brain tumor

Brain Tumours

  • Primary brain tumours account for 2% of all cancer deaths.

  • Estimated 3,000 new cases and 2,100 deaths from brain and spinal cord cancers in 2015.

  • 20% to 40% of intracranial tumours are metastatic.

  • Incidence increases with age, with a majority found in people aged 50-70.

  • Brain tumours in children and adolescents are the second most common neoplasm in Canada.

Types of Tumours

  • Brain tumours have different histology, site of origin, prognosis, and treatment.

  • Malignant term used for lack of cell differentiation, invasiveness, and metastasis.

  • Benign and malignant terms do not apply in the same sense as in other body parts.

  • Difficulty in total resection due to infiltration of normal brain tissue by benign tumours.

  • Brain tumours rarely metastasize outside the CNS.

Glial Tumours

  • Divided into astrocytic and oligodendroglial categories.

  • Astrocytic tumours further classified into fibrillary and pilocytic astrocytomas.

  • Fibrillary astrocytomas are common in adults, with different grades based on anaplasia.

  • Pilocytic astrocytomas occur in children and young adults, usually in the cerebellum.

  • Oligodendrogliomas represent 5% to 18% of glial tumours, common in middle life.

Ependymomas

  • Derived from the epithelium lining ventricles and spinal canal.

  • Most likely to occur under the age of 5, affecting the fourth ventricle.

  • Clinical features depend on the neoplasm's location.

Meningiomas

  • Develop from meningothelial cells of the arachnoid outside the brain.

  • Slow-growing, well-circumscribed, often benign tumours.

  • Complete removal possible if the tumour does not involve vital structures.

Primary Central Nervous System Lymphomas

  • Deep, periventricular, and diffuse tumours common in immunocompromised patients.

  • Associated with Epstein–Barr virus, accounting for 3% of all CNS tumours.

  • Common symptoms include behavioral and cognitive changes, hemiparesis, aphasia, visual field deficits, and seizures.

Etiology

  • The etiology of brain tumours is largely unknown.

  • Only ionizing radiation and immunosuppression have shown a relationship to brain cancer.

  • High-dose irradiation for treating intracranial and extracranial cancers is a risk factor.

Main Ideas from Transcript

Page 4

  • Factors contributing to brain tumors:

    • Leukemia, immunosuppression, hereditary factors

  • Manifestations of intracranial tumors:

    • Focal disturbances, increased intracranial pressure (ICP)

    • Types of brain tumors: intra-axial and extra-axial

  • Clinical manifestations of brain tumors:

    • Headache, nausea, vomiting, mental changes, visual disturbances, seizures

    • Increased ICP, cerebral edema, obstruction of CSF flow

  • Effects of brain tumors on brain function:

    • Compression, brain displacement, herniation

Page 5

  • Symptoms associated with brain tumors:

    • Headache, vomiting, papilledema, visual disturbances

    • Personality and mental changes, focal signs and symptoms

  • Diagnosis of brain tumors:

    • Relies on MRI, gadolinium-enhanced MRI for localization

    • EEG, cerebral angiography, PET scan for additional information

  • Treatment options for brain tumors:

    • Surgery, irradiation, medications

    • Advancements in surgical techniques, stereotactic surgery, gamma knife

    • Limitations of radiation therapy in young children

Page 6

  • Diagnosis of brain tumour]===:

    • MRI as the main diagnostic tool, CT scans may miss certain tumors

    • EEG abnormalities in brain tumor patients

  • Treatment of brain tumors:

    • Surgery for diagnosis and tumor removal

    • Role of microsurgical neuroanatomy, stereotactic surgery, ultrasonographic technology

    • External irradiation for malignant tumors, gamma knife technique

    • Limitations of radiation therapy in young children

  • Medications and future therapies for brain tumors:

    • Challenges with blood-brain barrier for chemotherapy

    • Development of targeted therapies based on genetic features and molecular profiles of tumors

Page 8: Summary of Infections and Brain Tumors

  • Classifying CNS Infections

    • Infections can be classified based on structures involved (e.g., meningitis, encephalitis) or the type of organism causing the infection.

    • Infections can lead to complications like hydrocephalus, seizures, and other neurologic defects.

  • Brain Tumors

    • Account for 2% of all cancer deaths and are the second most common cancer in children.

    • Can originate from intracranial structures or metastasize from other parts of the body.

    • Primary brain tumors can develop in various cranial cavity structures.

    • Cause focal disturbances in brain function and increased intracranial pressure.

    • Clinical manifestations depend on tumor size and location, including headache, nausea, vomiting, mental changes, visual disturbances, and seizures.

  • Diagnostic Tests

    • Physical examination, visual field testing, funduscopic examination, CT scans, MRI studies, EEG, and cerebral angiography are used for diagnosis.

  • Treatment

    • Involves surgery, irradiation and medication