Childhood brain tumours

Question 1

What are the 5 childhood brain tumours?

Answer 1

• Pilocytic astrocytoma
• Medulloblastoma
• Ependymoma
• Craniopharyngioma
• Pinealoma

Question 2

What is the most common childhood brain tumour?

Answer 2

Pilocytic astrocytoma

Question 3

Where are pilocytic astrocytomas found?

Answer 3

Posterior fossa (cerebellum)
- May be supratentorial

Question 4

Describe pilocytic astrocytoma on histology

Answer 4

• Astrocye origin GFAP +ve
• Bipolar neoplastic cells with hair-like projection
• Associated with microcysts and Rosenthal fibers (eosinophilic corkscrew fibers)

Question 5

What do pilocytic astrocytomas look like grossly?

Answer 5

Cystic + solid

Question 6

What childhood tumour is GFAP +ve?

Answer 6

Pilocytic astrocytoma

Question 7

What childhood brain tumours may compress the 4th ventricle causing hydrocephalus?

Answer 7

• Medulloblastoma
• Ependymoma
• Pinealoma is from cerebral aqueduct compression

Question 8

What is the most common malignant brain tumour in children?
Where can the tumour metastasise to?

Answer 8

Medulloblastoma
- “Drop metastases” to spinal cord

Question 9

What childhood brain tumour may cause hydrocephalus and truncal ataxia (cerebellar vermis affected)?

Answer 9

Medulloblastoma

Question 10

What are the features of Medulloblastoma on histology?

Answer 10

Primitive ectodermal tumour
- Homer-Wright rosettes
- Small blue cells
- Synaptophysin +ve

Question 11

Where are ependymomas most commonly found?

Answer 11

4th ventricle

Question 12

Describe the histology of Ependymomas

Answer 12

• Perivascular pseudorosettes
• Rod-shaped blepharoplasts (basal ciliary bodies) found near nucleus

Question 13

What is the most coomon childhood supratentorial tumour?

Answer 13

Craniopharyngioma

Question 14

What childhood brain tumour is associated with bitemporal hemianopia?

Answer 14

Cranopharyngioma

Question 15

What childhood brain tumour is derived from remnants of Rathke’s pouch (ectodrrm)?

Answer 15

Craniopharyngioma

Question 16

Desribe the histology of Craniopharyngioma?

Answer 16

• Calcification
  -Cholesterol crystals found in ‘motor oil’ like fluid within tumour

Question 17

What are the 3 main symptoms of Pinealoma?

Answer 17

• Parinaud syndrome (compression of tectum -> vertical gaze palsy)
• Obstructive hydrocephalus (compression of cerebral aqueduct)
• Precorious puberty in males due to hCG production

Question 18

What tumours are similar to pinealomas?

Answer 18

Similar to germ cell tumours (eg testicular seminomas)

Question 19

How can pinealomas cause vertical gaze palsy?

Answer 19

Tumour compresses mesencephalic tectum, including the superior colliculus adjacent oculomotor (origin of cranial nerve III) and Edinger-Westphal nuclei, causing dysfunction to the motor function of the eye

Question 20

Perivascular pseudorosettes and rod-shaped blepharoplasts are found near the nucleus are found in what tumour?

Answer 20

Ependymoma

Question 21

Homer-Wright rosettes and small blue cells are found in what tumour?

Answer 21

Medulloblastomas