L18 Space occupying lesions

• Space occupying lesions (SOLs)

  Lesions that take up space and add volume to the cranial cavity
• Types of SOLs


  • Tumours (primary, secondary, parasitic)
  • Trauma (subdural haematoma, extra-dural haematoma)
  • Vascular (aneurysms)
  • Inflammatory (abscess, syphilitic gumma)
• Increased intracranial pressure (ICP)

  • The intracranial space contains the brain, blood and CSF (cerebrospinal fluid)
  • The skull is not able to be distended
  • Increased in volume will have an effect

  
• Evidence of increased ICP

  • Cisterns, ventricles and sulci become effaced
  • Edema around the mass
  • Midline shift
  • Ventricular compression
• Brain haemorrhage can be caused by head trauma, high blood pressure, blood vessel abnormalities, blood or bleeding disorder, liver disease, or brain tumours
• Epidural haematoma


  • Collection between the dura and arachnoid matter
  • Can cross suture lines
  • Crescent shaped hematoma

  
• Subdural haematoma


  • Sub Acute
  • Damage to bridging veins
  • Venus blood
  • Older Adults

  
• Intracerebral haematoma


  Within the brain parenchyma

  
• Intracerebral haematoma


  • 'Dancing man' sign
  • Bleeding into the subarachnoid space
• Subarachnoid haemorrhage


  • Head trauma
  • Ruptured berry aneurysm
  • Thunderclap headache
• Effects of herniation


  • Displaced brain tissue (subfalcine, uncal, tonsillar)
  • Right pupillary dilation
  • Decreased movement on the left side
  • Compression of key structures (uncal herniation pressure on the midbrain, tonsillar herniation compression of the cerebellum and medulla)

  
• Cerebral perfusion pressure (CPP)


  Mean arterial pressure - ICP
• Clinical presentation of SOLs

  • General (non-local) symptoms and signs (headache, nausea, vomiting, disturbed consciousness level, papilledema, dilated fixed pupil, weakness, seizures)
  • Focal (local) symptoms and signs (depend on size and location of mass)
• Meningioma


  • Benign tumour that compresses but does not usually invade the underlying brain
  • Most are Grade I
  • More common in women over 40
  • Exhibit a wide range of histologic appearances
  • Those more likely to recur or be aggressive are placed into WHO II and III

  
• Meningioma


  • Solitary
  • Nicely-defined
  • Slow growing
  • Surgery works
• Meningioma complications


  • Increased compression of cranial cavity
  • Increased edema (40-60% of cases)
  • Increased intracranial pressure
  • Herniation

  
• Pituitary tumours


  • Non-functioning pituitary adenomas (benign glandular tumour often present as SOLs)
  • Symptoms associated are those related to increased ICP and others related to their location

  
• Glioblastoma


  • Most frequent and deadliest of the primary brain tumours
  • 60-75% of astrocytomas
  • Most malignant astrocytoma
  • Found most commonly in adults
  • Poor prognosis-median survival 14 months
  • 5 year survival rate 4%
  • In New Zealand 126 people will die from this disease each year
  • Mean age is approximately 62 years old
  • 80% of patients will be over 50 years of age
• Glioblastoma


  • Highly infiltrative
  • Poorly defined margins
  • Rapid growing
  • Surgery helps
  • Increased ICP
  • Herniation
  • Additional complications

  
• Most common tumours to metastasize to the brain

  • Lung
  • Melanoma
  • Breast
  • Renal
  • Colorectal
• Vasogenic edema


  • Disruption of the blood brain barrier
  • Extracellular accumulation of fluid
  • Extravasation of serum proteins

  
• Cytotoxic edema


  • Intracellular accumulation of fluid and Na+
  • Cell swelling
  • Disruption of osmotic pressure
  • Increase fluid from blood vessels but BBB stays intact

  
• Abscess


  • Blood-borne spread from distal locations
  • Septic emboli in the brain- e.g. myocardial endocarditis
  • Extension from local infections (ear infection, dental abscess, paranasal sinuses infection)
  • Direct from trauma
• Abscess


  • Cavities filled with pus, surrounded by edema
• Healing in the brain involves gliosis, cavity formation, and lost tissue does not regenerate