extra-axial tumors

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#3. Recognize specific syndromes; extra-axial (cerebellopontine, pituitary, frontal) and intra- axial in brain tumor presentation

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#3. Recognize specific syndromes; extra-axial (cerebellopontine, pituitary, frontal) and intra-axial in brain tumor presentation. Extra-axial Tumors. Extrinsic to the brain - PowerPoint PPT Presentation

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Page 1: Extra-axial Tumors

#3. Recognize specific syndromes; extra-axial (cerebellopontine, pituitary, frontal) and intra-axial in brain tumor presentation

Page 2: Extra-axial Tumors

Extra-axial Tumors

• Extrinsic to the brain• include meningiomas, schwannomas,

neurofibromas, and pituitary tumors, craniopharyngiomas as well as mesenchymal tumors of the skull, spine, and dura mater

Page 3: Extra-axial Tumors

Meningioma

• Derived from arachnoid cap cells of the arachnoid mater

• Appear to arise from the dura mater grossly and on MRI: “dural based tumors”

• Most common intracranial locations: along the falx cerebri , the convexities and the sphenoid wing.

• Less common locations: foramen magnum, olfactory groove, and inside the lateral ventricle

Page 4: Extra-axial Tumors

Meningioma

• Mostly slow growing, encapsulated, and benign

• Malignant may invade adjacent bone or into the cortex

• Previous cranial irradiation: risk• Tx: Total resection, post op radiation (atypical

and malignant melanoma)

Page 5: Extra-axial Tumors

Postcontrast T1-weighted coronal MRI demonstrating a brightly enhancing lesion arising from the falx cerebri with moderate edema and mass effect on the right lateral ventricle. This is a falcine meningioma. Note also the small separate meningioma arising from the dura over the cerebral convexity.

Page 6: Extra-axial Tumors

Vestibular Schwannoma (Acoustic Neuroma)

• Arise from the superior half of the vestibular portion of the vestibulocochlear nerve (CN VIII)

• commonly present with progressive hearing loss, tinnitus, or balance difficulty

• Large tumors may cause brain stem compression and obstructive hydrocephalus

• Bilateral acoustic neuromas are pathognomonic for neurofibromatosis type 2, a syndrome resulting from chromosome 22 mutation.

Page 7: Extra-axial Tumors

Vestibular Schwannoma (Acoustic Neuroma)

• Tx: microsurgical resection or with conformal stereotactic radiosurgery (gamma knife or linear accelerator technology)

• Complication: damage to the facial nerve (cranial nerve VII)

Page 8: Extra-axial Tumors

A. Postcontrast T1-weighted axial MRI demonstrating a brightly enhancing mass on the right vestibular nerve with an enhancing tail going into the internal auditory canal (arrowhead). Pathology demonstrated vestibular schwannoma

Page 9: Extra-axial Tumors

Pituitary Adenoma• arise from the anterior pituitary gland (the

adenohypophysis). • Microadenoma: <1cm; Macroadenoma >1 cm• Functional (i.e., secrete endocrinologically active

compounds at pathologic levels) or nonfunctional (i.e., secrete nothing or inactive compounds).

• The most common endocrine syndromes are Cushing's disease due to adrenocorticotropic hormone (ACTH) secretion, Forbes-Albright syndrome due to prolactin secretion, and acromegaly due to growth hormone secretion.

Page 10: Extra-axial Tumors

Pituitary Adenoma

• Nonfunctional tumors commonly present when larger due to mass effect.

• Common symptoms : visual field deficits due to compression of the optic chiasm, or panhypopituitarism due to compression of the gland.

• Tx: Surgery (Transphenoidal), medical (Prolactinomas)

Page 11: Extra-axial Tumors

Postcontrast T1-weighted sagittal MRI demonstrating a large sellar/suprasellar lesion involving the third ventricle superiorly, and abutting the midbrain and pons posteriorly. The patient presented with progressive visual field and acuity loss. Pathology and lab work revealed a nonfunctioning pituitary adenoma.

Page 12: Extra-axial Tumors

Hemangioblastoma

• occur almost exclusively in the posterior fossa.• Twenty percent occur in patients with von

Hippel-Lindau (VHL) disease, a multisystem neoplastic disorder

• Appears as cystic tumors with an enhancing tumor on the cyst wall known as the mural nodule.

• Surgical resection is curative for sporadic (non-VHL associated) tumors.

Page 13: Extra-axial Tumors

Craniopharyngioma

• Benign cystic lesions that occur most frequently in children.

• Second peak of occurrence around 50 years of age.• Symptoms result from compression of adjacent

structures, especially the optic chiasm, pituitary or hypothalamic dysfunction or hydrocephalus may develop.

• Treatment is primarily surgical• Complications: Visual loss, pituitary endocrine

hypofunction, diabetes insipidus, and cognitive impairment from basal frontal injury

Page 14: Extra-axial Tumors

Neurofibroma• more fusiform and grow within the parent nerve,

rather than forming an encapsulated mass off the nerve, as with schwannomas.

• They are benign but not encapsulated.• They present similarly to schwannomas and the

two may be difficult to differentiate on imaging. • Patients with multiple neurofibromas likely have

neurofibromatosis type 1, also known as von Recklinghausen's neurofibromatosis.

• Resection for symptomatic lesions should be offered.

Page 15: Extra-axial Tumors

Intra-axial Tumors

• Intrinsic to the brain

Page 16: Extra-axial Tumors

• ASTROCYTOMA:- MOST COMMON PRIMARY INTRA-AXIAL

BRAIN TUMOR (low & high grade) - INVOLVE ALL LOBES WITH PREFERENTIAL TO FRONTAL & TEMPORAL LOBES

- GRADING BASED ON HISTOLOGY: hypercellularity pleomorphism vascular proliferation necrosis - DIAGNOSIS: CT, MRI, Angiography

- TREATMENT: Surgery, Radiation, Chemotheraphy or Combination

G L I O M A

Page 17: Extra-axial Tumors

Pilocytic Astrocytoma

Grade I

Low Grade Astrocytoma

Grade II

Anaplastic Astrocytoma

Grade III

Glioblastoma Multiforme

Grade IV

Median Age 13 years 35-45 years 46 years 50-60 years

Incidence 2% of gliomas 5%-25% of gliomas

10%-30% of gliomas

45%-50% of gliomas

Location Cerebellum, Brain stem, Optic nerve, Cerebral hemisphere

Cerebral hemispheres (frontal 40%), pons thalamus, midbrain

Cerebral hemispheres, thalamus, midbrain, pons

Any region particularly cerebral hemispheres (frontal 40%)

Presentation Depending on site, inc. ICP, seizures, motor deficit

Seizures(65%), Incr.ICP, Mental status change, motor deficit

Seizures(50%), Incr.ICP,

Mental status change, motor deficit

Increased ICP, mental changes, motor deficit, seizures

Treatment Surgical resection

Surgical resection

Sx resection, radiaion, chemoRx

Sx resection, radiaion, chemoRx

Outcome

5 year survival

100% 26%-33% 18% 5.5%

ASTROCYTOMA

Page 18: Extra-axial Tumors

OLIGODENDROGLIOMA

Incidence 2-10%

Age of predilection 30-55 yrs

Gender distribution Slightly more men (3:2)

Location Frontal, temporal, parietal often towards the midline

Cardinal clinical symptoms Seizures (50%-80%)

CT native Image as for astrocytma II or III, calcifications in about 50% of the cases, occasionally cysts, “fried egg” cytoplasm

CT after contrast medium Enhancement of Grade III tumors only; variegated picture, slight edema

Treatment: vary from conservative treatment of some patients with serial imaging studies and no intervention to aggressive multimodal treatment including surgical resection, radiotherapy, and chemotherapy

Page 19: Extra-axial Tumors

EPENDYMOMA

(10%)

• glial tumors that arise from ependymal cells within the central nervous system

Incidence 1-4%

Age of predilection 0-20 yrs

Gender distribution Predominantly men

Location Fourth and third ventricles, lateral ventricles, in childhood frontal, superficial frontier

Cardinal clinical symptoms Signs of intracranial pressure increase

CT native Slightly increased density; calcification possible

CT after contrast medium Slightly enhancement in solid tumor parts; grades III and IV similar to glioblastoma image

Page 20: Extra-axial Tumors

E P E N D Y M O M A

KEY FEATURES:-USUALLY OCCUR IN THE FLOOR OF THE 4TH VENTRICLE-POTENTIAL FOR SEEDING THRU THE NEURAXIS-WORSE PROGNOSIS THE YOUNGER THE PATIENT; 5 YRS SURVIVAL AT 80% FOR ADULTS & 20%-30% IN PEDIATRIC GROUP-MAXIMAL RESECTION FOLLOWED BY XRT