Craniopharyngiomas and Suprasellar Tumors

Shikher Shrestha

NINAS

ANATOMY QUICK RUN THROUGH

CRASH COURSE!!!

Suprasellar Tumors

1. Tumors of dysembryogenic origin

Craniopharyngioma, Epidermoid, Dermoid, Hamartoma,

Germ Cell tumor, Rathke’s cleft cyst

2. Tumors originating from tissues of suprasellar structures

Gliomas of visual pathways and hypothalamus, pituicytoma, granular cell tumor of neurohypophysis, meningioma

3. Tumors extending into the suprasellar space secondarily

Pituitary adenoma, Rathke’s cleft cyst

4. Systemic tumors affecting the CNS

CNS metastasis, lymphoma, leukemia

Most common - Craniopharyngioma

Chiasmatic/hypothalamic glioma

Craniopharyngiomas

Benign, extra-axial epithelial tumors

Aggressive clinical course – significant morbidity and shortened life expectancy

2 intentions of Rx

to remove totally whenever technically possible

intentional incomplete removal and radiotherapy to lower surgical morbidity

radical removal – only in patients where hypothalamus NOT involved

Incidence..

1-4.6% of all intracranial tumors

13% of suprasellar tumors

0.5 – 2.5 new cases per million population per year

Papillary type – exclusively in adults 40-55 yrs

Adamantinomatous – bimodal age distribution with peaks in children aged 5-15 yrs and adult aged 40-55 yrs

Children – 2.5-13% of all tumors and 56% of sellar-chiasmatictumors

Tumor Development..

Erdheim Embryogenic Theory:

Origin – remnant of craniopharyngeal duct or Rathke’s pouch

Epithelial cell rests of the vanishing hypohyseal duct remain

adherent to the neuroepithelium before the pia is formed

Arise from the anterosuperior surface of the adenohypophysis

Grekhov: 4 groups according to the point of original growth

infrasellar

intrasellar (intrasellar and suprasellar)

pituitary stalk

infundibular

Metaplastic theory:

Metaplasia of mature adenohypophysis cells nests of

squamous epithelium

Theory explains:

adamantinomatous type to embryonic remnants vs

papillary type (adult) - metaplasia

Pathology and Surgical Anatomy..

Microscopic Anatomy:

Adamantinomatous

complex epithelial lesion resembling enamel pulp of developing teeth

Pallisading peripheral layer of epithelium

Hydropic vacuolation of inner layer

Loose stellate reticular zone containing nodules of plump keratinocytes “wet keratin”

Dystrophic calcification

Areas of cholesterol deposits

Microscopic anatomy contd..

Papillary:

simple squamous epithelium

villous fibrovascular stroma forming papillae

Both variants:

Brain parenchyma – gliotic with profuse Rosenthal fibers

Macroscopic anatomy..

Solid tumors with a variable, sometimes cystic or multicystic

component

Adamantinomatous – cholesterol rich, machine oil like, thick

brownish yellow-green fluid, crumbly debris

Occasional calcification

Papillary type – lacks cystic component

Surgical Anatomy..

Infradiaphragmatic tumor – grows below the sellar diaphragm

Supradiaphragmatic

Topography depends on

length of optic nerve

position of the chiasm

Infradiaphragmatic..

Intrasellar

Upward displacement of sellar diaphragm and arachnoid

Grows below the chiasm, compresses and displaces upward as

well as the floor of the third ventricle

Supradiaphragmatic..

Point of orignial growth in the stalk or inside the infundibulum

(most basal part of the floor of IIIrd ventricle)

Pituitary stalk suprasellar extraventricular

extends anteriorly to the chiasm b/t optic nerves

retrochiasmatic if prefixed chiasm

Infundibulum intraventricular and extraventricular (IEVC)

grows between the optic tracts

disrupts third ventricular floor at an early stage

partially inside and partially outside IIIrd ventricle

In IEVC

most affected region of IIIrd ventricle – tuber (central) part

compresses mammillary bodies

infundibulum (median eminence) less frequently destroyed

commonly located exclusively behind the chiasm

small part of tumor may extend below the chiasm or b/t optic

nerves

Exclusively Intraventricular..

rare subtype entirely within the ventricular cavity

attached to a partially atrophied floor of IIIrd ventricle

Clinical Presentation..

Most common S&S –

Endocrine deficiencies (90%) in children

Visual disturbances (96%) in adults

Hypothalamic disorders – obesity – children

Mental disorders

Increased ICP

Visual Problems:

defects In visual fields

bitemporal hemianopia, homonymous hemianopia, concentric contractions of fields, central or paracentralscotoma

decreased visual acuity

Compression not only by tumor but also by A1 or AcomA due to displacement of chiasm towards those arteries

Compression of lower chiasmatic arteries may also be the cause

Concentric narrowing – due to optic atrophy from long standing

hypertension

Endocrinopathies:

Growth deceleration; Delayed puberty; Decreased sexual drive

90% men – impotence; most women – amenorrhea

Diabetes insipidus – presurgery – 8-35% cases

Hyperprolactinemia – 40%

Obesity – 25% - due to growth hormone insufficiency

Cognitive impairment, personality changes

Memory disturbances – lesion in mammillary body

(mammillary thalamic tract)

Radiographic Diagnosis..

Infradiaphragmatic (intrasellar, infrasellar, suprasellar)

enlarge the sella similar to pituitary adenoma

Supradiaphramatic – displace diaphragm and pituitary downward

Calcifications – 85% childhood/ 40% adult types

Egg shell calcification of the wall

Cyst may appear solid if they contain sufficient quantity of suspended calcium salts

Contrast enhancement of solid component and cyst wall

MRI – heterogenous mass

solid part – isointense on T1 + contrast enhancement

Hyperintense ring enhancement of cyst wall

Hyperintense cyst cavity on T1 if high protein content

Relation to sella and diaphragm – best in coronal view

AcomA – mostly in upper posterior surface of chiasm

Presence or absence of hydrocephalus

Modalities and Options for Treatment..

Two different management attitudes:

Radical surgical excision

Intentional incomplete (subtotal or partial) excision and

radiotherapy

Radical Surgery vs Conservative Surgery

Radical surgery:

Considerably lower recurrence rate after complete tumor

removal

Worse outcome of second surgery

Conservative surgery:

lower incidence of endocrine deficit

hypothalamic insufficiency and major disability limited

higher rate of local tumor control by incorporation of

radiotherapy

Adjuvant radiotherapy..

Recurrence free survival increased from 38% to 77% after

radiotherapy

No agreement concerning timing – early vs. no radiation for stable

residual tumor

Conventional radiation

Advanced: 3D conformal, intensity modulated and stereotactic

54 Gy in 30 fractions for tolerance of optic chiasm; if single

targeted dose then 8 Gy

Instillation of solution of beta particle emitting radioactive

isotopes – yttrium90, gold198 and phosphorus32

AE:

damage to pituitary and hypothalamus and visual structures

moyomoya syndrome, cavernous malformation

secondary malignant astrocytoma

Chemotherapy..

Intracystic bleomycin in cystic craniopharyngiomas

cyst wall thickens and contracts, pulling away from brain

structures facilitating cyst removal

highly toxic for neural structures if allowed to leak

Other techniques..

VP shunt

EVD

Stereotactic technique for cyst evacuation, instillation of

radioisotopes or bleomycin into the tumor cyst

Ommaya reservoir – for repeatedly enlarging cyst enables

simple evacuation of cyst contents

In general..

Radical removal in cases of extraventricular craniopharyngiomas

and contraindicated when the tumor is intraventricular

Imaging studies do not show whether the tumor is simply

compressing the hypothalamus or invading it

Final decision about the extent of safe removal cannot be made

before the operation

Surgery..

Accessibility does not mean resectability

Hypothalamic structure should be avoided

Intrasellar and Intrasellar + Suprasellar Cranio..

Intrasellar – transsphenoidal route

Intra+suprasellar – transsphenoidal

giant/ dumbbell or multinodular shaped extended transsphenoidal allows removal of supradiaphragmatic also

Unilateral paraseptal, sublabial approach

Large opening of sphenoid sinus and sellar floor

Neuronavigation guided

Tumor does not invade cavernous sinus as the pituitary adenomas do

Capsule adherent to dura separated by pulling into the sellar cavity and bluntly dissecting it

free

If eggshell calcification – caution while removal

Preservation of stalk may necessitate leaving behind a piece of capsule

Suprasellar Extraventricular..

Superior displacement of chiasm

Removal of tumor through –

prechiasmatcic space between optic nerves

opticocarotid triangle

lateral to carotid

Unilateral subfrontal approach / pterional approach

Removal through lamina terminalis would jeopardize

hypothalamic structures of the floor of IIIrd ventricle

retrochiasmatic approach safe

Orbitozygomatic and transpetrosal approach may be of great help

Bifrontal craniotomy for giant multicystic tumor

Approach preferably through nondominant side

Medial part of sylvian fissure may required to be opened

Prevent leakage of cyst content to the subarachnoid space by

cotton patty

Solid part of the tumor removed piecemeal

Removal of calcified portion of tumor from the wall of the carotid may be dangerous

Extreme care to look for minute perforating vessels, the branches of the supraclinoid carotid and the PcomA supplying the visual pathways and the hypothalamus

Branches of A1 and AcomA in close contact with tumors growing in front of the chiasm

Part of capsule left behind if attached to these vessels

Capsule firmly adherent to the IIIrd ventricular floor or pia of hypothalamus – left behind

Removal of posterior pole does not pose problem as the basilar

artery and its branches and brainstem protected by liliequist’s

membrane

Intraventricular and Extraventricular

Craniopharyngiomas..

Atrophied hypothalamic structures within the remnant of the floor of the third ventricle displaced around the equator of the tumor

Both extracerebral and transventricular approach

Low position of chiasm and narrow opticocarotid triangle in such setting preclude extracerebral tumor exposure

Central lower part of lamina terminalis is often composed of gliotictissue represents capsule of anterior pole of tumor

Its opening between chiasm and AcomA good exposure of anterior and basal parts of intraventricular mass

CUSA may be used to break the calcified basal part

Piecemeal removal of basal part pituitary stalk may be seen

below the chiasm after removal of basal part

Brainstem, basilar artery and displaced mammillary bodies can

thus be seen from the Liliequist’s membrane

Remnants of infundibulum and tuber may also be seen

If no plane of cleavage between gliotic tumor capsule and third

ventricular floor remnant, then tumor capsule left behind

Majority can be removed by trans laminaterminalis approach

adv: good access to the postero-basal expansion into the CP angle

disadv: insufficient exposure of the superoposterior part of the third ventricle

Transcallosal approach for larger tumor

adv: removal of tumor from upper pole devoid of neural structures

limitations: anteroinferior part of tumor may not be exposed

Usually tumor only touches fornix without invading it

Combination approach hence useful

Removal of tumor may be staged; one setting 2 craniotomies or 1

large craniotomy

Transfrontal transcortical is usually avoided for seizure risks

Intraventricular Craniopharyngiomas..

Rare

Push the third ventricle floor downward

Extracerebral approach – jeopardize hypothalamic strucutures

May be approached by opening the lamina terminalis or through

the foramina of Monro

Tumor adherence to lateral wall of third ventricle less pronounced

Perioperative Management and Management of

Complications..

Preoperative Pituitary insufficiency Perioperative hormonal replacement

Hydrocortisone 400mg on the day of surgery 100 mg before surgery, 100 mg during tumor removal and rest after the operation

If uneventful postop recovery – dose of hydrocortisone reduced to 1/5 th on the fifth post operative day

Complications: hyperpyrexia, seizures, decreased level of consciousness, DI, hypernatremia, hypokalemia

Due to pituitary stalk disruption and damage of osmoreceptors in anterior hypothalamus

DI, SIADH, CSW – identified and appropriately corrected

Bleeding in the tumor bed

VP shunt if persistent hydrocephalus

Long term results..

Outcome depends on the location of tumor

Overall surgical mortality <4%

In a series with >60% large or giant tumors, radical tumor removal

achieved in 90% with overall mortality of 9% and recurrence rate

of 7%

Recurrences and their management..

Most important factor for recurrence extent of resection

Removal of recurrent tumor lower cure rate and higher

complication rate because of scarring and adherence

Radiation therapy as the primary Rx for recurrence

Some residual tumors may remain stable for years without

adjuvant therapy

Morbidity rate..

Pituitary hormone deficiency

Hormonal replacement required in 85-100% of cases

GH deficiency 100%

Hypogonadism 65-80%

hypothyroidism 38.5-95%

hypocorticism 55.2-78.1%

new post surgical DI 56%

Obesity 58-62%

significant school problems 50%

postsurgical visual impairment 5-66%

Cysts of Suprasellar region..

Epidermoid and Dermoid Cysts:

arise from the inclusion of ectodermally committed cells at the

time of closure of the neural groove

epidermoid – occurs in older age group and shows slow

progression

multilayered keratinized, squamous epithelium

that rests on an outer layer of collagen

contents – solid, flaky and keratinous

occasional degeneration of center with flakes

replaced by greasy brownish fluid containing cholesterol crystal

Clinical presentation..

Similar to craniopharyngioma

Less commonly, aseptic meningitis due to leakage of cyst content

Both T1 and T2 – slightly more hyperintense compared to CSF containing arachnoid cyst

Dermoid cyst – signal intensity similar to lipoma

Rx – ideally complete removal

if dense adherence – should not attempt radical resection

incompletely resected – will slowly recur

caution – chemical meningitis during surgery –

cottonoids; voluminous NS irrigation, local steroids

Rathke’s Cleft Cyst..

Microscopic cysts between anterior and posterior lobes of the mature pituitary gland

Remnants of cyst also persists above the level of sellar diaphragm in the stalk

Lining – columnar or cuboidal cells with apical cilia, stratified at places; keratinization NOT seen

Relatively common incidental finding

Symptoms – headache (common), compression of pituitary, optic chiasm and hypothalamus – related symptoms

Recurrent episodes of Aseptic meningitis – cyst leakage into the

subarachnoid space

Mean age: 4th decade (2nd to 8th decade)

Females more commonly affected

MRI: single, uniloculated, round, sharply defined intra or

suprasellar mass typically lying anteriorly to the infundibular stalk

variable T1 and T2 intensity depending on cyst content

no contrast enhancement or calcifications

Rx:

Transsphenoidal approach

partial resection of cyst wall and evacuation of contents

endoscope considered the best

radical resection endangers the stalk

Craniotomy for suprasellar lesion

Gliomas of the Chiasm and Hypothalamus

May start from optic chiasm to involve hypothalamus or vice versa

Impossible to determine clinically and radiologically, from where it

started

Referred to as a single disease – opticchiasmatic-hypothalamic

gliomas; optic pathway/hypothalamic gliomas

Konovalov et. Al: Nodular type and Diffuse type

5 types of Nodular variant..

1. Tumors with predominant anterior growth

2. Tumors growing anteriorly and penetrating the third ventricle

3. Tumors with the main part occupying the third ventricle but

infiltrating the chiasm as well

4. Tumors of optic tract

5. Gliomas of the floor of the third ventricle

90% in pediatric age group

Usual age: 2-4 yrs

Histology: 60% pilocytic and 40% fibrillary

8% anaplastic – group 5 nodular (3rd ventricle)

Tumors grow in the subependymal layer of lateral wall of the 3rd

ventricle break through it later grows inside 3rd ventricle

MRI – hypointense in T1 and hyperintense in T2 and FLAIR; large

tumors heterogenous with solid and cystic components

Clinical Presentation..

Progressive loss of vision with slow development of optic atrophy

Typical for chiasmatic glioma: defects in temporal half of the visual field of the “better” eye with practical blindness in the other eye

DI, obesity and genital underdevelopment hypothalamic involvement

Diencephalic syndrome (25%) in children less than 3 yrs heralded by:

emaciation and loss of subcutaneous fat, which contrasts with normal height and normal muscle mass

normal appetite; child alert, vigorous, hyperactive, euphoric

nystagmoid eye movement

Management:

Highly unpredictable natural course

May remain static or quiescent for many years; others might have

aggressive course increasing rapidly

Involution after partial removal has been documented

Association with NF 1 have been reported as better prognosis by

some and unfavorable prognosis by other authors

Some recommend conservative surgery or biopsy followed by

radio or chemotherapy while other stress more radical resection

Surgery..

Main aim: histological diagnosis and restoration of CSF pathway

patency

Tendency towards more radical resection for better outcome and

lower recurrence rate

Indication:

nodular or exophytic growth without optic tract involvement or

visual failure

Surgical approach and extent of tumor removal..

Various approaches to access suprasellar region:

subfrontal

pterional

subtemporal

anterior interhemispheric

transcallosal

combined transcallosal-subfrontal

transcallosal-pterional

Most common tumor in this location: pilocytic astrocytoma

Tumor inside the third ventricle NOT intimately adherent to the

lateral wall is removed

Superoposterior part of tumor might not be reached by

translamina terminalis approach; for that it may be combined with

transcallosal approach

Management of hydrocephalus..

Shunt insertion after tumor resection may be necessary

Preoperative CSF diversion may also be necessary in acute

setting

Adjuvant therapy..

Radiotherapy and chemotherapy often recommended

Radiation therapy arrests tumor growth

Median dose 54 Gy for chiasmatic glioma and 55-60 Gy for hypothalamic tumors

Efficacy reported as low as 40%

Responds surprisingly well to chemotherapy – tumor shrinkage and stabilization or even disappearance in some instance

Radiotherapy postponed beyond 5 yrs to limit side effects

Complications..

Acute hypothalamic insufficiency (most common)

Careful monitoring and correction of metabolic disorders

Bleeding into the tumor bed needs evacuation

Brain collapse and subdural effusion and blood collection

Tension pneumocephalus

Outcome..

Radicality of surgery influences long term outcome

5 and 10 yrs PFS for radical, subtotal and partial surgery – 100%, 74% and 51% respectively

Visual function improvement 14%

Worsening of visual function 23%

DI 12%

Precocious puberty 18%

Hypopituitarism and memory disturbances

Germinomas..

Accounts to 0.5% of all CNS tumors and 3% CNS tumors in children

Occurs in midline intracranial axis that traverses 3rd ventricle

Occasionally, synchronous pineal and suprasellar region tumor

Important to distinguish pure germinomas from admixture of other germ cell tumors or syncytiotrophoblastic giant cell tumors secreting hCG

Pure germinomas are non secreting type whereas nongerminomatous GCT secret AFP and bHCG

Infiltrative lesions involving floor of 3rd ventricle, pituitary stalk,

pituitary gland and optic pathways

Clinical manifestations:

visual disturbances, DI, obesity, pituitary insufficiency

precocious puberty and hydrocephalus

MRI – T1 – hypo to isointense and T2 – iso to hyperintense

intense contrast enhancement

CSF borne metastasis along ventricular surfaces and

subarachnoid space

Extremely radiosensitive

Biological biopsy:

in the past – single fractionated dose delivered to the tumor site radiographic response suggested tumor of germinal origin high dose focal radiotherapy initiated

craniospinal irradiation

Chemotherapy: 80% complete radiographic response

3 course of carboplatin-etoposide chemotherapy followed by 24 Gyradiation

Hypothalamic hamartomas..

Non-neoplastic, non progressive congenital malformations

Composed of disordered neurons, glial cells, & myelinated tracts

Occurs in 2 general locations:

tuber cinerum – usually pedunculated

within 3rd ventricle – sessile

Pedunculated – more likely small (<2cm); causes precocious

puberty but no other neurological symptoms

gonadotropin-releasing factors positive

Sessile: - more often large (2-5 cm)

associated with gelastic seizures

seizures are subsequently longer duration develops

secondary, generalized epileptic manifestation

cognitive deterioration and behavioral problems

2/3 rd children – developmental delays

½ - precocious puberty

MRI:

T1 – isointense to mildly hypointense

T2 – iso to hyperintense

no contrast enhancement

Pedunculated:

approached via pterional or subtemporal route

50% patients cured after total removal

subtotal removal – rarely leads to clinical or hormonal cure

Sessile:

transcallosal approach or trans lamina terminalis

endoscopic removal

complete removal controls or cures seizure, improves

behavior, school performance and quality of life

main difficulty in surgery is to differentiate hamartoma from

normal brain tissue

Pituicytomas (tumor of neurohypophysis)

Originate in pituicytes (modified glial cells) of posterior pituitary

gland and infundibulum

Start to grow within or above sella

Historically, terms choristoma and infundibuloma also used

Benign (WHO grade I)

Extremely rare; occurs in adult; granular cell tumor (other tumor

of posterior pituitary) can rarely occur in children

Clinical presentation:

visual field deficit

hypopituitarism

galactorrhea (stalk effect)

headache

DI (rare)

Firm and vascular nature without obvious dissection plane may

hamper gross total resection

Significant bleeding risk

MRI – isointense to T1 and T2 and significant contrast enhancement

Thank you!!!