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Flashcards in PNS/Familial/Other Tumors Deck (20):
1

Schwannomas

Definition
Epidemiology
Locations and associated symptoms
Imaging

Benign tumor composed of Schwann cells

Epidemiology - Most common 4th to 6th decades

Involve peipheral nerves
Usually in head and neck and flexor surfaces of extremities
Asymptomatic masses
Spinal tumors – radicular pain

Intracranial tumors – Cerebellopontine angle and attached to 8th nerve
Symptoms of hearing loss, tinnitus, facial numbness

Imaging: Scans show well-defined contrast enhancing mass

A image thumb
2

What is this?
What does the microscopy look like?

Q image thumb

Vestibulocochlear Schwannomas

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3

Neurofibroma

Definition
Association
Forms

Benign tumor composed of Schwann cells, fibroblasts, and perineural cells

Associated with NF type 1

Cutaneous (localized) neurofibroma: Most common
In dermis or subdermal
Usually solitary (not associated with NF1)

Peripheral nerve
Solitary
Plexiform – usually in NF1

4

What is the pathology of neurofibroma?

Hypocellular, elongated spindle cells with wavy nuclei
Diffusely infiltrate adjacent nerve & soft tissue

5

What is a plexiform neurofibroma?
What does it affect?
What is the malignant potential?

Transformation of multiple fascicles of nerves into NFoma, with preservation of anatomic configuration (Exclusively NF1)
Typically affect larger nerves or a plexus
High likelihood of malignant transformation

6

Where do malignant schwannomas affect?
What are they associated with?
What is the pathology?

Mostly extremites
CNS, associated with trigeminal nerve

Strong assoc. with NF1

Pathology
High grade, aggressive
Infiltrative, non-encapsulated felshy masses
Highly cellular, moderate to marked nuclear pleomorphism
High mitotic rate

7

NF1 - von Recklinghausen disease

Genetics
Epidemiology
Criteria
 

Genetics – AD
Almost complete penetrance
50% are new mutations
Neurofibromin - NF1 gene on Chromosome 17
GPCR dependent signal transduction pathway (tumor suppressor gene)
Abundant in Schwann cells and neurons

Epidemiology: 1/3000
Much more common than NF2

Criteria

Neurofibromas
Café-au-lait spots
Lisch nodules – Pigmentd hamartomas in iris
Optic glioma
Osseous lesions
Axillary freckling
Family history

8

What tumors are associated with NF1?

Neurofibromas (all types)
Most important are those that undergo transformation to malignant peripheral nerve sheath tumors
Optic nerve gliomas, other astrocytomas
Others – Rhabdomyosarcomas, pheochromocytomas, carcinoid tumors

9

NF2

Genetics
Epidemiology
Criteria

Genetics - AD
50% sporadic
Merlin product – Chr. 22
Tumor suppressor which promotes assembly of cell junctions
Loss of gene ruins cell-to-cell contact

Epidemiology: 1/40,000-50,000

Criteria
Bilateral vestibular schwannomas (most common manifestation)
Other associated tumors (meningiomas, schwannomas, gliomas, neurofibromas)
No plexiform NFoma and malignant transformation is rare

10

von Hippel Landau

Genetics
Epidemiology
Features

Genetics – AD
VHL gene – Chromosome 3
Controls angiogenesis through regulation of expression of EGF, EPO, and other GFs

Epidemiology
1/30,000-40,000

Features
Hemangioblastomas of CNS & retina: Cerebellar hemangioblastomas (25% in VHL, 75% sporadic)
Renal cell carcinoma
Pheochromacytoma
Pancreas, liver, kidney cysts
Retinal angiomas

11

Tuberous Sclerosis

Genetics
Epidemiology
Clinical S/S

Genetics: AD
Positive family history in 50%
TS caused by mutations in 2 tumor suppressor genes
TSC1 (Chr. 9) – Codes protein hamartin
TSC2 (Chr. 16) – Codes protein tuberin

Dimerize to regulate protein synthesis, cell proliferation (inhibit mTOR)

Epidemiology: 1 in 6000

Clinical S/S: Seizures, autism, cognitive dysfunction

12

Pathologic changes of tuberous sclerosis

Cortical hamartomas (tubers)
Neurons haphazardly arranged in cortex
Often have glial as well as neuronal features

Subependymal nodules – Tuber-like

Subcortical glioneuronal hamartomas

Subependymal giant cell astrocytomas
Large pleomorphic multinucleated tumor cells with eosinophilic cytoplasm
Astrocytic/glioneuronal origin
No malignant transformation or local invasion

Other – cutaneous angiofibromas, subungual fibromas, cardiac rhabdomyomas, renal angiomyolipomas, retinal hamartomas, etc.

13

Hemangioblastoma

Location
S/S
Imaging
Treatment
Cellular origin
Pathology

Most commonly cerebellar

Can be cerebral or spinal

S/S: Secondary to increased ICP due to obstruction

Imaging: MRI shows well defined contrast enhancing cystic mass with mural nodule (right)

Tx: Surgical resection
Grade 1 have rare reports of recurrence

Cellular origin unknown

Pathology: Numerous vessels, interspersed with stromal cells; abundant foamy (lipid) cytoplasm
 

14

Definition paraneoplastic syndromes

Syndrome produced by remote effect of a systemic malignancy that cannot be attributed to direct invasion by tumor or its metastasis, infection, ischemia, related metabolic/nutritional disorders, or toxic effects of therapy

15

Who is at risk for neurologic paraneoplastic syndromes?

0.1% of all cancer patients, 3% of Small Cell Lung Cancer patients (SCLC)
Strong female predominance

16

What is subacute cerebellar ataxia?
What cancers are associated with it?
What causes the disease?

Progressive ataxia, dysarthria, nystagmus, vertigo, diplopia, titubation
Ovarian cancer (80%) or breast cancer (10%)
Purkinje cell antibodies (PCA-1 or anti-Yo)

17

What are the S/S of Lambert-Eaton myasthenic syndrome?
What is the pathogenesis?
What is it associated with?

S/S: Muscle weakness (legs), improves with testing on exam
Extraocular sparing

Ab to P/Q-type voltage-gated Ca2+ channels
Decreased ACh release

SCLC associated

18

What are the other most common paraneoplastic syndromes?

Limbic encephalitis
Encephalomyelitis
Opsoclonus myoclonus
Subacute sensory neuronopathy

19

What is the presentation of paraneoplastic syndrome?

Subacute worsening over weeks to months

May be presenting symptom of underlying malignancy
Initial cancer screening may be negative
Malignancy at limited stage due to effective anti-tumor immune response
More favorable oncological outcome

20

What is the pathogenesis for paraneoplastic syndromes?

Hypothesized that some visceral cancers express certain neural antigens
Immune response to antigens
Antibodies identified in some paraneoplastic syndromes
Induced against tumor cell antigens
Cross-react with neuronal cell antigens