Most Common Brain Tumour in Adults
When all brain tumours (primary and secondary) are considered together, cerebral (brain) metastases are the most common brain tumours encountered in adults — they outnumber all primary brain tumours combined. Metastatic deposits most frequently arise from primary cancers of the lung, breast, kidney (renal cell carcinoma), skin (melanoma), and colon, and typically present as single or multiple well-circumscribed lesions at the grey-white matter junction.
Analysis of Options
- Pituitary tumour: Pituitary adenomas are common among primary brain tumours (roughly the second or third most common primary intracranial tumour), but they are far less frequent than metastatic deposits when all brain tumours are considered together. They are not the overall most common brain tumour in adults.
- Glioma: Gliomas (including astrocytomas and glioblastoma) are the most common primary malignant brain tumour in adults, but again, metastatic tumours as a group are more numerous than gliomas when all brain tumours are counted.
- Cerebral metastasis: As explained above, secondary (metastatic) tumours to the brain are more common than any single type of primary brain tumour, making this the correct answer.
- Vestibular schwannoma: This is a benign tumour of the vestibulocochlear (8th cranial) nerve, classically presenting with unilateral sensorineural hearing loss and tinnitus. It is a relatively uncommon primary intracranial tumour and is clearly not the most common brain tumour overall.
Conclusion
Considering all brain tumours together — not just primary ones — cerebral metastasis is the most common brain tumour in adults, making it the correct answer.
Important Questions from Brain & Nervous System Surgery
Which of the following chromosomal abnormalities are associated with brain tumours?
1. Neurofibromatosis type 1
2. Neurofibromatosis type 2
3. Peutz-Jeghers syndrome
4. Hereditary nonpolyposis colorectal cancer
Select the correct answer using the code given below.
Consider the following clinical features:
1. Raised ICP
2. Seizures
3. Focal deficit
4. Headache
Which of the above clinical features are related to most brain tumours?
- The most common type of brain tumours associated with neurofibromatosis type 1 brain tumour syndrome is
Upper motor neuron lesions are characterized by which of the following?
1. Increased tone spasticity
2. Hyperreflexia
3. Absent plantar response
4. Motor weakness
Select the correct answer using the code given below.
A comatose patient after sustaining severe head injury has been admitted in neurosurgical ICU. Which of the following parameters should ideally be maintained in this patient ?
1. $pCO_2 = 4.5 – 5.0$ kPa ($33-38$ mm Hg)
2. MAP = $80 – 90$ mm of Hg
3. $pO_2 > 11$ kPa ($> 80$ mm Hg)
4. $Na^+ < 130$ meq/L
Select the correct answer using the code given below :
