26th June 2023

Brain and Spinal Tumours

Features of Brain and Spinal Tumours

Common symptomatology of brain tumours 

The symptoms of brain tumours are usually progressive, and you may meet a patient at the start of their journey or when their tumour has progressed to an advanced stage. Therefore, it is important to understand the red flag symptoms that may be associated with a potential brain tumour diagnosis and have a low threshold for investigation as the symptomatology may be subtle.

As with all pathologies involving a high metabolic activity, lethargy and weight loss can be a common feature due to the increased energy expenditure by the growing lesion. Social withdrawal, poor sleep and behavioural changes can be some of the subtle changes reported by the patient or their loved ones.

Raised intracranial pressure (ICP) associated with a space-occupying lesion in the brain can cause a variety of symptoms. Headaches are a commonly reported symptom; classically, the headache is worse in positions of increased ICP, such as when straining, lying down, or in the early morning. Nausea and vomiting are other common symptoms caused by raised ICP. Papilloedema may be seen on fundoscopy (see image below) and is another sign of increased ICP. This can be experienced as blurred or double vision; a bulged optic disc, blurring of disc margins and microhaemorrhages may be seen on fundoscopy.

Depending on the location of the lesion, focal neurological deficits in an upper motor neuron pattern may be seen, including numbness, weakness, spasticity, and hyperreflexia. Vertigo or gait disturbance may occur due to pressure on, or involvement of, the cerebellum. Visual loss can be experienced if the optic nerve is compressed by the tumour, or due to surrounding oedema.

Seizures are experienced in up to 80% of patients with brain tumours due to disruption of the normal impulses of the neurons in and around the tumour, and the compression of surrounding structures.

Retinal image showing evidence of papilloedema

Image Source: Wikimedia Commons (2011). Papilledema, Licensed under a creative commons licence. Available for free at: https://commons.wikimedia.org/wiki/File:Papilledema.jpg (Accessed on: 30 January 2023).

Localising the lesion 

Symptoms can vary depending on the location of the brain lesion; commonly in MRCP, clues are given within the patient history to help to localise the lesion. Understanding the different functions of the lobes of the brain can help to identify the area likely affected prior to imaging. This is covered in more detail in the ‘Basic Neuroanatomy’ section.

Frontal lobe

The frontal lobe controls personality, speech fluency (via Broca’s area) and the coordination of movement (via the primary motor cortex). A lesion here may therefore cause motor weakness, changes in personality and problem solving, loss of smell or speech changes.

Parietal lobe

The parietal lobe is involved with coordination of sensory and spatial stimuli. It is the part of the brain that allows us to recognise faces and stores the memory for reading and writing. A lesion here may cause difficulty with spatial awareness, weakness or sensory changes, or astereognosis (inability to recognise objects by touch).

Temporal lobe

The temporal lobe is involved in speech comprehension (Wernicke’s area) and processing of sounds and memories. A tumour in this region can cause short term memory loss or language and speech difficulties.

Occipital lobe

The occipital lobe is involved in visual perception. A tumour located in this area may cause changes in vision, such as size, shape, visual deficits, and colour identification.

Cerebellum

The cerebellum controls balance, coordination, and posture. A tumour in this area may cause dizziness, ataxia, nystagmus, and nausea.

Brain stem

The brain stem controls important body functions such as breathing, swallowing, sneezing, and coughing.

Lobes of the brain.

Image Source: Wikimedia Commons (2016). 1306 Lobes of Cerebral CortexN, Licensed under a creative commons licence. Available for free at: https://commons.wikimedia.org/wiki/File:1306_Lobes_of_Cerebral_CortexN.jpg (Accessed on: 30 January 2023).

Common symptomatology of spinal tumours 

Spinal tumours (both primary and secondary) can give rise to back pain, which may be associated with tenderness to palpation at a specific vertebral level. Numbness and neuropathic pain can arise from compression of nerves by the tumour or surrounding oedema. Compression below the level of the termination of the spinal cord in adults at L1-L2 may result in cauda equina syndrome, which may present with bladder and bowel dysfunction, saddle anaesthesia, and sensory or motor changes in the lower limbs. This is an oncological emergency due to the risk of permanent neurological deficit. As with all cancers, symptoms such as weight loss, fatigue and night sweats may also be reported.

There are some background diagnoses, albeit rare, that can predispose to spinal tumours. Neurofibromatosis type 1 (NF1) is an autosomal dominant condition associated with the development of nerve sheath tumours, which are mostly benign neurofibromas, however, there is a small risk of malignant transformation. Other signs of NF1 include axillary freckling, café-au-lait spots, Lisch nodules of the iris, and optic gliomas. Neurofibromatosis type 2 (NF2) is associated with benign vestibular schwannomas, meningiomas and ependymomas. NF2 can be associated with sensorineural hearing loss due to the development of vestibular schwannomas (acoustic neuromas) around cranial nerve VIII. NF2 is more associated with symptomatic spinal tumours than NF1.

Von Hippel-Lindau syndrome (VHL) is another autosomal dominant hereditary condition associated with the development of tumours and cysts in multiple parts of the body. Haemangioblastomas are one of the types of tumours associated with VHL; these are benign tumours arising from the blood vessels of the brain, spinal canal, and retinas. VHL is also associated with the development of some cancerous tumours, especially of the kidneys, phaeochromocytomas and endolymphatic sac tumours.

Brain Tumours

Classification of brain tumours

There are 3 common different ways to subdivide brain tumours:

• Intrinsic vs Extrinsic
  • ‘Intrinsic’ tumours are classified as tumours arising from within the brain. Those that grow from structures around the brain, such as cranial nerves, spinal nerves and dura, are classified as ‘extrinsic’ tumours.
• Benign vs Malignant
  • Slow-growing tumours such as schwannomas and meningiomas tend to be benign, however, tumours such as gliomas are usually malignant.
• Primary vs Secondary: Primary tumours are those that originate from the cranial tissues, whilst secondary tumours are metastatic and have spread from elsewhere in the body. A full body CT can help to establish whether there are any other tumours within the body. Metastatic (secondary) brain tumours are three times more common than primary brain tumours. A biopsy can determine the tissue of the tumour. Lung, breast, bowel, skin, and kidney tumours are the most common sites that metastasise to the brain.

Types of brain tumours

Glioma

Gliomas originate from glial cells. Glial cells are non-neuronal cells that have many functions involving neuronal pruning, producing myelin and modulating neuronal growth. Glial cells include astrocytes, oligodendrocytes, and ependymal cells. Tumours of these cells can give rise to astrocytomas or glioblastomas, oligodendrogliomas, or ependymomas, respectively. Astrocytomas are by far the most common type of glioma in both adults and children; they can be low grade (Grade 1 and 2 – slow-growing) or high grade (Grade 3 and 4 – fast-growing). Grade 4 astrocytomas are more commonly called glioblastoma multiforme (GBM). The imaging shows a ring enhancing lesion with central necrosis, typical of GBM. Prognosis for GBM is poor; the average survival time is just 12-18 months.

Glioma on MRI brain.

Image Source: Wikimedia Commons (2009). Glioma, Licensed under a creative commons licence. Available for free at: https://commons.wikimedia.org/wiki/File:Glioma.gif (Accessed on: 30 January 2023).

Meningioma

Meningiomas are slow-growing tumours arising from the lining (meninges) that encapsulates the brain and spinal cord. This is a benign tumour that rarely metastasises and is usually monitored with surgical resection if impeding on neurological structures. Meningiomas account for 25% of all brain tumours.

Meningioma on CT.

Image Source: Wikimedia Commons (2007). Contrast enhanced meningioma, Licensed under a creative commons licence. Available for free at: https://commons.wikimedia.org/wiki/File:Contrast_enhanced_meningioma.jpg (Accessed on: 11 January 2023).

Vestibular Schwannoma

These are slow-growing tumours that form along the vestibulocochlear nerve (CNVIII). These are benign tumours of vestibulocochlear Schwann cells. Patients may present with tinnitus, unilateral sensorineural hearing loss, vestibular dysfunction causing dizziness and rarely ipsilateral disturbances of facial pain (CNV) and facial weakness (CNVII). These tumours can be managed conservatively by MRI monitoring; however, if compressing adjacent structures, surgical resection and stereotactic radiosurgery are the main management options.

Vestibular Schwannoma on MRI brain

Image Source: Wikimedia Commons (2008). Vestibular-schwannoma-003, Licensed under a creative commons licence. Available for free at: https://commons.wikimedia.org/wiki/File:Vestibular-schwannoma-003.jpg (Accessed on: 30 January 2023).

Medulloblastoma

Medulloblastomas are high-grade solid tumours located in the cerebellum, usually in children. Metastases can occur within the CSF to other parts of the brain and spinal cord; therefore, a full spine MRI is important as metastases are present in 1/3rd of children at presentation. Treatment is tumour-specific, often involving radiation, chemotherapy, and surgery.

Medulloblastoma on MRI brain

Image Source: Wikimedia Commons (2005). CT brain scan of child with medulloblastoma and resulting hydrocephalus, Licensed under a creative commons licence. Available for free at: https://commons.wikimedia.org/wiki/File:CT_brain_scan_of_child_with_medulloblastoma_and_resulting_hydrocephalus.jpg (Accessed on: 30 January 2023).

Craniopharyngioma

Arising from the pituitary stalk, these benign tumours can affect the production of hormones from the hypothalamus or pituitary glands and may even present as pituitary insufficiency. As the tumour site is situated above the optic chiasm, patients may develop a bitemporal inferior quadrantinopia, which may progress to a bitemporal hemianopia as the tumour grows. Clinical features may include headache, visual changes, excessive urination and dehydration (due to diabetes insipidus), delayed puberty in children or sexual dysfunction in adults, symptoms of hypothyroidism such as weight gain, or symptoms of adrenal insufficiency.

Craniopharyngioma on MRI brain.

Image Source: Wikimedia Commons (2011). Craniopharyngioma-t1sagkm-006, Licensed under a creative commons licence. Available for free at: https://commons.wikimedia.org/wiki/File:Craniopharyngioma-t1sagkm-006.jpg (Accessed on: 11 January 2023).

Pituitary Adenoma

Pituitary adenomas are benign tumours arising from the pituitary gland (not to be confused with craniopharyngiomas which arise from the pituitary stalk, above the pituitary gland). They mostly affect the anterior lobe of the pituitary and are the most common cause of hypopituitarism. About half of pituitary adenomas do not secrete hormones and are called ‘non-functioning’ adenomas; however, they can still produce symptoms resulting from compression of surrounding structures, e.g. bitemporal hemianopia due to compression of the optic chiasm. Functioning adenomas secrete hormones and can result in symptoms of the following depending on the hormone secreted:

• Cushingoid symptoms
• Acromegaly
• Diabetes insipidus
• Hyperpituitarism
• Amenorrhoea/galactorrhoea/impotence

Pituitary adenoma on MRI brain

Image Source: Wikimedia Commons (2022). Coronal section of non-functioning pituitary adenoma, Licensed under a creative commons licence. Available for free at: https://commons.wikimedia.org/wiki/File:Coronal_section_of_non-functioning_pituitary_adenoma.jpg (Accessed on: 30 January 2023).

Haemangioblastoma

Haemangioblastomas are slow-growing benign tumours of the vascular system; they predominantly affect the cerebellum but can occasionally affect other sites, including the spinal cord and cerebrum. Von Hippel-Lindau syndrome is a rare inherited condition which is characterised by the formation of tumours and visceral cysts; haemangioblastomas are characteristic of Von Hippel-Lindau syndrome.

Cerebellar haemangioma on MRI.

Image Source: Wikimedia Commons (2007). Hippel Lindau, Licensed under a creative commons licence. Available for free at: https://commons.wikimedia.org/wiki/File:Hippel_Lindau.gif (Accessed on: 30 January 2023).

Immunosuppressed Patients 

Immunosuppressed states can significantly increase the risk of several brain lesions, outlined in this section. A brief understanding of these is important to be able to consider these diagnoses in clinical practice so that potential brain-sparing and life-saving treatments can be initiated early; they are also a common topic in MRCP questions.

Toxoplasmosis

Toxoplasmosis is caused by infection with the parasite Toxoplasma gondii, which is classically spread through infected meat that is inadequately cooked or through contact with oocysts from cat faeces.

Infection may cause symptoms such as headache, confusion, unsteady gait, seizures, and fevers in the immunosuppressed. Contrast CT features of cerebral toxoplasmosis include multiple ring-enhancing hypodense lesions in the basal ganglia and corticomedullary junction. Occasional mass effect and midline shift may be present due to the increasing size of the lesions. The treatment of acute toxoplasmosis in immunocompromised patients is with sulfadiazine and pyrimethamine. Prophylaxis with co-trimoxazole may be given to HIV-positive patients with low CD4+ counts.

Toxoplasmosis on MRI.

Image Source: Wikimedia Commons (2019). BrainToxoplasmosis MRI 4 11, Licensed under a creative commons licence. Available for free at: https://commons.wikimedia.org/wiki/File:BrainToxoplasmosis_MRI_4_11.png (Accessed on: 30 January 2023).

Primary CNS lymphoma

Primary CNS lymphoma (PCNSL) is a rare tumour confined to the central nervous system with no evidence of systemic spread. The risk of PCNSL is much higher in immunocompromised patients, particularly those with HIV/AIDS. PCNSL usually develops from B-cell lymphocytes; the most common subtype is diffuse large B-cell lymphoma and is associated with prior Epstein-Barr virus infection. The symptoms can include those of increased intracranial pressure (e.g. headache, vomiting), diplopia, behavioural changes, seizures, and focal neurological signs.

Radiological findings vary from well-circumscribed, solid, homogenous lesions in immunocompetent individuals, to peripheral enhancement with central necrosis of the lesion and vasogenic oedema in immunodeficiency-related CNS lymphomas. The majority of PCNSLs are solitary lesions, however, it can also present with multiple lesions.

Treatment options include steroids (to reduce the oedema surrounding the tumour), chemotherapy and radiotherapy. Neurosurgical resection may be considered for low grade tumours.

Primary CNS lymphoma on MRI brain

Image Source: Wikimedia Commons (2007). Tumor PrimaryCNSLymphoma T1Axial, Licensed under a creative commons licence. Available for free at: https://commons.wikimedia.org/wiki/File:Tumor_PrimaryCNSLymphoma_T1Axial.JPG (Accessed on: 30 January 2023).

Progressive multifocal leukoencephalopathy

Progressive multifocal leukoencephalopathy (PML) is a manifestation of infection with the JC virus in immunocompromised individuals. It causes progressive, widespread demyelination due to JC virus infection of oligodendrocytes within the brain. The symptoms are slow and insidious, including behavioural changes, speech, motor, and visual impairment. It almost exclusively affects those who are severely immunosuppressed, however, increased incidence has been associated with the introduction of immunosuppressant monoclonal antibody therapies such as natalizumab, efalizumab, and rituximab for the treatment of various autoimmune disorders.

CT head can show single or multiple multifocal lesions which usually do not enhance. An MRI is the gold-standard imaging choice, revealing high-signal demyelinating white matter lesions.

Prognosis is very poor, associated with neurological disability and if left untreated, is usually fatal within one year. Treatment focuses on reversing the immune deficiency of the patient to slow or stop the progression of PML. In patients with HIV, treatment involves starting antiretroviral therapies (ART) to increase the patient’s CD4+ count to assist in halting the progression of the infection.

Progressive Multifocal Leukoencephalopathy on MRI brain.

Image Source: Wikimedia Commons (2008). Progressive multifocal leukoencephalopathy 002, Licensed under a creative commons licence. Available for free at: https://commons.wikimedia.org/wiki/File:Progressive_multifocal_leukoencephalopathy_002.jpg (Accessed on: 30 January 2023).

Spinal Tumours

Types of Spinal Tumours

Spinal tumours can be classified according to their location within the spine:

• Intramedullary tumour – located inside the spinal cord (5% of spinal tumours; the majority are ependymomas and astrocytomas, but also include haemangioblastomas).
• Intradural-extramedullary tumour – located inside the dura but outside of spinal cord. (40% of spinal tumours; these mostly consist of meningiomas and peripheral nerve sheath tumours).
• Extradural tumour – located outside the dura, e.g. in the bones, discs and paraspinal soft tissues (55% of spinal tumours, the majority of which are metastases from other systemic cancers).

In MRCP 1, you are not expected to be able to differentiate the different subtypes, however, a brief knowledge of their aetiology is useful.

Ependymomas

Ependymomas are a subtype of gliomas. These cells line the fluid-filled ventricles in the brain and the centre of the spinal cord. Ependymomas are linked to the autosomal dominant disease, neurofibromatosis type 2 (NF2).

Ependymomas

Image Source: Wikimedia Commons (2008). NF2 multiple intramedullary ependymomas 002, Licensed under a creative commons licence. Available for free at: https://commons.wikimedia.org/wiki/File:NF2_multiple_intramedullary_ependymomas_002.jpg (Accessed on: 30 January 2023).

Astrocytoma

Astrocytomas of the spinal cord are, in general, lower grade histologically than brain astrocytomas. They can be associated with neurofibromatosis type 1 (NF1). They are faster growing than ependymomas and the prognosis is worse. Surgery is the usual treatment choice, however, complete resection is rare due to their infiltrative nature. Radiotherapy and/or chemotherapy may also be used.

Haemangioblastomas

Haemangioblastomas are the third most common intramedullary spinal cord tumour, after ependymomas and astrocytomas. As with cerebellar haemangioblastomas, these are benign vascular tumours. They can be associated with Von Hippel-Lindau syndrome, as described earlier in this section. They are slow-growing and can be resected surgically. Endovascular embolisation may be required prior to surgical resection to minimise blood loss during surgery.

Haemangioblastoma.

Image Source: Wikimedia Commons (2007). Hippel Lindau, Licensed under a creative commons licence. Available for free at: https://commons.wikimedia.org/wiki/File:Hippel_Lindau.gif (Accessed on: 30 January 2023).

Meningiomas

A meningioma is a tumour that arises from the meninges. The meninges are membranes that cover and protect the brain and the spinal cord. There are three meningeal layers: dura mater; arachnoid mater; pia mater.

Risk factors include previous high dose ionising radiation and previous trauma. There is also an association with neurofibromatosis type 2.

Spinal meningioma on MRI.

Image Source: Wikimedia Commons (2009). Meningeom im Spinalkanal MRT, Licensed under a creative commons licence. Available for free at: https://commons.wikimedia.org/wiki/File:Meningeom_im_Spinalkanal_MRT.jpg (Accessed on: 30 January 2023).

Investigation and Management 

A full neurological examination followed by imaging is required in all presentations suspicious of a possible spinal lesion. MRI can be used to identify spinal pathologies and aid diagnosis by distinguishing characteristics of the lesion. MRI can also be useful in prognostication and neurosurgical planning.

Whole spine MRI is the first line imaging choice to investigate patients with new back pain with focal neurology, or other red flag features, particularly in those with a history of cancer. If a possible spinal malignancy is identified, a CT chest/abdomen/pelvis is useful for staging to identify any primary lesion or other metastases. Biopsies may be taken for histological diagnosis.

Management of the lesion depends on its aetiology. If there is evidence of metastatic cord compression, the management is with flat bed rest, high-dose dexamethasone with PPI cover, and urgent discussion with clinical oncology for consideration of radiotherapy to the affected area.

The neurosurgical MDT (neurologists, neurosurgeons/spinal surgeons, oncologists, psychologists, neuroradiologists and specialist nurses) are essential in making management decisions and supporting the patient through their diagnosis.