Optic nerve tumors ppt

OPTIC NERVETUMORS

Moderator: Dr. S.C. Bubanale

Presenter: Dr. Arushi Prakash

1Department of Ophthalmology, JNMC

29th October ’14

Contents

# Optic Nerve AnatomyTumors of the Optic Nerve# Optic nerve Gliomas

# Primary Optic Nerve Sheath Meningioma# Secondary Optic Nerve Sheath Meningioma# Optic Nerve Melanocytoma# Malignant Astrocytoma# Astrocytic Hamartoma# Lymphoreticular Tumors# Metastatic Tumors

Wednesday, October 29, 2014


Optic nerve :

The optic nerve being a portion of central nervous system is a tract, and not really a nerve. However, as a convention the 1.2 million axons that derive from the retinal ganglion cellscarry the name optic nerve,

until they partially decussate at the optic chiasm.

Wednesday, October 29, 2014 Department of Ophthalmology, JNMC 3

• Optic nerve is about 50 mm long and extends from the eye to optic chiasm.

• it carries about 1.2 million axons that derive from the retinal ganglion cells.

• It consists of 4 portions :

A)intraocular portion: optic disc- 1 mm in anteroposterior direction.

B) intra orbital portion : about 25 mm long.

C) intra canalicular portion with in the optic canal : about 9mm long.

D)intracranial portion : about 16mm long.


Constituent elements of optic nerve :

• Myelinated axons retinal ganglion cells.

• Oligidendrocytes : These are specialized glial cells that provide membranes for axonal myelination.

• Microglia : These immunocompetant cells play a role in protection of optic nerve from infection and also suggested that these cells probably play a role in apoptosis of retinal ganglion cells.


Astrocytes:-Astrocytes have extensive neurofibrillary processes that spread among nerve fibres. They form a part of blood brain barrier, and play a role in the nutritional

and structural support of axons.

-when axons are lost because of optic atrophy , astrocytes move and proliferate to fill the empty

spaces.


OPTIC NERVE TUMORS• Optic nerve is actually a tract of central

nervous system,so primary tumors of the optic nerve are more similar histopathologically to brain tumors than to peripheral nerve tumors.



Optic Nerve Glioma

• Pilocytic hamartomas of the anterior visual pathways.

• More posterior gliomas are generally more aggressive variants.

• Comprise ∼1% of all intracranial tumors

• About half are confined to the orbit; the remainder have intracranial extension

• manifest themselves early most commonly in the first decade of life (70% detected during the first decade, 90% by second)

• no definite sex predilection


• Roughly 29% of optic gliomas are associated with NF1

• Among patients with NF1, optic gliomas have been estimated to occur in 14.7-17.4%

• Isolated (without association to NF1) optic nerve gliomas are usually unilateral

• Bilateral involvement is believed to be pathognomonic of NF1



Enucleation

specimen with

optic nerve

glioma from a

patient with NF1.

Pathogenesis

• The NF1 gene product, neurofibromin, has a GTPase-activating protein domain that interacts with the Rasprotein, which is crucial in regulating signal transduction and cell proliferation and differentiation.

• Patients with NF1 are at high risk for developing a number of different types of tumors because of this.

• At this point, the exact mechanism of action of development of these tumors is unknown.



• The most common presenting findings are

• proptosis (94%).

• visual loss (87.5%).

• optic disc pallor (59%).disc edema (35%).

• and strabismus (27%).

• Patients infrequently present with asymptomaticisolated optic atrophy.

• An RAPD is usually present in unilateral or asymmetric cases

Clinical Features

• typical optic nerve- related visual field defect (if the patient is cooperative enough for visual field testing).

• Retinochoroidal collaterals may be present on the affected disc

• Central retinal vein occlusion or venous stasis retinopathy may occur.

• Large tumors may cause obstructive hydrocephalus with elevated ICP, headache, and papilledema.



Face photo of a 5-year-old girl who developed noticeable

proptosis OD and found to harbor an optic nerve glioma.

(a) The right fundus of a 5-year-old girl with a right optic nerve glioma reveals an optic nerve

with mild edema. Her visual acuity was moderately to severely reduced. (b) The left nerve was

normal.

• In rare cases, the optic glioma can resolve spontaneously

• Survival is typically reduced when hydrocephalus is present.


Diagnosis is confirmed by neuroradiologic findings

• Fusiform or globular enlargement of the optic nerve

• Thickening of both nerve and sheath by tumor

• Kinking or buckling of the optic nerve

• Regions of low intensity within the nerve (cystic spaces)

• Smooth sheath margins (no extradural extension)

• No calcification or hyperostosis on CT scan

• Isointense or mildly hypointense to brain on T1 -weighted MRI scan

• Hyperintense on T2-weighted MRI scan


biopsy of the mass is generally not required :

advent of high -resolution neuroimaging has raised diagnostic accuracy

biopsy of sheath alone may be inaccurate with reactive meningeal hyperplasia in gliomas falsely suggesting meningioma

biopsy of the optic nerve substance may produce additional visual loss

the histopathologic appearance of the tumor is not necessarily predictive of biological behavior


Pathology

• When confined to the orbital portion of the optic nerve, a glioma often appears as a fusiform swelling

• Histologically, an optic nerve glioma is generally characterized as a juvenile pilocytic astrocytoma, characterized by cells with prominent eosinophilicprocesses called Rosenthal's fibers. Mixed gliomasand oligodendrogliomas have been reported as well.

• The tumor may infiltrate the normal optic nerve substance or be confined primarily to the subarachnoid space.


Department of Ophthalmology, JNMC 21

The tumour cells in optic nerve

glioma have elongated or hair-

like

appearance (pilocystic).Hence

the name pilocystic

astrocytoma.

Rosenthal fibres in optic nerve

glioma. These are degenerative

eosinophilic substances found within

the cytoplasm of astrocytes.

There are characteristic but not

diagnostic of optic nerve glioma

• The latter type is more commonly found in patients with neurofibromatosis type 1.

• Rarely, there is exophytic extension of intracranial optic-chiasmal gliomas.

• The overall histologic appearance is Benign, with a

paucity of cellular atypia, mitosis, or tumor necrosis. Often, microcystoid extracellular spaces containing acid mucopolysaccharide produced by astrocytes are encountered. Such spaces may constitute a major portion of the optic nerve mass.


Natural history• Variable

• patients with the diagnosis of NF1 tend to fare better with respect to growth and visual prognosis.

• Most tumors grow slowly or have self-limited growth.

• some tumors are more aggressive, resulting in a rapid increase in ipsilateral proptosis and visual loss.

o (more apt to occur in patients who do not have NF1)


Management

• There is no universally accepted management for optic nerve glioma.

• Observation is indicated for patients with relatively good vision and stable radiographic appearance.

• Most patients show stability or very slow progression over years and sometimes showspontaneous regression.

• Chemotherapy is emerging as the first-line treatment when visual loss is severe at presentation or there is evidence of progression.


• Combination carboplatin and vincristine (Oncovin) is the most accepted regimen.

• Radiotherapy is controversial because of the inconclusive results and potential complications, including panhypopituitarism and mental retardation.

• stereotactic fractionated radiotherapy for optic nerve gliomas have been found to show good results


• Surgical excision may be indicated in patients with severe visual loss in association with disfiguring proptosis.

• Surgery has been advocated to prevent advancement into the chiasm; however, extension to the chiasm is rare.


MALIGNANT GLIOMA OF ADULTHOOD

• Since the advent of CT and MRI, the exceedingly rare malignant gliomas of the optic nerve and chiasm are more frequently being diagnosed before death.

• Almost invariably, patients present with rapidly progressive unilateral or bilateral visual loss.

• Eye pain or headache may accompany the visual loss and blindness occurs within weeks of onset.


Central scotomata

altitudinal field defects

and hemianopias have all been reported.

• At ophthalmoscopy,

the optic disk may be normal in appearance;

alternatively, edema

or atrophy of the optic disk may be present.


• Significant enhancement of the optic nerve after gadolinium infusion may indicate the presence of optic nerve glioma even before marked expansion of the anterior visual pathway

• Even with aggressive radiation therapy prolonging survival, there is invariably rapid spread of tumorintracranially, and death occurs within month.

• Histologically, the tumor may be characterized as either astrocytoma or glioblastoma multiforme. Cells spread in the subpialspace, resulting in progressive vascular occlusion and

demyelination.Wednesday, October 29, 2014 Department of Ophthalmology, JNMC 29

# Key Features

• Associated with painless and slowly progressive vision loss

• Diagnosis is typically in the first decade of life although they may occur at any age

• When associated with neurofibromatosis type 1, a familial preponderance may be seen

• Patients with and without neurofibromatosis type 1 who harbor optic nerve gliomas should be followed conservatively for sometime to determine rate of growth




Optic nerve sheath meningioma

INTRODUCTION

• Optic nerve sheath meningiomas (ONSM) are separated into two types: primary and secondary. The primary variety arises from the cap cells of the intraorbital or intracanalicular optic nerve sheath while the secondary form arises intracranially in the region of the sphenoid wing, tuberculum sella, or olfactory groove .

Saturday, August 22, 2015 Department of Ophthalmology, JNMC 32

PRIMARY OPTIC NERVE SHEATH MENINGIOMA

• Arises from proliferations of the meningoepithelialcells lining the sheath of the intraorbital or intracanalicular optic nerve

• Although these tumors are uncommon ( 1%-2% of all meningiomas), they account for one third of primary optic nerve tumors.

• Usually detected in adults age 40-50

• Women affected 3 times more than men


• 4%-7% of optic nerve sheath meningiomas occur in children.

• May occur more frequently in patients

with neurofibromatosis type 2 and may be bilateral.

• Bilateral tumors, albeit rare, tend to present at an earlier age


Clinical Features

• Patients may present with the classic diagnostic triad:


painless, slowly progressive monocular visual loss

optic atrophy

optociliary shunt vessels

Clinical Features

• There often is little if any proptosis.

• Roughly 50% will present with disk edema while the other half will demonstrate pallor.

• Some patients will also show choroidal folds due to compression behind the globe.

• Optociliary vein collaterals in the presence of vision loss and optic disk pallor should suggest the diagnosis of an ONSM


Clinical Features

• Visual fields typically show central and paracentral scotomata as well as altitudinal defects, which progress over time

• Despite the typical progression of reduction in visual function, some patients maintain stable acuity for years, or up to 30% may even improve.



(a) Fundus of a man with slowly progressive vision loss OD and neuro-imaging

consistent with an optic nerve sheath meningioma of the right optic nerve. The

optic disk is mild elevated and there are several cilioretinal shunt vessels of

the surface of the nerve substance. (b) The left nerve is normal.


optic disc atrophy, with optociliary shunt

vessels (retinochoroidal collaterals visible

at the 8 and 12 o'clock positions)

Neuroradiologic Features of Optic Nerve Sheath

Meningioma• Diffuse tubular enlargement of the optic nerve

• Sheath thickening and enhancement, with relative sparing of optic nerve substance ("tram track“ or " railroad track" signs)

• Apical expansion of the tumor

• Extradural tumor extension

• Calcification of the nerve sheath on CT scan


• Adjacent bony hyperostosis on CT scan

• Isointense or mildly hyperintense to brain on Tl- and T2-weighted MRI scan

• Prominent contrast enhancement on CT and MRI scan


Axial MRI through the

orbit with gadolinium

and fat suppression in a

35-year-old woman

demonstrating an

enhancing mass along

the right optic nerve.

There is also

depression of the

posterior globe on the

right and the right optic

nerve is visible

protruding into the

vitreous due to disk

edema.

Axial CT through the orbits of a 47-year-old

man complaining of transient visual

obscurations in the right eye. The scan

shows a hyperdense, calcified lesion over

the optic nerve, but the most anterior part

demonstrates the typical tram-tracking that

is seen with an optic nerve sheath

meningioma.

Axial CT through the orbits demonstrating

a bright, calcified lesion of the optic nerve

sheath on the left side. The lesion extends

most of the length of the orbital optic nerve

to the optic canal.

There is a cystic lesion of the optic nerve

on the right on this T1-weighted MRI scan

with gadolinium and fat suppression. The

mass was revealed pathologically to be an

ONSM. The optic disk is protruding into the

vitreous due to edema from the tumor.


CT scan reveals "tramtrack sign"; diffuse

enlargement of the right in traorbital optic

nerve extending anteriorly to the

globe, with enhancement of the optic nerve

sheath


Ring sign" in meningioma. Coronal

orbital MRI scan shows similar sheath

enhancement surrounding relatively

normal, darker optic nerve on the right.

Pathology

• Meningiomas probably arise from cap cells that line the outer arachnoidal surface.

• Two characteristic features- whorls and psammomabodies.

• Some meningiomas, called fibroblastic, consist of elongated cells, suggestive of fibroblasts.

• Syncytial tumors have indistinct cell borders, and those with prominent vessels are called angioblastic.



characteristic whorls and psammoma bodies of an optic nerve meningioma


Possible locations of intraorbital meningiomas.

Tumor cells may arise from the planum sphenoidale(1)

or from the optic canal (2) and migrate into the subdural space of the intraorbital optic

nerve. Tumors may also arise de novo from within the optic nerve sheaths and remain

intradural (3) or become exophytic masses (4).

Atopic nests of arachnoidal cells within the orbit (5 and 6) may also give rise to

meningiomas.

• characteristic neuro-imaging leave exact diagnosis rarely in doubt and biopsy can be deferred.

• due to the mimicry exhibited by metastatic breast tumors, biopsy in patients with an optic nerve sheath mass and a history of breast carcinoma.

• Breast tumors may also metastasize to an ONSM.

• Arachnoid cysts and sarcoidosis of the optic nerve sheath should also be considered


• Left alone, most unilateral ONSMs slowly but inexorably progress to produce blindness of the involved eye. However, this is not always the case. Some patients maintain stable vision for years .

• Intraorbital and intracanalicular meningiomasextend intracranially only rarely and are not fatal.

• In contrast, tumors that begin intracranially often extend to involve the chiasm and other structures adjacent to the optic nerve and may lead to blindness of the other eye.


Radiation therapy

• may also change the clinical appearance of the fundus.

• As the tumor shrinks, the optociliary venous collaterals may regress.

• several reports of radiation retinopathy as well as iritis, dry eye, or orbital pain.


Surgery

• not indicated due to the high likelihood of inducing blindness.

• (unavoidable dissection of the pial vascular supply of the optic nerve)

• should be reserved for those patients with eyes that are already blind or intracranial extension feared to extend to adjacent critical structures.


• Recently, several series have been published documenting treatment outcomes with stereotactic fractionated radiotherapy.

• indicated that some patients will have improvements in acuity, but more commonly enjoy improvement in visual field.

• A greater number of patients develop stability in their visual acuity and visual fields while only a small number worsen.


Introduction

• Secondary optic nerve meningiomas result from meningeal tumors that arise inside the intracranial vault near the sphenoid wing, tuberculum sella, and inferior frontal lobes. They cause vision loss typically due to direct compression of the optic nerve


Epidemiology

• It is very difficult to determine the epidemiology of these tumors.

• Most likely, these tumors are predominantly seen in middle-aged and older women.


Pathogenesis

• Recent advances in genetics have allowed researchers to investigate the frequency of mutations that arise in these tumors.

• Mutations have been found on chromosome 22, the chromosome linked with neurofibromatosis type 2.

• Up to 60% of sporadic meningiomas arise from inactivation of the NF2 tumor suppressor gene, leaving 40% caused by unknown factors.

• These deletions do not appear to be more frequent in more aggressive meningiomas.


• The non-NF2 meningiomas are more often of the meningothelial subtype and are located preferentially in the anterior skull base.

• Loss of heterozygosity of 18p may occur in a small number of sporadic meningiomas


• There are likely hormonal influences regarding the growth of meningiomas.

• The evidence that implicates gender-specific hormones in the pathogenesis of meningiomasemanates from data showing increased growth of meningiomas during pregnancy and change in size during menses.

• Estrogen receptor expression is lost or reduced in more benignly growing meningiomas,

• whereas loss of progesterone receptor expression is an indicator of early recurrence.The finding of progesterone receptors in only a few meningioma cells is a favorable prognostic indicator for prolonged disease-free survival.


• Human epidermal growth factor receptor type 2 (HER2) represents a well-known prognostic factor in various tumors such as breast carcinomas.

• rate of tumor recurrence shown to be significantly higher in meningiomas with HER2 over expression than in HER2-negative meningiomas


Clinical Presentation

• Sphenoid wing meningiomas typically are associated with much more severe proptosis than primary ONSM.

• Tuberculum sella meningiomas may also be associated with vision loss and cranial neuropathies causing diplopia.

• The clinical course for these tumors is slow. Rarely, patients who have undergone resection of a sphenoid wing meningioma may have intermittent reversal of postoperative proptosis.



Face shot of a woman complaining of proptosis of the left eye. Neuro-

imaging revealed a left sided sphenoid wing meningioma. The left eye

shows lid retraction and lagophthalmos with protrusion of the left globe. (b)

Picture taken from above the patient demonstrating the degree of proptosis

visually.

Radiologic Corelates• MRI is the imaging modality of choice in these

tumors.

• CT may show characteristic calcification within the mass on noncontrast imaging.

• MRI imaging with gadolinium will show more detail regarding a dural tail or other features, akin to a tumor of the dural sheath

• The tumors typically enhance homogeneously.

• Coronal sections through the cavernous sinus using T1-weighted images with gadolinium and fat suppression are ideal for identifying the degree of tumor spread.



Coronal T1-weighted MRI scan of the brain with gadolinium in a 48-year-old woman

with vision loss in the left eye. The scan demonstrates a large left sphenoid wing

meningioma and there are visible meningeal attachments laterally under the left

temporal lobe as well as medially through the cavernous sinus. There is midline shift of

the brain and hydrocephalus is noted in the left lateral ventricle in the temporal lobe.


Axial T1-weighted MRI scan of

the brain with gadolinium, but

without fat suppression in a 21-

year-old woman with left sided

vision loss. There is a large left

sphenoid wing meningioma that

extends into the left cavernous

sinus. There is also intraorbital

tumor, but due to the lack of fat

suppression on the scan, it is

difficult to tell what the extent of it

is.


Coronal T1-weighted MRI

scan of the brain with

gadolinium in a 54-year-old

woman complaining of

vision loss OD only. She

had frontal lobe findings

and a flat affect. There is a

very large falcine

meningioma that likely

arose from the right

olfactory groove although

this is difficult to prove on

this imaging. There is

midline shift and direct

compression on brain

tissue.

DIFFERENTIAL DIAGNOSIS • Tumors in region of the sella may be difficult to

differentiate from one another.

• Some masses originally thought to be meningiomasturn out to be pituitary tumors at pathological examination, and vice versa.

• Both of these tumors are benign and typically show fairly homogeneous enhancement,

• whereas more malignant tumors may show cystic changes and other features suggestive of a more aggressive character.

• Rarely, a suspected meningioma may be found to actually be Rosai–Dorfman disease.


TREATMENT

• Since these are slow growing tumors, conservative management until symptoms appear.

• visual fields, and regular MRI scans with gadoliniumenhancement are appropriate for patients who have good vision and no evidence of intracranial or intracanalicular extension of tumor.

• appropriate to follow a small amount of intracranial extension with serial MRI


• Craniotomy reserved for patients with documented progressive intracranial extension of tumor.

• A standard pterional craniotomy using microsurgical technique appears to provide the necessary exposure required for aggressive resection and with minimal complications.

• Radiation therapy may be coupled with conservative resection, and shows similar outcomes when compared to aggressive resection.


• Aggressive resection has the benefit of eliminating the risk of future complications of radiation toxicity, however.

• Complete surgical resection is often not possible in cases of sphenoid wing meningiomas.

• This is often due to invasion of the surrounding structures such as the cavernous sinus and orbit

• More of these cases require concurrent treatment with radiation therapy and are associated with tumorregrowth.


* Olson and colleagues

• Given the histopathological evidence of the presence of hormone receptors on meningioma cells, the effect of drugs targeting these receptors has been studied.

• In in vitro studies by, meningioma cells were inhibited by mifepristone (RU 486), estradiol-17β, and progesterone.

• Tamoxifen stimulated growth of meningioma cells in vitro.


# Key Features

• Associated with painless and slowly progressive vision loss

• Average age of onset in the fifth decade of life

• Minimal proptosis, if any

• Optociliary vein collaterals may be present on the optic disk

• Neuroimaging is the mainstay for diagnosis in a typical case

• Radiation is treatment of choice in an eye with documented progressive vision loss



Melanocytoma


• Melanocytomas are benign melanocytic tumors that occur typically on the surface of the optic disk, in the anterior uveal tract, or, more rarely, in the choroid, although they have been reported to occur in the sclera or conjunctiva.

• Also termed ‘magnocellular naevus’, which is also appropriate. This term is concordant with the histopathologic appearance of these lesions which are composed of large, regular cells.


Melanocytoma of Disc

• Relatively rare tumors with unknown prevalence

• Mean age at diagnosis 40-50 years

• Slight female predominance

• Generally unilateral

• Left and right side affected with similar frequency


Clinical Presentation• The clinical presentation of melanocytomas

depends on their size and extension.

• may be confined to the optic disk or

• may infiltrate the adjacent choroid and optic disk without prolapsing through the retina


Subretinal melanocytoma

situated on the optic disk

and adjacent choroid. (a)

Ophthalmoscopy. (b)

Fluorescein angiography,

early phase

• May infiltrate the retina, thereby resulting in the classical appearance of a filamentous border


Large melanocytoma situated on the optic

disk and choroid and invading the nerve

fiber layer.

• they can also induce papilledema and may invade the optic nerve.


Melanocytoma of the optic disk associated with papilledema. (a) Ophthalmoscopy.

(b) Fluorescein angiography, arteriovenous phase

• lesions are invariably dark brown or black and, apart from rare exceptions, coloration is homogeneous.

• Size variable, generally do not exceed 2–3 mm in greatest dimension.

• Adjacent choroid involved in 47-86% of cases

• retina is involved in 30-67% of cases.

• That portion of the optic disk that is spared by the tumor may appear physiologic or, in ∼25% of the cases, may reveal papilledema on ophthalmoscopicexamination


• Another 25% of the cases will show papilledema only on fluorescein angiography

• The tumor can, in rare cases, be accompanied by a serous retinal detachment, retinal edema, lipid deposits, or intraretinal haemorrhage and, more rarely, by polypoidal choroidal vasculopathy

• The vitreous is generally clear, but pigment dispersion secondary to tumor necrosis may be observed and may, in some cases, extend to the anterior chamber



Melanocytoma of the optic disk associated

with marked pigment dispersion in the

vitreous.

• About 75% of the patients are asymptomatic, and the tumor is discovered incidentally.

• Blurred vision, floaters, flashes, metamorphopsias, or micropsias are the symptoms most frequently reported in the other cases.

• Visual field examination often demonstrates enlargement of the blind spot or peripheral or fascicular field defects, or, more rarely, major defects that cause tunnel vision.

• No correlation has been established between tumorsize and tumor extension, or between the presence of papilledema and the size of the visual field defect.


• Melanocytoma of the optic disk has been reported in association with ocular melanocytosis,congenitalhypertrophy of the pigment epithelium, choroidalnevus, and retinitis pigmentosa


Investigations• Ophthalmoscopy generally sufficient to establish the

diagnosis of melanocytoma. The various complementary investigations are performed primarily to document the shape and extension of the tumor and to detect possible complications.


• FLUORESCEIN ANGIOGRAPHY

• The part of the tumor that is invading the retina remains hypofluorescent on all phases of fluorescein angiography. A fine network of telangiectaticcapillaries is occasionally observed on the surface of the tumor, and the filamentous edges are clearly visible. In contrast, the part of the tumor invading the choroid and situated underneath the pigment epithelium has the same angiographic features as do choroidal nevi.

• Fluorescein angiography can, however, detect or confirm the presence of papilledema.


• B-SCAN OCULAR ULTRASOUND

• This examination can be used to measure tumor thickness, but does not provide any additional information.

• HEIDELBERG RETINA TOMOGRAPHY

• This examination can be used to precisely measure the tumor surface in three dimensions, and is therefore useful to detect any changes in tumor volume



HRT, tumor apex/retinal

surface distance: 0.5 mm,

and study of the horizontal

and vertical profile of the

tumor

• Melanocytomas are composed mainly of intensely pigmented, large polyhedral nevus cells. On ultrastructural examination, the cytoplasm contains few organelles, but a large number of giant melanosomes. The nucleus is oval, generally without a nucleolus, and there is a low nucleocytoplasmicratio


DIFFERENTIAL DIAGNOSIS• Certain benign or malignant tumors of the choroid,

pigment epithelium, and optic disk, as well as certain malformations, can mimic melanocytoma.

• The main differential diagnoses are choroidalmelanoma adjacent to and invading the optic disk, primary melanoma of the optic disk, and adenoma or adenocarcinoma of the juxtapapillary pigment epithelium.


CLINICAL COURSE AND COMPLICATIONS

• Melanocytomas of the optic disk are benign tumors that generally remain stationary.

• Over a long period of observation, ∼40% of these tumors show some slow growth,

• and ∼2% undergo malignant transformation.

• Progression of a melanocytoma may be complicated by partial or total visual loss due to partial or total vascular occlusion or nerve fiber necrosis, both of which are secondary to pressure exerted by thetumor.Wednesday, October 29, 2014 Department of Ophthalmology, JNMC 90

• Visual loss may occasionally be transient.

• In conclusion, although melanocytomas of the optic disk are benign, they do present a low risk of malignant transformation.

• They can also induce complications that lead to severe loss of visual function, and therefore require close surveillance.



Malignant astrocytomas

Malignant astrocytomas

• Rare neoplasms involving the anterior visual pathway

• almost always occur in adulthood, with a mean age in the 60s

• they are minimally more common in males ( 1.3:1).

• Patients present with acute onset of pain and either unilateral or bilateral visual loss, depending on whether the optic nerve or the chiasm is initially involved.


• With unilateral lesions, the second eye is invariably involved within weeks.

• optic disc may be normal or pale at presentation ,

• but in cases of more anterior tumors, retinal venous occlusive disease and disc edema are common secondary to obstruction of the central retinal vein within the intraorbital optic nerve


• An MRI scan most often shows diffuse intrinsic enlargement and enhancement of the affected optic nerves, chiasm, and optic tracts, with inhomogenecity due to cystic spaces within the tumor

• Occasionally, a large exophytic component may encroach on the suprasellar cistern.

• Histologically, malignant optic nerve gliomas are classified as anaplastic astrocytomas or glioblastomamultiforme.


• Visual loss is severe and rapidly progressive.

• Treatment is rarely successful, although radiotherapy and chemotherapy have been attempted, with blindness usually developing 2-4 months after onset of visual loss.

• The tumor is aggressively infiltrative, and death from hypothalamic and brainstem involvement usually occurs within 6- 12 months.



Astrocytic Hamartoma

• Astrocytic hamartomas of the retina, most common in tuberous sclerosis and neurofibromatosis, may take the form of so-called mulberry lesions.

• When located adjacent to the disc, they may closely resemble optic disc drusens, and in early reports they were termed giant drusen of the optic disc.

• In contrast to true optic disc drusens, disc hamartomas originate at the disc margin, with extension to the peripapillary retina arise in the inner retinal layers and typically obscure retinal vessels

• may have a fleshy, pinkish component

• do not autofluoresce and may show tumorlikevascularity on fluorescein angiography


Optic disc drusen


Astrocytic hamartoma


LYMPHORETICULAR TUMORS

LYMPHORETICULAR TUMORS

• Leukemia is a well-recognized cause of infiltrative optic neuropathy.

• Vision loss may occur abruptly or over the course of several days and is often bilateral.

• Many patients have a known history of leukemia at the time of diagnosis.

• The fundus may show abundant retinal hemorrhages and bilateral optic nerve edema



Fundus of the right eye of a 21-year-old man with acute lymphocytic

leukemia. There is severe edema of the nerve, exudates, and retinal

hemorrhages due to carcinomatous invasion of the optic nerve and its

sheath. (b) The left fundus shows much more severe retinal hemorrhages.

• Although a spinal tap is required to confirm the diagnosis of leukemic invasion, an MRI can show signs characteristic of infiltration.


Axial MRI through the orbits with gadolinium and fat suppression, revealing

enhancement and enlargement of the optic nerve sheaths bilaterally in a 21-year-old

man with acute lymphocytic leukemia. He had severe vision loss. (b) Coronal MRI

through the orbits showing a cross section of the enhancement and enlargement of

the optic nerve sheaths in the same patient.


METASTATIC TUMORS OF THE OPTIC NERVE

METASTATIC TUMORS OF THE OPTIC NERVE

• A number of carcinomas are known to metastasize to the optic nerve.

• Patients frequently present with only mild vision loss

• neuro-imaging may initially appear normal or with only subtle findings.

• Common primaries include breast, lung, and bowel tumors.


• Renal carcinomas may also cause an optic neuropathy.

• These tumors may infiltrate the optic nerve, producing symptoms either as an initial manifestation or as part of a more generalized meningeal involvement.


Take home message

• Not infrequently, the ophthalmologist is called on to determine whether or not visual loss is caused by infiltrative or compressive lesions of the anterior visual pathway. This is determined through careful clinical evaluation of the visual acuity, color vision, pupils, visual fields, and fundus. Knowledge of the more common tumors will assist the ophthalmologist in advising patients on a course of action, and deciding which patients should be followed and which require referral to neurosurgeons or radiation oncologists


Bibliography


# Anatomy and Physiology of the Eye by AK Khurana; 2nd Edition

# Albert Jakobiec’s Principles and Practice of Ophthalmology. Section 14, Section 17; 3rd Edition

# American Academy of Ophthalmology BCSC. Section 5; 2011-2012

# Yanoff & Duker Ophthalmology; 3rd Edition

THANKYOU

October 29, 2014 Department of Ophthalmology, JNMC 110

Optic nerve tumors ppt

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