly for the diagnosis of a child. Symptoms of CPC may include:

• Headaches- particularly in the morning
• Confusion
• Seizures
• Nausea or vomiting
• Lethargy, weakness, or a loss of sensation in the arms or legs
• Personality changes
• Problems with speech, memory, or vision

Symptoms specific to children include:

• Irritability - often in children as they can’t express where they have pain
• Increase in head size (infants)
• Problems feeding or walking
• Enlarged fontanelles- which are the soft spots between the skull bones of infants

Following the reporting of these symptoms, a clinical evaluation is the next step in the diagnosis of CPC. This often includes a complete medical history followed by the physical exam, which can include neurological function tests for reflexes, coordination, alertness, muscle strength, and eye and mouth movement.

Genetic susceptibility

Although one may want to know the cause of CPCs, these brain cancers most commonly appear with no cause. However, a medical condition known as Li Fraumeni Syndrome is strongly associated with CPC. Li Fraumeni is a cancer predisposition syndrome, associated with a high risk of various cancers, from childhood all the way to adulthood.³ It is a germline mutation of the tumour suppressor gene, TP53, meaning it is a mutation in sperm or egg cells and can be passed on from parents to offspring.³

Previous research has shown a correlation between CPC and Li Fraumeni and there was a 36% association recorded between the two conditions.⁴ This research highlights the importance of genetic testing, as it can significantly aid in the diagnosis of cancers, especially in children who cannot express themselves and their symptoms. It should be noted however that Li Fraumeni is quite rare as well. Brain imaging

As symptoms and physical exams alone cannot determine the existence of brain tumours, magnetic resonance imaging, more commonly known as MRI, is used as a brain imaging technique to get a clearer image of what is going on. An MRI can provide a high-contrast image of soft tissues like the brain, showing any abnormalities or damage to the brain, and CPC appears very clearly on MRI scans with clear borders.⁵

With MRI, it may be quite difficult to differentiate between the grade 1 and grade 2 choroid plexus tumours and the grade 3 carcinoma. It may also be difficult to differentiate between different types of brain cancer.⁶ However, MRIs can guide us to whether the tumour found is near the choroid plexus or within the ventricular system, or if it has spread to other parts of the brain, hinting at a malignant tumour.⁷

An MRI is incredibly helpful not only as a firm and reliable method of diagnosing tumours such as CPC, but it is also useful for future surgeries, as it allows surgeons to adapt their method to the size and location of the tumour.⁷ This is particularly important with CPCs as they are known to be more haemorrhagic.

Therefore, MRIs are useful in initial diagnosis and pre-surgical planning, but also incredibly useful for checking patients after treatment, as choroid plexus tumours can come back.

Treatment

Surgery

The primary treatment of all choroid plexus tumours is surgery. With surgery, you also obtain tissue for analysis to be able to determine the specific tissue type and grade of the CPC, which could not be done through MRIs.

The removal of tumours is known as resection, and resection has been seen to greatly improve outcomes of people with CPCs and fully cure grade 1 choroid plexus tumours.⁶ A complete resection with choroid plexus tumours is quite challenging; however, as the brain is not only incredibly delicate but choroid plexus tumours are very vascular. This poses a high risk of bleeding during surgery and a huge risk for survival. Even with these challenges; however, quite a few of the surgeries are successful with many of the tumours being fully removed with no major long-term complications after surgery.¹ This being said, there have been cases of mortality and serious complications, but this isn’t guaranteed. 

Although the full removal and treatment of choroid plexus tumours is possible, this may not necessarily apply to CPCs. With CPCs, the spread of the cancerous tumours to other parts of the CNS was recorded in all the CPC patients in a study, and they were not fully treated.¹ Since the removal of tumours for grade 3 choroid plexus tumours is particularly difficult, it is recommended that patients either go through a second surgery or post-surgery therapies such as chemotherapy or radiation therapy.

Post-surgery therapies

Chemotherapy and radiation therapy are two well-known methods for combating cancer, which can also be applied to the treatment of CPCs. Due to the complications of surgically removing a tumour in a sensitive area, which has already spread to other areas of the brain, these measures ensure the patient is cancer-free.

Chemotherapy

Chemotherapy is the use of powerful medicine to prevent the growth of cancer cells. It works by stopping cancer cells from reproducing, and by slowing down the cancer’s growth, it is prevented from spreading around the body. It can cure cancer completely; however, the medication targets all fast-growing cells, not just cancer cells. This is the cause of the side effects of chemotherapy because it does kill cancer cells but it also kills healthy cells such as skin cells, blood cells, and the cells in your stomach.

Radiation therapy

Radiation therapy, also known as radiotherapy, is a cancer therapy method which involves powerful radiation beams to kill cancer cells. It uses high doses of radiation to shrink tumours and kill cancer cells by damaging their DNA. When the DNA of a cell is damaged it dies, so the cancer cells which had their DNA damaged beyond repair will slowly stop dividing, and then die. These dead cells are then broken down and removed by the body.

There are two types of radiotherapy that are normally used, external beam radiation therapy and internal radiation therapy. With external radiation, a machine aims the radiation towards your cancer, meaning it is a local treatment. With internal radiation, the source of radiation can be put inside you either as a liquid or solid. Liquid internal radiation is the only non-specific treatment, as solid internal radiation can be placed at the tumour site and act as a local treatment for cancerous growth.

Summary

CPC is a challenging medical condition that primarily affects children. This poses challenges in diagnosis because of the vague symptoms and its similarity to other brain tumours on MRI scans. Surgical treatment of this challenging condition is the primary solution; however surgical intervention of such soft tissue poses many risks. Although treatment of grade 1 and grade 2 choroid plexus tumours has shown to be successful in fully removing the benign growth, it doesn’t have the same success with CPC because of its tendency to spread to other parts of the CNS. With CPC, post-surgery therapies need to be used such as chemotherapy or radiotherapy, or potentially a second surgery.