Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

FRCS Part 2 > Paediatric tumours > Flashcards

Paediatric tumours Flashcards

1
Q

Commonest glioma in paediatric patients?

A

Pilocytic astrocytoma

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

What is the commonest genetic abnormality in pilocytic astrocytomas?

A

BRAF mutation (which activates MAPK pathway) 15-20% of NF1 patients also have pilocytics (more commonly optic gliomas)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

What are the histological appearance of pilocytic astrocytomas?

A

2 main cell populations; 1) cells with long thin bipolar processes (resembling hairs—hence pilocytic) with Rosenthal fibers. 2) loosely knit tissue comprising stellate astrocytes with microcysts and occasional eosinophilic granular bodies. Histology alone may be inadequate for diagnosis.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

What is the radiological appearance of a pilocytic astrocytoma?

A

66% have an enhancing nodule with a cyst. Can also be necrotic centre or no cyst at all.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

When would you give radiotherapy to a pilocytic astrocytoma?

A

Only for recurrence with malignant histology or if recurrence is non-resectable (surgery is preferred treatment)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

What is the diencephalic syndrome?

A

A rare syndrome seen in paeds, usually caused by infiltrating glioma into the anterior hypothalamus:

Cachexia/Failure to thrive

Hyperactivity

Euphoric affect

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

When do you operate on brainstem gliomas?

A

Hydrocephalus (shunt)

Dorsally exophytic tumours as these are generally benign (e.g. ganglioglomas and amenable to radical subtotal resection)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

What feature makes a pleomorphic xanthoastrocytoma go from grade 2 to 3 (anaplastic)

A

>5 mitotic figures on high power field or necrosis

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

Where do myxopapillary ependymomas occur, what grade are they?

A

Filum terminale, WHO grade 1

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

Where is the most likely location for an adult ependymoma?

A

Intramedullary, arising from the central canal of the spinal cord. Histologically they are thought to arise from radial glial cells.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

Where do ependymomas occur in children (most commonly)?

A

Posterior fossa

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

What post-op investigation must be done following resection of an ependymoma specifically?

A

LP for cytology to check for drop mets ~2 weeks post-op. This is prognostic!

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

How do you differentiate radiologically between ependymoma and medulloblastoma?

A

4th ventricle drapes around medulloblastoma ( “banana sign”) from the anterior aspect, c.f. ependymoma which tends to grow into 4th ventricle from the floor. Ependymoma may grow through foramen of Luschka and/or Magendie (plastic). Ependymomas tend to be inhomogeneous on T1WI MRI (unlike MB) the exophytic component of ependymomas tends to be high signal on T2WI MRI (with MB this is only mildly hyperintense) calcifications: common in ependymomas, but only in < 10% of MB

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

Would you give radiotherapy to a completely resected ependymoma?

A

Yes. Significant improvement in survival adjuvant radiotherapy to surgical bed. (recent recommendation for 59.4Gy +1cm margin)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

How would a positive LP for cytology in ependymoma change the management plan?

A

Likely to give whole spine radiotherapy

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

Which type of ependymoma is most common in the spinal cord?

A

Tanycytic ependymoma

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

What grade is a myxopapillary ependymoma?

A

Grade 1 filum terminale tumour All other ependymomas grade 2 or 3

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

What are the different grades of choroid plexus tumours?

A

Grade 1 - Choroid plexus papilloma

Grade 2 - Atypical CPP

Grade 3 - Choroid plexus carcinoma

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

What is the gene associated with choroid plexus papilloma?

A

Gene for potassium channel KIR7.1

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

Where do choroid plexus papillomas tend to occur in children?

A

Supratentorial, lateral ventricle, more so on left. In adults more likely to occur infratentorial

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

How do you differentiate between grade 1 and 2 choroid plexus papilloma?

A

More mitotic figures (≥ 2 mitoses per 10 randomly selected HPFs) without frank signs of malignancy seen in choroid plexus carcinoma up to 2 of the following 4 features may be observed: increased cellularity, nuclear pleomorphism, blurring of the papillary pattern (solid growth) and areas of necrosis. They are more likely to recur than their grade I counterparts.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

What are the histological features of a choroid plexus carcinoma?

A

Choroid plexus carcinoma (CPC) show at least 4 of the 5 following features: 1. frequent mitoses: usually > 5 mitoses per 10 HPF 2. increased cellular density 3. nuclear pleomorphism 4. blurring of the papillary pattern with poorly structured sheets of tumor cells 5. necrosis

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

What grade is a DNET?

A

WHO grade 1

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

What are the most common locations for pilocytic astrocytomas?

A

Cerebellar hemisphere

Optic nerve

Hypothalamus

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

What is the principle CNS tumour associated with NF1?

A

Pilocytic astrocytoma

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
26
Q

What condition is associated with OPGs?

A

NF1

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
27
Q

What % of NF1 patients develop a pilocytic astrocytoma?

A

20%

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
28
Q

What is the surgical goal in pilocytic astrocytoma?

A

Resection of the solid nodule component only. Removal fo the cyst wall is not necessary.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
29
Q

What are the imaging features of an OPG?

A

Uniform dilation of the optic nerve extending >1 cm in length.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
30
Q

How would you approach an OPG surgically?

A

Single optic nerve involvement causing proptosis and visual loss should be managed transcranially with resection from the back of the globe to the chiasm. This causes a junctional scotoma = monocular visual loss + superior temporal quadrantanopia in the contralateral eye due to damage to the knee of wilbrand.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
31
Q

What adjuvent treatment do you given for OPGs?

A

Chemotherapy. Radiotherapy is avoided unless there is tumour post-op/recurrence or if it is malignant

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
32
Q

How do hypothalamic gliomas present?

A

Diencephalic syndrome (cachexia, hyperactivity and euphoric affect)

Endocrine disturbances (hypoglycaemia, DI and precocious puberty)

Hydrocephalus (headache, nausea/vomiting and macrocephaly)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
33
Q

How do brainstem gliomas present?

A

Upper = cerebellar symptoms (ataxia / gait disturbance) and hydrocephalus

Lower = multiple cranial nerve deficits (diplopia / facial weakness / bulbar signs) and long tract findings (weakness)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
34
Q

What are the growth patterns of brainstem gliomas?

A

Diffuse

Cervicomedullary

Focal

Dorsally exophytic

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
35
Q

How do you treat brainstem gliomas?

A

Surgery if dorsally exophytic

Temozolomide may help in paeds

Radiotherapy and steroids

Most die within 6-12 monmths of diagnosis

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
36
Q

What are the clinical features of a tectal glioma?

A

Diplopia

Visual field defect

Nystagmus

Parinaud’s syndrome

Ataxia

Seizures

Hydrocephalus

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
37
Q

What are tectal gliomas histologically?

A

Pilocytic astrocytomas

Diffuse astrocytomas

Ependymomas

Oligodendrogliomas

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
38
Q

What are the treatment options for tectal gliomas?

A

VP shunt or ETV (allows biopsy if needed)
SRS if tumour progression (20%)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
39
Q

What are pilomyxoid astrocytomas?

A

Variants of pilocytic astrocytomas. These have no WHO grade. They are more aggressive, more likely to recur and spread in the CSF.

Histologically does not contain rosenthal fibres or eosinophilic granular bodies.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
40
Q

What are Rosenthal fibres?

A

Eosinophilic cytoplasmic inclusions

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
41
Q

What are the important features of PXAs?

A

WHO grade 2

Superficial location (thought to arise from subpial astrocytes)

>90% are supratentorial

Mural nodule with cyst in 25%

Involve the meninges in 2/3 of cases

Well circumscribed and lipid laden

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
42
Q

What genetic mutation is common with PXA?

A

BRAF V600E

IDH-mutant

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
43
Q

What is the typical location of a SEGA?

A

Arises from the lateral wall of the ventricle adjacent to the foramen of monroe

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
44
Q

What is the mainstay of treatment for PXAs?

A

Gross total resection - 5 y survival 80%

No role for radiotherapy or chemotherapy

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
45
Q

What are the key features of subependymomas?

A

WHO grade 1

Arise from the ependyma protruding into the ventricle

Mostly incidental and do not need intervention, rarely cause hydrocephalus.

Unlike ependymomas, these are NON-enhancing

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
46
Q

Is there are link between progression free survival and WHO grading of ependymoma?

A

Nope

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
47
Q

What are the histological findings with an ependymoma?

A

Often fibrillary with epithelial appearances. Perivascular pseudorosettes or true rosettes are seen with the papillary form.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
48
Q

What is the most common location presentation of a 4th ventricular ependymoma?

A

Obstructive hydrocephalus and CN 6 & 7 palsy

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
49
Q

What are the main differential diagnoses of a posterior fossa mass in a child?

A

Pilocytic astrocytoma (35%)

Medulloblastoma (30%)

Ependymoma (10%)

Haemangioblastoma (2%)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
50
Q

Why do you get CN6 and 7 palsies with posterior fossa tumours?

A

As they compress the facial colliculus in the floor of the 4th ventricle which compresses the CN6 nucleus and the CN7 axons.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
51
Q

What structure lies beneath the striae medullaris in the floor of the 4th ventricle?

A

The facial nerve fibres as they run from the facial nucleus laterally to war around the the abducent nucleus medially. The lower part of the striae medullaris covers the vestibulocochlear fibres.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
52
Q

Why is it difficult to get a complete resection with post-fossa ependymomas?

A

As they tend to invade the obex making complete resection impossible. This results in a worse prognosis.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
53
Q

Where do ependymomas arise from?

A

The floor of the 4th ventricle (compared to medulloblastomas that arise from the roof!)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
54
Q

What cardiac side-effect may occur with ependymomas that extend through foramen of luschka?

A

Bradycardia

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
55
Q

What adjuvent therapy is following resection of ependymomas?

A

Radiotherapy. This improved median survival time by 2 years.(not given if <3 years old).

No role for chemotherapy

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
56
Q

What are the main morbidities with operating on 4th ventricular ependymomas?

A

Need for NG tube and tracheostomy due to involvement of the floor of the 4th.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
57
Q

What are the histological subtypes of ependymoma?

A

WHO grade 1 = Subependymoma / myxopapillary ependymoma

WHO grade 2 = Papillary, clear cell, tanycytic and RELA fusion positive

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
58
Q

Which tumour types are composed of papillae histologically?

A

Choroid plexus papillomas (have a basement membrane) and papillary ependymomas (no basement membrane)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
59
Q

Which ependymoma subtypes can be mistaken histologically for gliomas?

A

Clear cell can be mistaken for oligodendrogliomas

Tanycytic can be mistaken for pilocytic astrocytomas

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
60
Q

Which ependymoma subtype has the worse prognosis?

A

RELA-fusion positive (WHO grade 2-3). Present in 70% of supratentorial ependymomas and almost none of the infratentorial.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
61
Q

Which type of glioma classically arises from the hypothalamus and protrudes into the 3rd ventricle?

A

Chordoid glioma of the 3rd ventricle (WHO 2)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
62
Q

What are the most common locations for CPPs?

A

Lateral ventricle, 4th ventricle and CPA. Note mostly infratentorial in adults and supratentorial with a predilection for the left side in paeds.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
63
Q

What are the histological findings in CPP?

A

Normal choroid plexus with little or no mitotic activity. Most cells are + for the gene that encodes the potassium channel KIR7.1 protein.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
64
Q

What proportion of choroid plexus papillomas arise below the age of 2 years?

A

70%

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
65
Q

Why do subdural collections occur following resection of choroid plexus papillomas?

A

Due to persistent ventriculosubdural fistulas that may require shunting

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
66
Q

What are the imaging features of a DNET?

A

Hypo T1, Hyper T2, partial FLAIR suppression & no contrast enhancement.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
67
Q

What are the imaging features of a ganglioglioma?

A

Gangliogliomas (WHO grade 1)

Iso T1 with bright contrast enhancement, and Iso/hyper T2. Due to calcification may show blooming on GRE

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
68
Q

What are the histological features of gangliogliomas?

A

Contain neoplastic cells of neuronal and glial components.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
69
Q

What is the treatment for gangliogliomas?

A

Complete surgical resection

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
70
Q

What is Lhermitte Duclos disease?

A

Dysplastic cerebellar gangliocytoma = hamartoma of the cerebellum (strongly associated with Cowden syndrome)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
71
Q

What grade are central neurocytomas?

A

WHO grade 2

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
72
Q

Where are central neurocytomas attached to?

A

The septum pellucidum.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
73
Q

What is the management of central neurocytomas?

A

Gross total resection.

If Ki-67 is elevated then radiotherapy after subtotal resection may reduce recurrence.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
74
Q

What are the histological features of a central neurocytoma?

A

Similar to oligos with a fried egg appearance on H&E staining. Staining is positive for synaptophysin and Neu-N showing neuronal lineage compared to oligos which are GFAP positive. There is also no 1p19q mutation.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
75
Q

What is a cerebellar liponeurocytoma?

A

WHO grade 2 lesion that occurs in the cerebellum of adults with neuroplastic neurocytes that resemble adipocytes.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
76
Q

What are paragangliomas?

A

Aka glomus tumours / phaeochromocytomas. These are WHO grade 1 neuroendocrine tumours that arise from neural crest cells. These occur in the filum terminale or the jugular foramen.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
77
Q

What do glomus tumours secrete?

A

Adrenaline and noradrenaline which may cause life-threatening hypertension and arrhythmias.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
78
Q

What condition are phaeochromocytomas associated with?

A

VHL, MEN2a/2b and NF1

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
79
Q

Which patients with phaeochromocytomas should undergo genetic testing?

A

If <50 years at the time of diagnosis

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
80
Q

What lab investigations should be performed in patients with suspected phaeochromocytomas?

A

Plasma fractionated meta-nephrines (replaces VMAs). Urine total catecholamines and meta-nephrines. If raised then a clonidine suppression test can be done which should cause a fall <50% in normal cases but will not change with phaeos!

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
81
Q

What is this?

A

Carotid body tumour (aka chemodectoma)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
82
Q

What is the term given to a glomus tumour with middle ear invasion?

A

Glomus tympanicum

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
83
Q

What is carcinoid/seratonin syndrome?

A

Bronchoconstriction, abdominal pain, diarrhoea, headache, flushing, hypertension and hyperglycaemia. Occurs with glomus tumours due to seratonin release.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
84
Q

What grading system is used for glomus tumours?

A

Modified Jackson classification:

1 - Small, limited to jugular bulb, middle ear and mastoid

2 - Extends under the IAC

3 - Extends to petrous apex

4 - Extends into clivus / infratemporal fossa

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
85
Q

What pre-op meds should be given before GA in glomus tumours?

A

Alpha blocker - Phenoxybenzamine to prevent periph vasoconstriction.

Beta blocker - Propanolol

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
86
Q

What is the treatment for glomus tumours?

A

Surgical resection through the neck +/- pre-op embolisation. Often the IJV is sacrificed.

Radiation / SRS if surgery not possible.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
87
Q

What is interhemispheric transcallosal schizencephaly?

A

This a developmental abnormality where there is a connection between cortical gray matter and ventricle ependymal cells.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
88
Q

A young child presents with a 3 month history of clumsiness, slurred speech and headaches. He is found to be ataxic and have poor coordination. Where is the lesion?

A

Cerebellar

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
89
Q

What is the differential diagnosis of a post fossa mass in a child?

A

Medulloblastoma, ependymoma, pilocytic astrocytoma (most common), choroid plexus papilloma and metastasis (rare in children!)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
90
Q

What is the most common infratentorial tumor in childhood?

A

Medulloblastoma accounts for 30% of all infratentorial tumours and is the most common brain tumour in childhood.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
91
Q

Is medulloblastoma more common in males or females?

A

Males 2:1

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
92
Q

What other investigations should be done in a patient with a medulloblastoma?

A

MRI of the whole spine to rule out drop metastasis.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
93
Q

Where do medulloblastomas arise from?

A

The roof of the fourth ventricle.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
94
Q

What are the histological subtypes of medulloblastomas?

A

Classical, desmoplastic, large cell and medulloblastomas with extensive nodularity.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
95
Q

What is the management of medulloblastomas?

A

Maximal surgical resection with chemotherapy and radiotherapy to the whole neuroaxis. Note operative goal is not complete resection due to risk of deficit but maximal resection to reduce the required radiation dose!

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
96
Q

What are the surgical approaches to medulloblastomas?

A

Transvermian, transcortical or telovelocerebellar.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
97
Q

What are the adjuvant treatments required post-resection of a medulloblastoma?

A

Chemotherapy including cisplatin, vincristine, lomustine and cyclophosphamide followed by radiation of the neuroaxis.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
98
Q

What is the dose of radiation given to medulloblastomas?

A

36 Gy to the neuroaxis and further 18Gy to the tumour bed.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
99
Q

What is the prognosis of a standard medulloblastoma?

A

60-80% 5 year progression free survival. If diagnosed

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
100
Q

What grading system is used for prognosis of medulloblastomas?

A

The Chang system: T1 3cm ; T3b Tumour involves the floor of the 4th ventricle; T4 Tumour spreading out of the 4th ventricle or causing severe obstructive hydrocephalus. M0 No tumour cells in the csf; M1 Tumour cells on CSF cytology; M2 Tumour seeding in the cranium; M3 Tumour seeding in the spine; M4 Systemic spread.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
101
Q

A child presents with progressive diplopia and facial asymmetry. What is the diagnosis?

A

Brainstem glioma; (the differential includes medulloblastoma, ependymoma, choroid plexus papilloma and metastases).

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
102
Q

What are the features of a brainstem glioma on imaging?

A

Non-enhancing or slight enhancement hypointense lesion on T1 and hyperintense lesion on T2 resulting in oedema and deformation of the brainstem.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
103
Q

What are does the MR spectroscopy show for a brainstem glioma?

A

Increased choline/creatine ratio and decreased N-acetyl aspartate/creatine ratio within the lesion. The is also the case with a demyelinating lesion.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
104
Q

Why does the patient with a brainstem glioma have a CN6 and CN7 lesion?

A

As there is infiltration of the facial colliculus formed by the CN7 fibres encircling the CN6 nucleus in the dorsum of the pons.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
105
Q

What are the goals of surgery for brainstem gliomas?

A

Decompress the brainstem and get a histological diagnosis.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
106
Q

What is the surgical approach to a brainstem glioma anterior to the floor fourth ventricle?

A

Suboccipital craniotomy and vermis sparing telovelar approach. The infrafacial triangle can then be used to approach the tumour. The infrafacial triangle can be found using mapping or measurement techniques. The area just below the striae medullaris is a good marker for the centre of the infrafacial triangle.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
107
Q

What neurophysiological monitoring should you use intraoperatively?

A

1) Brainstem evoked potentials 2) Sensory evoked potentials 3) Motor evoked potentials and 4) 4th ventricle mapping.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
108
Q

What are the safe entry zones to the fourth ventricle?

A

1) Suprafacial (supraabducent) triangle located above the facial colliculus 5mm off the midline to avoid the MLF and 2) Infrafacial triangle located below the facial colliculus 5mm off the midline to avoid the MLF.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
109
Q

What is the management for a brainstem glioma?

A

Surgery is for brainstem decompression or when a histological diagnosis is needed. Then radiotherapy / GK.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
110
Q

What is the classification of pontine tumours?

A

Diffuse, focal or exophytic. Diffuse are usually malignant and difficult to delineate from neighbouring parenchyma. Any hyperintensity on T1 is usually due to haemorrhage. Focal are well demarcated with low signal intensity on T1 and high on T2. Exophytic are dorsally exophytic into the 4th ventricle and may be benign or malignant.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
111
Q

What structures are present in an axial section through the upper pons?

A

This is at the level of the superior cerebellar peduncle. The upper 4th ventricle can be seen with the pons anterior. The reticular formation is seen at the floor of the 4th ventricle with the medial lemniscus anterior to it. The pyramidal tracts are crossing within the pons.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
112
Q

What structures are present in the axial section through the lower pons?

A

This is at the level of the middle cerebellar peduncle. The facial colliculus is seen as the CN6 nucleus and the CN7 fibres passing around it. Medial to the CN6 nuclei is the MLF. Lateral to the CN6 nucleus is the CN8 nucleus. Anterior to the MLF in the midline is the reticular formation. The trapezoid body lies anterior the reticular formation. The pyramidal tracts have crossed by now.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
113
Q

What structures are present in the axial section through the medulla?

A

This is at the level of the inferior cerebellar peduncle. The CN12 nucleus lies most medial. Lateral to this is the dorsal vagal nucleus. Lateral to this is the nucleus tractus solitarius. Anterior to these 3 nuclei is the nucleus ambiguus. In the midline is the MLF and the medial lemniscus anteriorly. Lateral to the medial lemniscus is the inferior olivary nucleus and inbetween these two runs the fibres of the CN12. Medial to the ION are the pyramids.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
114
Q

What is the differential diagnosis of an enlarged hypodense lesion within the brainstem?

A

Benign brainstem tumours include pilocytic astrocytomas, haemangioblastomas, PXA, ependymoma, choroid plexus papilloma and abscess. Malignant tumours include GBM, metastases and lymphoma.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
115
Q

How should a brainstem lesion be further investigated?

A

MRI+/- contrast, swallowing assessment and vocal cord assessment

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
116
Q

How can pontine tumours be resected?

A

Prone with neck flexion, neuro-navigation with multimodal evoked potential monitoring, entry through the floor of the 4th ventricle where the tumour is visible or through the safe zones (supra / infrafacial triangles). Laterally based lesions can also be accessed via the far lateral approach.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
117
Q

What is the aim of surgery for brainstem tumours?

A

Maximal surgical resection without significant neurological deficit followed by chemo- and radiotherapy. Chemotherapy may reduce the tumour burden with choroid plexus papillomas / ependymomas.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
118
Q

What is the aim of surgery for brainstem tumours?

A

Maximal surgical resection without significant neurological deficit followed by chemo- and radiotherapy. Chemotherapy may reduce the tumour burden with choroid plexus papillomas / ependymomas.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
119
Q

How can pontine tumours be resected?

A

Prone with neck flexion, neuro-navigation with multimodal evoked potential monitoring, entry through the floor of the 4th ventricle where the tumour is visible or through the safe zones (supra / infrafacial triangles). Laterally based lesions can also be accessed via the far lateral approach.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
120
Q

How should a brainstem lesion be further investigated?

A

MRI+/- contrast, swallowing assessment and vocal cord assessment

121
Q

What is the differential diagnosis of an enlarged hypodense lesion within the brainstem?

A

Benign brainstem tumours include pilocytic astrocytomas, haemangioblastomas, PXA, ependymoma, choroid plexus papilloma and abscess. Malignant tumours include GBM, metastases and lymphoma.

122
Q

What structures are present in the axial section through the medulla?

A

This is at the level of the inferior cerebellar peduncle. The CN12 nucleus lies most medial. Lateral to this is the dorsal vagal nucleus. Lateral to this is the nucleus tractus solitarius. Anterior to these 3 nuclei is the nucleus ambiguus. In the midline is the MLF and the medial lemniscus anteriorly. Lateral to the medial lemniscus is the inferior olivary nucleus and inbetween these two runs the fibres of the CN12. Medial to the ION are the pyramids.

123
Q

What structures are present in the axial section through the lower pons?

A

This is at the level of the middle cerebellar peduncle. The facial colliculus is seen as the CN6 nucleus and the CN7 fibres passing around it. Medial to the CN6 nuclei is the MLF. Lateral to the CN6 nucleus is the CN8 nucleus. Anterior to the MLF in the midline is the reticular formation. The trapezoid body lies anterior the reticular formation. The pyramidal tracts have crossed by now.

124
Q

What structures are present in an axial section through the upper pons?

A

This is at the level of the superior cerebellar peduncle. The upper 4th ventricle can be seen with the pons anterior. The reticular formation is seen at the floor of the 4th ventricle with the medial lemniscus anterior to it. The pyramidal tracts are crossing within the pons.

125
Q

What is the commonest pineal region tumour?

A

Germinoma

126
Q

What are the anatomical borders of the pineal region?

A

Superior - splenium of CC and tela choroidea

Inferior - quadrigeminal plate and tectum

Anterior - Back of 3rd ventricle

Posterior - internal cerebral veins and cerebellar vermis

Laterally - pulvinar of the thalamus

127
Q

What is the commonest pineal region tumour over the age of 40?

A

meningioma or glioma

128
Q

How do pineal region germinomas present?

A

Hydrocephalus

Perinauds syndrome (convergence-retraction nystagmus, up-gaze palsy and pseudo-argyll robertson pupil = near-light dissociation of the pupillary response)

Precocious puberty (in boys)

129
Q

Label the structures in the pineal region

A

Splenium

Telechoroidae

Posterior commissure

Habenula commisure

Tectum

Internal cerebral vein > vein of galen

130
Q

Name the veins from lateral to medial in the supracerebellar infratentorial approach.

A

Basal vein of rosenthal (lateral), internal cerebral veins and superior vermian vein

131
Q

What are the histological findings of a pineocytoma?

A

pineocytomatous rosettes of uniform cells and/or pleomorphic cells having gangliocytic differentiation.

132
Q

How are the veins displaced with meningiomas in the pineal region?

A

Inferiorly (whilst pineal tumours displace them upwards!). This should be considered with planning the approach as inferiorly displaced veins will make a supracerebellar infratentorial approach difficult.

133
Q

How do you classify the differential diagnoses for pineal region tumours?

A

By the tissue of origin:

Pineal (pineocytoma, pineoblastoma, pineal tumour of intermediate differentiation and papillary pineal tumours)

Germ cells (germinoma, embryonal carcinoma, teratoma, mixed, yolk sac, choriocarcinomas, teratoma with malignant differentiation - mnemonic = GETMYCT)

Glial (astro/oligo)

Arachnoid (meningiomas / arachnoid cyst)

Ependyma (ependymoma)

Haematogenous (metastases)

Vascular (vein of galen / AVM /lymphoma)

Ectoderm (dermoid / epidermoid)

Infection (cysticercosis)

134
Q

Which pineal region tumours cause drop mets?

A

GCTs, ependymomas and pineoblastomas

135
Q

What is syndrome of the sylvian aqueduct?

A

Parinaud’s syndrome with additional down-gaze palsy

136
Q

Why do pineal region tumour patients look like they have sunsetting?

A

Combination of lid retraction (Collier’s sign) and the upgaze palsy)

137
Q

Why do germ cell tumours cause precocious puberty in boys?

A

Choriocarciomas and germinomas may cause LH release

138
Q

What is suggested by the triad: DI, VFD and panhypopituitarism?

A

Suprasellar GCT

139
Q

Microsurgical PISKA approach

A

Internal occipital vein, BVR, internal cerebral vein and superior vermian vein should be navigated.

140
Q

How do you manage a patient with a pineal region mass?

A

MRI whole neuroaxis with contrast (rule out drop mets)

Send serum and CSF markers (bHCG, AFP and PLAP)

ETV and biopsy if hydrocephalus

Stereotactic or endoscopic biopsy if no hydrocephalus

If germinoma then Radiotherapy. If a malignant GCT or pineoblastoma then radiotherapy and Chemotherapy

Surgical resection for mature teratomas OR GCTs that do not respond to oncological management.

141
Q

Which pineal region tumours should not be operated on?

A

Germinomas (as these are radio and chemosensitive)

Malignant tumours with evidence of metastasis (as surgery on the primary tumour does not confer a survival advantage)

142
Q

What are the approaches to the pineal region?

A

Supracerebellar infratentorial

Occipital transtentorial (recommended for lesions that can be accessed above the v. of Galen). Note, the tentorium is excised one cm lateral to the straight sinus.

Paramedian infratentorial supracerebellar keyhole (PISKA) performed in park-bench position

Transcallosal (for tumours extending into the CC and 3rd vent)

143
Q

What replaces the term PNET?

A

Embryonal tumours

144
Q

What are the features of wnt-activated medulloblastomas?

A

Arise from the middle cerebellar peduncle. 10% of cases.Mostly older children. Good prognosis with mets in 10% at diagnosis. Arise from progenitor cells in the lower rhombic lip.

145
Q

What are the features of SHH activated medulloblastomas?

A

All age groups. 30% of all cases. P53 mutant. Cerebellar hemisphere location. Arise from precursors of the external granule layer. Prognosis is good in infants but intermediate in others.

146
Q

Where do wnt-activated medulloblastomas arise?

A

From the middle cerebellar peduncle as they arise from precursor cells of the rhombic lip.

147
Q

What are the 4 genetic clusters of medulloblastoma?

What are the 4 histological clusters of medulloblastoma?

A

Wnt (10%), SSH (p53) (30%), Group 3 (20%) and Group 4 (40%)

Classic, Nodular aka desmoplastic, Extensive nodularity and Large cell aka anaplastic. Note large cell are always high risk. Classic are always standard risk except with SSH p53 mutation, which are high risk.

148
Q

What is suggested if a patient with a medulloblastoma presents with back pain, radiculopathy or urinary retention?

A

Drop mets

149
Q

What are the classical neurological findings in a patient with a posterior fossa mass?

A

Hydrocephalus

Papilloedema

Truncal / Limb ataxia

Nystagmus

Diplopia

150
Q

What is sugar coating in medulloblastoma?

A

Tumour infiltration causing thickening of the arachnoid

151
Q

Where do medulloblastomas arise from?

A

Roof of the 4th ventricle (note ependymomas arise from the floor!)

152
Q

What is an ETMR?

A

Embryonal tumour multilayered rosettes - C19MC amplification on Ch19.

These are extremely aggressive with median survival 6-9 months

153
Q

What does P53 mutation convey with SHH-activated medulloblastomas?

A

P53 mutation is a high-risk tumour. P53 WT is a low-risk tumour.

154
Q

What is the most prevalent type of medulloblastoma?

A

Group 4

155
Q

What is the treatment for medulloblastoma?

A

Maximal safe surgical resection

30% will require a VP shunt

156
Q

How do you risk stratify medulloblastomas post-op?

A

Standard = GTR no mets and CSF clear. SSH activated P53 WT or Group 3/4

Low = GTR WNT-activated

High risk = >1.5 cm3 residual, mets or CSF cells, SHH activated P53 and large cell histology

157
Q

What is the Chang classification for medulloblasoma?

A

A T1-4 M1-4 grading system from the preMRI era. The T is based on size < or > 3 cm and brainstem involvement. The M is based on CSF seeding.

Not used much now as based on old data

158
Q

What are ATRTs?

A

Atypical teratoid / rhabdoid tumours (WHO grade 4)

SMARCB4 mutation

An aggressive embryonal tumour with rhabdoid features. May be associated with primary rhabdoid tumours.

Radiologically look like medulloblastomas

159
Q

Which patients develop precious puberty with pineal region tumours?

A

BOYS only! The HCG stimulates testosterone production. The lack of raised FSH and LH means this is not converted to oestrogen in girls.

160
Q

Regarding pineal region tumour markers, what condition can cause a false positively raised AFP?

A

Liver disease!

161
Q

What is the treatment for germinoma?

A

Chemotherapy (cisplatin) +/- radiotherapy depending on CSF cytology + or if there are drop mets

162
Q

What is the differential of a pineal region tumour?

A

Germinomas, Non-germinomatous germ cell tumours (embryonal carcinomas, yolk sac tumours, choriocarcinomas, teratomas and mixed types), pineal tumours (pineoblastomas / pineocytomas), glial tumours, meningiomas, lymphomas, mets and infection.

163
Q

What are the features of germ cell tumours?

A

95% younger than 35 years. Male:female = 2:1, half of all germ cell tumours are germinomas. They engulf the pineal gland and are hyperintense to gray matter.

164
Q

What are the histological subtypes of germ cell tumours (mnemonic = GETMyCar)

A

Germinomas, Embryonal carcinomas, Tertatomas, Mixed tumours and Choriocarcinomas.

165
Q

What are the features of pineal tumours?

A

Genetically predisposed with Rb mutations (trilateral retinoblastomas), Male:female = 1:1 and more frequent in young adults.

166
Q

How can pineoblastomas and pineocytomas be distinguished?

A

Pineoblastomas are large (>3cm usually) with peripheral calcification resulting in obstructive hydrocephalus. Pineocytomas are enhancing well circumscribed lesions with calcification that rarely extend into the 3rd ventricle.

167
Q

Which gliomas arise in the pineal region?

A

Thalamic or tectal gliomas (usually low grade). Histologies include ependymoma, astrocytoma, oligodendroglioma and glioblastoma.

168
Q

What are the possible presentations of a patient with a pineal region tumour?

A

Raised ICP secondary to hydrocephalus, brainstem compression, Parinaud syndrome, 3rd nerve palsy endocrine disturbance (bHCG causing precocious puberty), hypothalamic dysfunction, cerebellar compression and pineal apoplexy.

169
Q

What is the significance of CSF tumour markers with germinomas?

A

AFP = yolk sac tumours, embryonal carcinomas and immature teratomas; bHCG (from syncytiotrophoblasts) = choriocarciomas, germinomas and embryonal cell carcinomas; pALP = Germinomas but may be positive in all types.

170
Q

What investigation should all patients with pineal region tumours have?

A

MRI whole spine to look for drop mets.

171
Q

What are the options for the treatment of hydrocephalus secondary to a pineal region tumour?

A

EVD, ETV or VP shunt;

172
Q

How can a histological diagnosis of a pineal region tumour be made?

A

CSF markers, stereotactic, endoscopic or open biopsy

173
Q

What are the pros and cons of performing a stereotactic biopsy for a pineal region tumour?

A

Ease of performance and low complication rate. Risk of non-diagnostic sample / misleading if mixed germ cell tumours and seeding (if pineoblastoma).

174
Q

What are the approaches for a stereotactic biopsy of a pineal region tumour?

A

1) Precoronal with low frontal entry point which runs inferior and lateral to the ICV and 2) Parieto-occipital (similar to shunt trajectory) for tumours with posterior / lateral extension.

175
Q

What are the pros and cons of performing an endoscopic biopsy?

A

Allows ETV and biopsy to be performed in the same procedure if the patient has hydrocephalus. Risks include may need a second burr hole or the use of a flexible endoscope, risk of IVH and loss of view and learning curve for use of endoscope.

176
Q

What are the pros and cons of performed an open biopsy?

A

Allows more tissue for histology, reduces the tumour burden, allows direct control of bleeding, may allow complete resection (which is curative for teratomas / pineocytomas). Risk of increased morbidity / mortality.

177
Q

What are the common open approaches to the pineal region?

A

Infratentorial supracerebellar, occipital transtentorial and interhemispheric transcallosal.

178
Q

What are the pros and cons of the infratentorial supracerebellar approach to the pineal gland?

A

Sitting or concorde position, extraaxial approach / corridor inferior to the deep veins and gravitational surgical retraction / CSF drainage; Risks of blood pooling, cerebellar retraction, awkward / uncommon surgical position, air embolism and venous sinus injury.

179
Q

What are the pros and cons of the occipital trans-tentorial approach to the pineal gland?

A

¾ prone or sitting position with oblique trajectory allows excellent exposure of the tectal plate and allows gravitational retraction; Risks of injury to the deep veins, occipital lobe retraction resulting in visual defect.

180
Q

What are the pros and cons of the transcallosal interhemispheric approach?

A

Prone or sitting position with callosotomy over the tumour and less than 2 cm. May be combined with the occipital transtentorial approach. Risk of injury to the deep veins, bridging veins limiting exposure and risk of disconnection syndrome.

181
Q

What are the adjuvant treatment measures for pineal tumours?

A

RTx of the neuroaxis is recommended for germinomas, malignant germ cell tumours, intermediate pineal cell tumours, anaplastic gliomas or cases of subtotal resection of pineocytomas or ependymomas.

182
Q

What is the treatment of germinomas?

A

In most centres reduced doses of craniospinal irradiation are given in combination with chemotherapy for germinomas, NG-GCTs, germinomas with syncytiotrophoblasts, recurrent or metastatic germinomas or pineal cell tumours.

183
Q

What are the chemotherapy regimens used for pineal region tumours?

A

The Einhorn regimen includes cisplatin, vinblastine, bleomycin (or etoposide to replace vinblastine / bleomycin reduces pulmonary toxicity).

184
Q

What is the role of radiosurgery for pineal region tumours?

A

It is useful for pineocytomas

185
Q

What is the prognosis of pineal region germinomas?

A

Germinoma outcome from Hardenberg et al in 36 patients treated with RT is 90% with 5 year disease free survival of 97%. Poor prognostic markers included positive CSF cytology and increased b-HCG.

186
Q

What is the prognosis of pineal region NGGCTs?

A

5 year survival with RT was 36%. There was 10% mortality from chemotherapy use.

187
Q

What is the prognosis of pineocytomas and pineoblastomas?

A

Total or subtotal resections of pineocytomas results in mean survival of 8 years and 24 months for pineoblastomas following gross total resection and RT.

188
Q

What is the difference between primary and secondary lymphoma?

A

Primary lymphoma starts in the CNS. Secondary lymphoma has metastatic spread of systemic lymphoma to the cerebral parenchyma. They are pathologically identical but primary tends to be more in the parenchyma and secondary has more leptomeningeal involvement.

189
Q

What are the specific types of primary CNS lymphoma?

A

Diffuse large B cell lymphoma (most common) Immunodeficiency-associated CNS lymphoma - AIDS related - EBV diffuse large B cell Intravascular large B-cell lymphoma Miscellaneous rare lymphomas in the CNS -low grade B-cell lymphomas -T-cell & NK/T-cell -anaplastic large cell Extranodal marginal zone lymphoma of ‘mucosa-associated lymphoid tissue’ (MALT lymphoma) of the dura

190
Q

What are the characteristic sites for lymphoma?

A

Corpus callosum Basal ganglia Periventricular Cerebellum if infratentorial

191
Q

What are the histological features of lymphoma?

A

Tumour cells form perivascular cuffs which demonstrate multiplication of basement membranes (best demonstrated with silver reticulum stain). Cells stain for B-cell (CD20) and T-cells (CD3).

192
Q

What does normal brain MR Spectroscopy show?

A

Hunter’s angle with choline

193
Q

What are the indications for operating on lymphoma?

A

Biopsy

194
Q

What does diffuse CD3 staining suggest?

A

T-cell lymphoma

195
Q

What does this MR Spectroscopy show?

A

High choline (Cr should be just next to it but not even visible!)

Low NAA

High lipid/lactate peak (which is higher than would be expected from a HGG)

Suggestive of lymphoma

196
Q

What is intravascular lymphoma?

A

Formerly known as angioendotheliomatosis , there is no solid mass and all the lymphoid B-cells are found within the lumen of small vessels. Present with multifocal strokes. Needs a brain biopsy!

197
Q

What are the specific types of primary CNS lymphoma?

A

Diffuse large B cell lymphoma (most common) Immunodeficiency-associated CNS lymphoma - AIDS related - EBV diffuse large B cell Intravascular large B-cell lymphoma Miscellaneous rare lymphomas in the CNS -low grade B-cell lymphomas -T-cell & NK/T-cell -anaplastic large cell Extranodal marginal zone lymphoma of ‘mucosa-associated lymphoid tissue’ (MALT lymphoma) of the dura

198
Q

What is the difference between primary and secondary lymphoma?

A

Primary lymphoma starts in the CNS. Secondary lymphoma has metastatic spread of systemic lymphoma to the cerebral parenchyma. They are pathologically identical but primary tends to be more in the parenchyma and secondary has more leptomeningeal involvement.

199
Q

What percentage of lymphoma patients have seizures?

A

30%

200
Q

How does lymphoma compare to glioma on MR spectroscopy?

A

Much higher choline to creatinine ratio in lymphoma Lipid peak also characteristic in lymphoma.

201
Q

What is unifocal langerhans cell histiocytosis?

A

AKA Eosinophilic granulomatosis / Histiocytosis X

Presents as a tender enlarging skull mass (Parietal>Frontal) in patients <20 years old

XR shows a non-sclerotic punched out lesion with sharply defined margins involving both the inner and outer table. No sunburst appearance so different from a haemangioma. If sclerotic margins think of an epidermoid

CT is helpful if you only have an XR

202
Q

How does lymphoma compare to glioma on MR spectroscopy?

A

Much higher choline to creatinine ratio in lymphoma Lipid peak also characteristic in lymphoma.

203
Q

In MR Spectroscopy, what peak is seen before Choline?

A

Myoinositol

204
Q

What percentage of lymphoma patients have seizures?

A

30%

205
Q

How does PCNSL present?

A

Mental status change (encephalopathy / dementia)

Raised ICP

Seizure

Cranial nerve palsies

206
Q

What conditions increase the risk of PCNSL?

A

Immunosuppression (AIDS/ Transplant)

EBV

Rheumatoid / SLE / Sjoergren’s

207
Q

How do you investigate a patient with suspected PCNSL?

A

HIV test / CD4 count

LP

Bone marrow biopsy

CT-CAP

MRI brain and spine with contrast

Testicular USS if >60 years

Opthalmology (for uveitis)

208
Q

What are the CT findings you would expect with PCNSL?

A

Hyperdense lesion on non-contrast imaging

Fluffy border

Surrounding oedema with mass effect

Homogenous contrast enhancement

209
Q

What blood test is an independent prognosticator for lymphoma?

A

LDH - indicates rapid cell turnover

210
Q

What is the sensitivity of LP for suspected PCNSL?

A

10-20% when >10ml is taken. Repeating up to 3 times increases yield. Requires flow cytometry to provide information on tissue typing.

211
Q

What are the histological findings in a craniopharyngioma?

A

Palisading epithelium, wet keratin and stellate reticulum associated with gliosis and rosenthal fibres.

Cystic and solid components with cholesterol laden fluid, necrosis and calcification

212
Q

What are the indications for surgery in PCNSL?

A

Biopsy

213
Q

How is PCNSL treated?

A

Whole-brain radiation

Chemotherapy (in non-AIDS cases) through IV and IT methotrexate

Rituximab (anti-CD20 monoclonal Ab)

214
Q

How are histiocytic tumours classified?

A

Histiocytes are mononuclear phagocytes (macrophages)

  1. Malignant (histiocytic lymphoma)
  2. Reactive (benign histiocytes)
  3. Langerhan’s histiocytosis (unifocal, multifocal unisystem, multifocal multisystem)
  4. Erdheim chester / Rosai-Dorfman
  5. Histiocytic sarcoma
215
Q

Describe a fronto-temporal approach for craniopharyngioma.

A

Pterional craniotomy

Prox. sylvian dissection

Identify ICA and Optic nerve - widely open the arachnoid and release CSF

View both optic nerves, chiasm, lamina terminalis and follow ICA back to the bifurcation and release arachnoid between ACA and optics.

Decompress cyst

Dissect margins and protect the stalk / hypothalamus between the optic nerves and/or between optico-carotid window by mobilising carotid downwards

Open lamina terminalis if 3rd ventricular component

216
Q

Anatomical view / reach of the pterional approach

A
217
Q

What are the operative windows for transcranial craniopharyngioma resection?

A

Prechiasmatic

Translamina terminalis

Optico-carotid

Carotid-oculomotor

218
Q

Anatomy of the opticocarotid window

A
219
Q

How do you treat LCH?

A

Curettage if unifocal

Multiple lesions that have extracalvarial bony involvement are treated with chemo/radiotherapy. Very radiosensitive.

220
Q

What is Hand-Schuller-Christian triad?

A

Associated with LCH: DI (pituitary invasion), Exopthalmos (intraorbital tumour) and lytic lesions of the cranium.

221
Q

What % of GCTs are synchronous i.e. in the pineal and sellar region?

A

13%

222
Q

What are the different types of GCTs?

A

Germinomas

Non-germinomas

Mixed

223
Q

What are teratomas?

A

GCTs composed of two or more germ cell layers (endo/meso/ectoderm)

Mature teratomas contain mature skin / bone etc

Immature teratomas contain fetal tissues

Malignant transformation to carcinoma or sarcoma.

224
Q

How should GCT tumour markers be used?

A

For monitoring response to treatment. Less useful for diagnosis and they may be mixed types. Note: if pALP is positive then no need for surgery and treat as a germinoma (chemotherapy and low dose RT with boost to the tumour).

225
Q

How would you manage a patient with a pineal lesion?

A

MRI brain and whole spine + contrast

Serum / CSF tumour markers (bHCG, AFP & pALP)

If hydrocephalus then ETV + biopsy

If germinoma then chemo/rad

All others resection

226
Q

What do craniopharyngiomas arise from?

A

Benign epithelial remnants of Rathke’s pouch and therefore arise from the anterior pituitary.

227
Q

Which mutations are associated with craniopharyngiomas?

A

Adamantinomatous = beta-catenin

Papillary = BRAF (usually solid)

228
Q

What are the age distributions of craniopharyngiomas?

A

Bimodal <15 years or >50 = adamantinomatous

40-50 years = papillary

229
Q

What is the blood supply to a craniopharyngioma?

A

Sup. hypophysial

ACA

ICA

PCom

230
Q

What are the operative approaches to craniopharyngiomas?

A

Endoscopic transphenoidal

Subfrontal / Fronto-temporal - approach is optico-carotid or subchiasmatic if the chiasm is pre-fixed and between the optic nerves (prechiasmatic) if post-fixed

Transcallosal or translamina terminalis for tumours limited to the 3rd ventricle

231
Q

What are the management options for craniopharyngioma?

A

Shunting if hydrocephalus

Cyst aspiration and ommaya reservoir insertion

Bleomycin to the cyst through the ommaya

Surgery of solid component

Radiotherapy / SRS to residual

232
Q

What are the age distributions of craniopharyngiomas?

A

Bimodal <15 years or >50 = adamantinomatous

40-50 years = papillary

233
Q

Which steroids should you prescribe post-op craniopharyngioma resection?

A

Both Dex for swelling and Hydrocortisone for the mineralocorticoid effect. Taper slowly post-op to avoid aseptic meningitis.

234
Q

What endocrinopathy is most common after craniopharyngioma resection?

A

DI and all are considered be Addisonian (hypoadrenal) so need steroids!

235
Q

What are the sequelae of bilateral hypothalamic injury?

A

Hyperthermia

Somnolence

Loss of third sensation due to damage to osmoreceptors

Hyperphagia

236
Q

What do all posterior pituitary and infundibular tumours express?

A

TTF-1 (Thyroid transcription factor-1)

237
Q

What are the most common primary tumour of the infundibulum?

A

Granular cell tumours (WHO grade 1)

238
Q

What is a pituicytoma?

A

A low grade glial cell tumour of the infundibulum (WHO grade 1)

239
Q

What is a spindle cell oncocytoma?

A

Non-neuroendocrine tumour of the pituitary gland occuring in adults

240
Q

What tumours primarily arise from the neurohypophysis / infundibulum?

A

Craniopharyngioma

Granular cell tumours

Pituicytomas

Spindle cell oncocytomas

241
Q

How would you investigate a patient with lymphoma?

A

HIV test/CD4 count CT CAP or whole body PET LP for cytology Bone marrow biopsy testicular US in males ophthalmological examination for uveitis and intraocular lymphoma

242
Q

What are the differences in imaging of lymphoma between AIDS -ve and +ve patients

A

AIDS +ve patients with lymphoma often multifocal and ring enhancing because of necrotic centre AIDS-ve lymphoma enhance homogeneously

243
Q

What are the indications for operating on lymphoma?

A

Biopsy

244
Q

Main chemotherapy agent used in treatment of lymphoma

A

Methotrexate

245
Q

Which mutations are associated with craniopharyngiomas?

A

Adamantinomatous = beta-catenin

Papillary = BRAF (usually solid)

246
Q

How would you manage a patient with a pineal lesion?

A

MRI brain and whole spine + contrast

Serum / CSF tumour markers (bHCG, AFP & pALP)

If hydrocephalus then ETV + biopsy

If germinoma then chemo/rad

All others resection

247
Q

How should GCT tumour markers be used?

A

For monitoring response to treatment. Less useful for diagnosis and they may be mixed types. Note: if pALP is positive then no need for surgery and treat as a germinoma (chemotherapy and low dose RT with boost to the tumour).

248
Q

Which GCTs have high pALP?

A

Germinomas - check the CSF and serum levels

249
Q

Which GCTs have high AFP?

A

Immature teratomas

Yolk sac tumours

Embryonal carcinomas

250
Q

Which GCTs are classically associated with raised bHCG?

A

Choriocarcinomas (also some germinomas)

251
Q

Which germinomas are b-HCG positive?

A

Syncytiotrophoblastic variant. b-HCG is positive in 10-50% of all germinomas. CSF values >50 mIU/ml are considered positive.

252
Q

What is the gender difference between GCTs?

A

In Males they occur most frequently in the pineal whilst in females, they are more common in the suprasellar region.

253
Q

What % of GCTs are synchronous i.e. in the pineal and sellar region?

A

13%

254
Q

Which LCHs present like meningiomas?

A

Rosai-Dorfman and Erdheim chester

255
Q

What are the indications for surgery in PCNSL?

A

Biopsy

256
Q

What is the sensitivity of LP for suspected PCNSL?

A

10-20% when >10ml is taken. Repeating up to 3 times increases yield. Requires flow cytometry to provide information on tissue typing.

257
Q

What blood test is an independent prognosticator for lymphoma?

A

LDH - indicates rapid cell turnover

258
Q

What are the CT findings you would expect with PCNSL?

A

Hyperdense lesion on non-contrast imaging

Fluffy border

Surrounding oedema with mass effect

Homogenous contrast enhancement

259
Q

How do you investigate a patient with suspected PCNSL?

A

HIV test / CD4 count

LP

Bone marrow biopsy

CT-CAP

MRI brain and spine with contrast

Testicular USS if >60 years

Opthalmology (for uveitis)

260
Q

What conditions increase the risk of PCNSL?

A

Immunosuppression (AIDS/ Transplant)

EBV

Rheumatoid / SLE / Sjoergren’s

261
Q

In paediatrics do low grade gliomas transform into higher grade tumours?

A

Very rarely as they do not harbour IDH1/2 mutations

262
Q

What is the initial management of low grade gliomas in children?

A

Maximal safe resection to gain a tissue diagnosis and reduced the tumour burden

263
Q

What is the 5 year progression free survival and overall survival for children with low grade gliomas?

A

69% and 95% respectively

264
Q

What are risk factors for progression in children with low grade gliomas?

A

Young age, incomplete resection, fibrillary histologic features and hypothalamic / chiasmatic location

265
Q

What are the options for recurrent or residual tumour LGG?

A
  1. Observation
  2. Radiotherapy in older children confers a 5 year progression free survival of 71% and overall survival 93%
  3. Adjuvent chemotherapy (agents include: vincristine, carboplatin, vinblastine, 6-thioguanine, procarbazine, lomustine, cisplatin, etoposide and irinotecan)
266
Q

Is radiotherapy more effective than chemotherapy?

A

No, similar event-free survival with multiagent chemotherapy and radiotherapy

267
Q

Is temozolomide effective for LGG in children?

A

A phase 2 trial in children with LGG showed it was ineffective

268
Q

Which pathway is important for cell replication that can be targeted with biological therapies?

A

MAPK (mitogen activated protein kinase)

269
Q

What is the most common BRAF inhibitor used?

A

Dabrafenib

270
Q

What are the most common MEK inhibitors used?

A

Trametinib and selumetinib

271
Q

What is the response to chemotherapy of LGG BRAF mut+ with deletion of CDKN2A?

A

Conventional chemotherapy has a poor response where as MEK inhibitors such as Selumetinib has shown durable responses

272
Q

What is the most common astrocytoma in children?

A

Pilocytic astrocytomas accounting for 20% of all brain tumours in children

273
Q

What are the most common locations for pilocytic astrocytomas?

A

Cerebellum

Suprasellar region

274
Q

What % of pilocytic astrocytomas have a poor outcome?

A

20% have local recurrence or dissemination

275
Q

What mutation is most commonly seen with pilocytic astrocytomas?

A

KIAA1549-BRAF fusion in 90% - most common in the posterior fossa and associated with an increased overall survival

276
Q

What proportion of brain tumours in children are high grade gliomas?

A

10%

277
Q

What is the survival of children with HGG?

A

70-90% die within 2 years of diagnosis despite surgery and adjucent therapy

278
Q

What is this lesion?

A

Suprasellar BRAF V600E mutated LGG

279
Q

What is this lesion?

A

A cystic and solid pilocytic astrocytoma in the right temporal lobe

280
Q

What is this lesion?

A

Diffuse midline gliomas with H3K27M mutation

281
Q

What is this lesion?

A

A large infiltrative slightly enhancing paediatric type HGG of the right hemisphere H3-wild type and IDH-wild type

282
Q

What is this lesion?

A

ZFTA fusion-positive supratentorial ependymoma

283
Q

What is this lesion?

A

A heterogeneously enhancing righ intratentorial posterior fossa A tumour compressing the brain stem (K3K27M negative which is a characteristic of PFA)

284
Q

What is this lesion?

A

An enhancing WNT-activated medulloblastoma in the right CP angle arising from the cerebellar peduncle

285
Q

What is the lesion?

A

A cerebellar convexity SHH-activated P53-wildtype medulloblastoma showing cystic and solid heterogeneous enhancement

286
Q

What is this lesion?

A

Group 4 (non-enhancing) medulloblastoma arising from the vermis

287
Q

When is the optimal time for surgery on a pineal region tumour with residual bulky disease (>2 cm)?

A

After chemotherapy as there may be a teratoma component

288
Q

What is the treatment for pineal region teratomas?

A

Surgical - as they are resistant to chemo- and radiotherapy

289
Q

What is growing teratoma syndrome?

A

Where a secretary NGGCT continues to grow after 3 cycles of chemotherapy as there is an immature teratoma component that is resistant. These should undergo surgery BEFORE radiotherapy!!

290
Q

What is the most common diagnosis of pituitary stalk thickening with central DI?

A

Langerhans cell histiocytosis

Germinoma

291
Q

How do you manage a patient with central DI and a bifocal lesion (pineal and floor of third ventricle?

A

Tumour markers - if negative go straight to chemotherapy, DOES not need a biopsy!

292
Q

What is the oncological management of a secretory NGGCT?

A

Chemotherapy + ventricular or craniospinal (if metastatic) RT

293
Q

What are the lab cut-offs for positive markers for pineal region tumours?

A

>25 AFP

>50 HCG

(check the local lab reference ranges!)

294
Q

What is the chemotherapy for germinoma?

A

Non-metastatic = Carbo-Etop then Etop-Fos Followed by RT

Metastatic = Straight to RT (no chemo!)

295
Q

What is PEI chemotherapy?

A

CisPlatin

Etoposide

Ifosfamide

Given to high-risk NGGCTs

296
Q

Which chemotherapy agent has recently been effective for pineal region tumours?

A

Vinblastine - has a better side effect profile

297
Q

What is the risk of a secondary neoplasm following craniospinal irradiation?

A

8% will have another tumour directly related to this in addition to an increase in the total number of co-morbidities throughout life

298
Q

What test is used to confirm the diagnosis of DI?

A

Water deprivation test

299
Q

What is the first hormone deficiency to develop after whole brain radiotherapy?

A

Growth hormone deficiency

FRCS Part 2 (17 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions