Tumor of Nervous System

Intrinsic vs extrinsic tumor

Intrinsic = from the brain tissue

Extrinsic = from other source

Intrinsic brain tumors

Glioma = astrocytoma, oligodendroglioma; ependymoma, PCNSL, medulloblastoma, pineal gland tumor

Astrocytoma subtypes

grade I (pilocytic astrocytoma, subependymal giant cell astrocytoma)

grade II (astrocytoma)

grade III (anaplastic astrocytoma)

grade IV (glioblastoma)

low grade = I-II; high = III-IV

What is pilocytic astrocytoma

Tumor of CHILDHOOD (most common); cerebellum > optic nerves > brainstem; caused by BRAF mutation

What is this

Cystic lesion with enhancing mural nodule → Pilocytic astrocytoma

Describe this

Atatypical piloid glial cells (long glia), focal hemosiderin deposit, Rosenthal fibers (dark pink fibers) → Pilocytic astrocytoma

What is this

NON enhance tumor with increased T2/FLAIR signal → Grade II Astrocytoma; causes seizure in young adult

What is glioblastoma

Most common malignant primary tumor; 60-70 y/o Pt with headache, seizure + focal neuro deficit

What is this

Ring enhancing lesion with central necrosis + edema, increased T2/FLAIR → glioblastoma

What is this

Butterfly tumor that CROSSES corpus callosum → Glioblastoma

Describe this

Hyperchromatic elongated astrocytes + irregular nuclear membrane; pseudopallisading necrosis surrounding central necrosis → Glioblastoma

What is Oligodendroglioma

15-20% of glioma which can either be grade II Oligodendroglioma or anaplastic Oligodendroglioma (AO) grade III

Describe this

Fried egg appearance + reticular blood vss growth → Oligodendroglioma

What is this

Non enhancing + calcification → Oligodendroglioma (better prognosis than pure astrocytic tumor)

What is ependymoma

From ependymal cell on ventricular surface; 5% childhood tumor from 4th vent in posterior fossa

What is this

Chronic supratentorial hydrocephalus from mass at floor of 4th vent → ependymoma

Describe this

The area surrounding vss = pseudorosettes → ependymoma

What is PCNSL

<3% primary brain tumor; common in immunocompromised Pt, EBV either earlier onset (31) compared to immunocompetent (60+)

PCNSL presentations

Subacute/chronic meningitis → CN and spinal nerve dysfunction → CSF and flow cytometry needed to confirm diag + stereotactic biopsy for histology

What is this

Periventricular lesion that CROSSES corpus callosum → PCNSL

Cancers that cross the corpus

Glioblastoma and PCNSL ONLY

Describe this

Diffuse infiltrate packed with mononuclear cell with scant cytoplasm

What is medulloblastoma

Most common malignant childhood tumor of periventricular → present with headache, ataxia, brainstem involvement signs

What is the difference between the left and right images

Lt lesion is in the ROOF of 4th vent; Rt lesion is in the FLOOR of 4th vent

Roof = medulloblastoma, floor = ependymoma

What are the differences between these three images on T2

Lt most has HYPERintense → pilocytic astrocytoma

The middle and rt is HETEROGENOUS enhancement → medulloblastoma and ependymoma that CANNOT be diff from this view

Describe this

Tumor cells around a central area (not lumen, canal or vss) filled with neurofibrillary process → TRUE rosette → medulloblastoma

What is Parinaud syndrome

Sign of pineal gland tumor → Signs of upward gaze palsy, convergence retraction nystagmus, light-near dissociation, and bilateral lid retraction.

What is this

Pineal gland tumor

Extrinsic benign tumors

Meningioma, Schwannoma, craniopharyngioma, hemangioblastoma

What is meningioma

35% of malignant primary brain tumor; Women and NF2 more common, found in dura mater commonly near cerebral convex (next to sagittal sinus) → present with headache, seizure + focal neuro deficit

What is this

In the DURA → Can tell because there is periarachnoid space between tumor and brain, dural tail present

Describe this

A points to whorl formation, B is psammoma bodies, C is nuclear pseudoinclusion → Meningioma features

What is Scwannoma

Tumor of cells that myelinate PERIPHERAL nerves (not CN I, II); most common are vestibular and acoustic neuroma (CN VIII) = hearing loss, tinnitus

What is this

Dense enhancement in internal auditory canal → Schwannoma

Describe this

The elongated TRUE pallisading nuceli = Antoni A and B with fibers between each pallisade = Verocay → sign of Schwannoma

Describe this

Pallisade = Antoni → Lt = A = packed pallisade; Rt = B = loose pallisade

What is craniopharyngioma

Benign tumor from Rathke remnant → suprasellar, partial calcification, solid → present with headache, visual impairment, impaired growth in children + hypopituitary in adult

What is this

Craniopharyngioma

What is hemiangioblastoma

Benign, slow growing tumor with many vss found in cerebellum, brainstem, spinal cord; associated with VHL when found with retinal fibroma

What is this

Enhanced mural module → can present in many ways → Hemangioblastoma

Describe this

Many vss + vacuolated stromal cell → hemangioblastoma

Common tumors that spread to brain

Lung, breast, melanoma is most common

What is leptomeningeal metastasis

Leukemia into subarachnoid space → BYPASS BBB

leptomeningeal metastasis presentation

Lumbar and cervical radiculopathies

Cranial neuropathies

Seizures

Confusion

Encephalopathy from hydrocephalus or raised intracranial pressure can be present

Note that weakness is atypical unless brain invasion is present.

What is this

Yellow arrow = visible CN V, VI, VII → do lumbar puncture

Brain metastasis management

Radiation, surgery, chemo

Leptomeningeal metastasis management

PALLIATIVE care; RT if there is nerve involvement, chemo for other malignancy