Neuro + H&N DDx Flashcards
1
Q
Haemorrhagic brain tumour DDx
A
Primary: Glioblastoma Metastases: melanoma, renal cell carcinoma, thyroid carcinoma and choriocarcinoma Less frequently haemorrhagic, but the most common malignancies: breast and lung
2
Q
Transcallosal mass
A
Glioblastoma (butterfly glioma) Lymphoma Demyelinating disease Metastases (rare)
3
Q
Neurofibromatosis 1 features
A
- FASI (focal areas of signal intensity) (60-85%): which involve the cerebellar white matter, globus pallidus, thalamus and brainstem; T1 isointense to white matter; T2 hyperintense and poorly defined, no mass effect; no enhancement; DWI increased ADC values; lesions tend to disappear by early 20s
- Plexiform neurofibromas: soft tissue infiltrating lobules along courses of peripheral nerves; hyperintense on T2/STIR, variable enhancement, classically central
- Optic pathway gliomas (15-20%): intraorbital optic nerve, chiasm/hypothalamus, optic tracts, rarely into radiations; fusiform enlargement +/- enlargement
- Skeletal
- Sphenoid wing dysplasia - almost always associated with orbital PNF
- Lambdoid defect - absence of bone along the lambdoid suture
- Pseudoarthroses of the long bones (tibial involvement is the most common
- Ribbon ribs
- Posterior vertebral scalloping
- Brainstem can show moderate to marked enlargement (hamartoma), probably secondary to vacuolation, less T1 hypointense and T2 hyperintense than brainstem glioma, resolves in teen/early adulthood
- Vascular dysplasia (moyamoya arteriopathy) (3-7%): vessel narrowing, especially distal internal carotid artery with collateral formation
4
Q
Astrocytoma vs Ependymoma
A
Astrocytoma
- Child
- More eccentric
- Bone remodelling less common
- Low T1 signal
- Infiltrative with ill-defined enhancement
- Syrinx is less common
- Haemorrhage is less common; less likely cystic and necrotic
Ependymoma
- Child or adult
- More concentric
- Bone remodelling is common
- Low T1 signal
- Well-defined enhancement
- Syrinx is more common
- Haemorrhage is more common, more likely cystic and necrotic
5
Q
Meningioma vs Hamangiopericytoma
A
Meningioma
- Hyperdense on CT
- Can have dural tail
- Homogenous avid enhancement
- Respects boundaries, associated with hyperosteosis
- 25% calcify
- Spoke-wheel vessel arrangement
Hamangiopericytoma
- Hyperdense on CT
- Can have dural tail
- Heterogenous on T1, T2, T1C+
- Can destroy bone
- No calcification
- Vascular with flow voids
6
Q
Neurofibromatosis 2 features
A
- Mnemonic: Multiple Inherited Schwannomas, Meningiomas, and Ependymomas (MISME)
- Schwannoma: intradural, extramedullary - occurs anywhere; tend to be multiple, with too many to count; bilateral acoustic is diagnostic of NF2
- Meningioma: intradural, extramedullary - typically the thoracic spine but can occur anywhere
- Ependymoma: intramedullary - typically upper cervical cord or conus but occurs anywhere
- Presents: 50% present with hearing loss, juvenile subcapsular lens opacities common; retinal and choroidal hamaratomas (10-20%); cafe au lait spots; minimal to no cutaneous neurofibromas; cutaneous schwannomas in 67%
7
Q
Von Hippel Lindau Syndrome features
A
- Diagnosis: two or more CNS HGBLs; or 1 HGBLs + visceral lesion or retinal haemorrhage
- Haemangioblastomas (60-80%) - arise from the pia
- Typically multiple, but consider VHL if present in a younger patient
- 40-50% in the posterior 1/2 of the spinal cord
- 44-72% cerebellum (posterior > anterior 1/2)
- 10-25% brain stem (posterior medulla)
- Ocular angiomas (25-60%) VHL gene carriers - causes retinal detachment, haemorrhage
- Endolymphatic sac tumours (ELSTs): large T-bone mass, located posterior to the internal auditory canal near the vestibular aqueduct
- T1 heterogenous hyper/hypointense; T2 hyperintense; FLAIR hyperintense; T1C+ heterogenous enhancement
- Clinical features: capillary HGBLs of the CNS and retina, ELSTs, renal cysts, clear cell RCC, pancreatic cysts, islet cell tumours pheochromocytoma, epidydimal cysts, cystadenomas.
8
Q
Tuberous Sclerosis features
A
- Hamartomas of multiple organs –> CNS, skin, kidneys bone
- Tubers: 90% cerebral > cerebellum 24-36%; often associated with radial migration lines extending towards the lateral ventricles; CT low attenuation, with gyral expansion, may have some enhancement; T1 hyperintense in the very young prior to myelination, becoming hypointense after myelination; T2 isointense in the very young prior to myelination, becoming hyperintense post myelination; FLAIR hyperintense; occasional calcification; 3-4% of the cortical tubers enhance, whereas 33-92% of the cerebellar tubers enhance
- Subependymal nodules (SENs): follows anatomical distribution of the foetal germinal matrix: caudothalamic groove > body/atrium/temporal horn; irregular and elongated “candle drippings”, most calcify and most enhance; T1 slightly hyperintense, enhance
- Subependymal giant cell astrocytoma (SEGA): enlarging nodule at the foramen of Monro; irregular and diffuse enhancement; MRS decreased NAA and increased choline; WHO grade 1; can cause obstructive hydrocephalus
- Other lesions
- Cerebral aneurysms and dolichoectasia
- Retinal haemartoma (giant optic drusen)
- Renal angiomyolipoma (40-80%)
- Lymphangioleiomatosis
- Cardiac rhabdomyoma: present at birth, typically resolves spontaneously
- Sclerotic bone islands and cysts
9
Q
Diagnostic criteria for NF1
A
Diagnostic criteria – 2 or more required (CAFÉ SPOT):
- C: > 6 Café au Lait spots visible in a year
- A: axillary or inguinal freckling (not part of dx criteria)
- F: fibromas - 2+ neurofibromas or 1+ plexiform neurofibromas
- E: eye hamartomas 2+ iris hamartomas (Lisch nodules)
- S: skeletal abnormities - distinctive osseous lesion (eg: sphenoid wing dysplasia, or thinning of the long bone cortex with or without pseudoarthrosis)
- P: primary relative with NF1
- OT: optic tumour - optic nerve glioma
10
Q
NF1 Pathology
A
- 50% autosomal dominant and 50% de novo; variable expression but 100% penetrance
- Inactivation of neurofibromin at the NF gene locus on the long arm of chromosome 17 –> RAS GTPase-activating protein responsible for tumour suppression
- Associated with pheochromocytomas and malignancy peripheral nerve sheath tumours (MPNST)
11
Q
Diagnostic criteria for NF2
A
Definitive
- Bilateral CNVIII (vestibular schwannomas)
- 1st degree relatively with NF2 + either unilateral early onset vestibular schwannoma or any 2 of meningioma, glioma, schwannoma, or juvenile posterior subcapsular lenticular opacity
Presumptive
- Early-onset unilateral CNVIII schwannoma (age < 30) + one of the following: meningioma, glioma, schwannoma,juvenile posterior subcapsular lenticular opacity
- Multiple meningiomas (>2) and unilateral vestibular schwannoma or one of the following: glioma, schwannoma, juvenile posterior subcapsular lenticular opacity
12
Q
NF2 Pathology
A
AD; chromosome 22 deletion with eventual inactivation of merlin (schwannomin) functionality
13
Q
VHL diagnostic criteria
A
Diagnosis: two or more CNS HGBLs; or 1 HGBLs + visceral lesion or retinal haemorrhage
14
Q
VHL pathology
A
- AD high penetrance (97%), variable expression; 20% due to new mutation
- Germline mutation of the VHL tumour suppressor gene on chromosome 3p25-26 –> inactivation of pVHL results in overexpression of hypoxia-inducible mRNAs, including VEGF –> involved in cell cycle regulation and angiogenesis
- Rate of new tumour development is not constant, varies with age (peak at 30-34 yo); average new lesion every two years
15
Q
Tuberous sclerosis diagnostic criteria
A
Diagnostic criteria: 2 major (definite) or 1 major + 1 minor (probable
- Major: Tuber, SEN, SEGA, cardiac rhabdomyoma, RAM, LAM, adenoma sebaceum, sub-/periungual fibroma, hypomelanotic macules, shagreen patch, retinal hamartoma
- Minor: White matter lesions, dental pits, gingival fibromas, rectal polyps, bone cysts, nonrenal hamartoma, retinal achromic patch, confetti skin lesions, multiple renal cysts
