CNS Tumors and Space Occupying Lesions

Question 1

What features are unique to CNS Tumors?

Answer 1

1. do not have morphologically evident premalignant or in situ stages
2. even low grade lesions may infiltrate large regions of brain, leading to serious clinical deficits
3. intracranial pathologies produce life threatening of ICP
4. they arise from a progenitor cells that preferentially differentiates down one cellular lineage
5. anatomic site can influence outcome independent of histological classification
6. rarely spread outside CNS
7. ~ 1/2- 3/4 are primary
8. account for 20% of all pediatric tumors
9. Many typically occur in certain anatomic regions of brain, with characteristic age distribution and clinical course
10. Childhood CNS tumors differ from those in adults in both histologic subtype and location.

Question 2

Embryonal tumors

Answer 2

Medulloblastoma, Neuroblastoma

Question 3

Tumors of Glial cells

Answer 3

Glioma

1. Astrocytoma
2. Glioblastoma
3. Oligodendroma
4. Ependymoma

Question 4

What are the most common tumors of children?

Answer 4

Astrocytoma

Medulloblastoma

Pontine Glioma

Question 5

What is the most common adult tumors?

Answer 5

Meningoma

Gliomas [Astrocytoma, Oligodendrogliomas, Glioblastoma]

Question 6

What are extrinsic brain tumors?

Answer 6

Tumors of the meninges, cranial roots and spinal nerve roots

• Meningioma
• Schwannoma
• Neurofibroma

Question 7

What are instrinic brain tumors?

Answer 7

tumors of glial origin

• Astrocytoma
• Glioblastoma
• Oligodendrogliomas
• Ependymoma
• Choroid plexus papilloma
• PNET- Medulloblastoma
• Hemangioblastoma
• Lymphoma

Question 8

Epidemiology of CNS tumors

Answer 8

1. accounts of 10% of all tumors
2. 2nd commonest tumor in children, 6th in adults
3. Peak incidence at 1st and 5th decades
4. Adults - 70% supratentorial – Intrinsic + extrinsic
5. Children - 70% infratentorial – Intrinsic
6. No/very rare extra-neural spread.
7. Metastasis most common.

Question 9

What is a common presenting feature of a patient with a posterior fossa tumor?

Answer 9

Hydrocephalus, particularly in children

Question 10

What are common presenting features of a patient with tumor in the parietal lobe?

Answer 10

1. Sensory deficits
2. Paresthesia
3. Loss of two-point differentiation
4. Visual field deficits

Question 11

What are common presenting features of a patient with tumor in the temporal lobe?

Answer 11

Psychomotor seizures

temporal lobe-judgment, behavior, hallucinations, visceral symptoms, no convulsions, but loss of consciousness

Question 12

What are common presenting features of a patient with tumor in the occipital lobe?

Answer 12

Visual disturbances

Question 13

What are common presenting features of a patient with tumor in the Frontal lobe?

Answer 13

1. Inappropriate behavior
2. Personality changes
3. Inability to concentrate
4. Impaired judgment
5. Memory loss
6. Headache
7. Expressive aphasia
8. Motor dysfunctions

Question 14

What are common presenting features of a patient with tumor in the cerebellum?

Answer 14

Incoordination and dysequilibrium

Question 15

What is the gold standard for investgating CNS tumors?

Answer 15

MRI with gadolinium contrast is the gold standard

Question 16

What conditions are diagnosed by Lumbar puncture?

[basically what are the indications of LP]

Answer 16

1. Medulloblastoma
2. Ependymoma
3. Germ cell tumors

Question 17

What are the contraindications for LP?

Answer 17

Newly dx hydrocephalous sec. to CSF flow obstruction, tumour causing supratentorial midline shift & infratentorial tumours

Question 18

Why is MRI preferred over CT when diagnosing CNS tumors?

Answer 18

1.