Pineal gland is essentially an extra axial midline structure lying at the roof of dienchephalon rostral to the quadrigeminal cistern surrounded by important neurovascular structure, occurring in the geometric center of brain with same depth of trajectory had made the surgery in this region a formidable challenge to neurosurgeons, however radical resection must be the goal in selected pathologies, if not pure germ cell tumor.
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APPROACH TO PINEAL TUMOR
1. DR. SURESH BISHOKARMA
MS, MCH (NEUROSURGERY)
Department of Neurosurgery
Upendra Devkota Memorial National Institute of Neurological and Allied Sciences
Bansbari, Kathmandu, Nepal
PINEAL NEOPLASM
2. TIMELINE ON PINEAL GLAND
First brain
dissection and to
describe pineal
gland
Descartes
V.
Horsley
1910
Seat of the human soul
Pioneered intratentorial supracerebellar approach
Dandy
1921
Krause
1913
First attempted resection
Herophilus
335-280
B.C
Van
Wagenen
1931
Trancortical transventricular
approach
Studnicka
1905
Glandular function
Pioneered occipital transcallosal approach
Melatonin dicovered
Lerne
r
1958
Poppen
1960
Stein
1971
Occipital transtentorial
approach
Revolutionised Krause ITSC approach
Pinealis – pine cone
Vedas – one of the 7 centers of vital energy
“I have never succeeded in exposing pineal region tumor
sufficiently well to justify an attempt to remove it”
Cushing (1932)
3. ~8 mm long and 4 mm,
Midline, quadrigeminal cistern
Geometric center of brain: same depth of trajectory; Difficult to access
Extra-axial structure: readily resectable plane.
Diverse pathologies: neoplastic and non neoplastic lesions.
Surrounds: Neurovascular structure.
Pineal mass originate infratentorially and expand into the 3rd ventricle, thalamus or
quadrigeminal plate or midbrain.
ANATOMY
4. Gland is located in dienchephalic roof at the posterior extremity to 3rd ventricle between the
habenular commissure and the posterior commissure, lies between the superior colliculi and
basal to the splenium of the corpus callosum.
Anteriorly: Posterior commisure and posterior part of 3rd ventricle.
Posteriorly: Habernular commisure and cerebral vermis
Superiorly: Splenium
Inferiorly: Quadrigeminal plate and tectum
Intimate with Velum interpositum
Boundaries of pineal region
6. ICV
Rosenthal
Pre centralcerebellar
Internal occipital
Posterior mesenchephalic
Posterior ventricular
GALEN
INF SAG. SINUS
STRAIGHT SINUS
The great vein of Galen and its tributaries form a roof-like, dense venous network above the
pineal body and the quadrigeminal plate.
VENOUS DRAINAGE
7. Reptiles: Photoreceptor
Hormone secretion for circadian rhythms
Neurotransmitter secretory function
Inhibits gonadal development and regulates menstruation, adrenal function, and thyroid function.
It is innervated by sympathetic nerves from the superior cervical ganglion that release norepinephrine
to increase the pineal gland’s melatonin secretion.
Light stimuli thereby reach the pineal gland from the retina via a polysynaptic pathway and affect the
production of the neuroendocrine substance, melatonin.
The production of melatonin is inhibited by light.
Apparently, in many animals the major function of the pineal gland is to regulate the reproductive cycle; in
fall and winter when days are short, more melatonin is produced, causing a gonad suppressing effect.
The exact function of the pineal gland in humans remains unclear.
Recent studies could prove a diagnostic value of the melatonin profile in case of tumors of the pineal
region.
These studies showed a dramatically reduced melatonin rhythm in cases of undifferentiated or invasive
tumors as well as the absence of melatonin variation as a consequence of pineal distortion after surgery.
Also, the evidence for melatonin deficiency is recognized as a predictive factor to prevent post-
pinealectomy syndrome. The absence of production of melatonin, as after pinealectomy, causes a “Jet-lag-
like ” syndrome.
Function of pineal gland
8. • Rare: 0.4 to 1.0 % (adults) and 3-8 % in children.
• Most common type:
• Germ cell tumors.
• Pineal parenchymal cell tumors and glial cell tumor.
• Other : Meningiomas, PNET, Neurocytomas, Hemangioblastomas, Cavernomas and
Mets.
PINEAL TUMORS
9. TYPES OF PINEAL TUMORS: 2007 WHO
Tumor Origin Frequency
1. Germ Cell Tumors:
A. Germinoma: 50-70% of GCT
B. Non-Germinomatous GCT: 30-35% of GCT.
i. Embryonal carcinoma
ii. Yolk sac tumor (endodermal sinus tumor)
iii. Choriocarcinoma
iv. Teratoma: Mature, Immature, Teratoma with Malignant Transformation
v. Mixed
Rest of germ cells ~60%
2. Pineal Parenchymal Tumors
i. Pineocytoma (WHO grade I): 45%
ii. Pineal parenchymal tumor of intermediate differentiation (WHO grade II or III): 10%
iii. Pinealoblastoma (WHO grade IV) :45%
iv. Papillary tumor of pineal region: Ependymal cell origin: 10%
Pineal glandular tissue 14-30%
3. Tumors of Supportive cells (Glial cell, mesenchymal, ependymal, arachnoid) and Adjacent Structures
~10%
• Astrocytoma: Glial cell or pleuripotent pineal parenchymal cells
• Glioma (glioblastoma or oligodendroglioma)
• Medulloepithelioma
Glial cells
• Ependymoma
• Choroid plexus papilloma
Ependymal lining
• Meningioma: Velum interpositum, Falx, tentorium Arachnoid cells
• Hemangioma
• Hemangiopericytoma or blastoma
• Chemodectoma: from Sympathetic plexus
• Craniopharyngioma
Vascular cells
• Malignant solitary fibrous tumor Mesenchymal tissue Very rare
4. Non-neoplastic Tumor-like Conditions
<1%
• Arachnoid cyst Arachnoid cells
• Degenerative cysts (pineal cysts) Glial cells
• Cysticercosis Parasites
• Arteriovenous malformations Vascularization
• Cavernomas
Aneurysms of the vein of Galen
5. Metastases Absence of blood-brain barrier <0.1%
• Lung (most common), breast, stomach, kidney, melanoma
10. Superior colliculus:
Perinaud (50-75%): Paralysis of upgaze: Medial rectus and inferior oblique.
Convergence or retraction nystagmus (60-70%): Co-contraction of all the horizontal extraocular muscles occurs, and the eyes are pulled into
the orbit.
Light near pupillary dissociation (Argyll Robertson's pupil): Accommodate but react.
Midbrain: Sylvian aqueduct syndrome: paralysis of downward or horizontal gaze.
Dorsal midbrain: Settling sun sign, lid retraction (Collier’s) (10%) or ptosis.
Sup. Cerebellar peduncle: Cerebellar efferent fibres: Ataxia and dysmetria.
Inferior colliculus: rare: hearing dysfunction
Rarity:
Seeding: Seizure, Radiculomyelopathy, thalamic pain,
Extrapyramidal (ganglia): rare synchronous lesion.
Compressive symptoms
11. A midline lesion of the posterior
commissure, interrupts most projections
from both Pretectal olivary nucleus (PON),
causing bilateral symmetric loss of the
PLR with preservation of the near response
(bilateral light-near dissociation [LND]).
It is suspected that the near-reflex fibers
approach the Edinger-Westphal nucleus
through the ventral region, unlike the
afferent retinal light-reflex fibers that
follow a dorsal route.
Retinal light-reflex fibers that enter the
Edinger-Westphal nucleus dorsally in the
rostral midbrain are is interfered in the
periaqueductal region, which causes semi
dilated fixed pupil. Coupled with loss of
upward gaze, it manifest as Perinaud’s
syndrome.
Note Argyll Roberson pupil has damage in
peri aqueductal area and manifest
similarly.
Mechanism of light near
pupillary dissociation
12. Endocrine: 10%
Secondary effect of HCP.
Hypothalamic involvement: DI.
Precocious puberty: only boys: Gonadotropin independent Precocious Puberty: Choriocarcinoma or
germinoma containing syncytiotrophoblastic cells: B-HCG subunit is similar to LH: LH stimulate
leydig cells of testes to produce testosterone.
Endocrine symptoms
GIPP: gonadotrophin-independent precocious puberty
13. Germ cell tumors derive from pluripotential germ cells and span a wide range of
differentiation and malignant characteristics.
Most germ cell tumors of the CNS occur in the first three decades (98%) with a peak in the
second decade (65%) between 11 and 20 years.
Intracranial germ cell tumors (GCTs) usually arise in midline structures, including the pineal
or suprasellar regions of children and young adults.
Only germinoma and teratoma are likely to be encountered as pure tumor types.
Intracranial germinomas have been reportedly associated with genetic diseases, including
Klinefelter syndrome, Down syndrome , Retinoblastoma (RB1 gene) and neurofibromatosis
type 1 (Merlin).
GERM CELL TUMOR
14. The multiple histologic subtypes of GCTs are presumed to share a common cell of origin.
Teilum’s “germ cell theory” proposes that extragonadal GCTs arise from primordial germ
cells that have migrated aberrantly during embryonic development and then undergo
malignant transformation.
An alternative theory is the “embryonic cell theory,” which suggests that a mis-migrational
pluripotent embryonic cell gives rise to GCTs.
Sano and colleagues suggested that pure germinomas are the only tumors that truly arise from
germ cells, and other GCTs develop secondary to misfolding and misplacement of embryonic
cells into the lateral mesoderm causing these cells to become entrapped in different brain
regions.
Gonadotropins play a role in the development or progression of CNS germ cell tumors.
Klinefelter syndrome,: elevated gonadotropinsGCT.
Teilum regarded embryonal carcinomas as tumors of totipotential cells that may give rise to
either embryonal neoplasms, with the potential to differentiate into the derivatives of all three
germ layers (teratoma), or extraembryonal neoplasms (yolk sac tumor and choriocarcinoma).
Theory of GCT development
Maria E et a. Pediatric Central Nervous System Germ Cell Tumors: A Review. The oncologist. 2008
15. Teilum’s “germ cell theory
Common cell of origin.
Teilum’s “germ cell theory” proposes that extragonadal gcts arise from primordial germ cells that have migrated aberrantly
during embryonic development and then undergo malignant transformation.
16. Studies: Gonadotropins play a role in the development or progression of CNS germ cell
tumors.
Klinefelter syndrome,: elevated gonadotropinsGCT.
Gonadotropin in GCT
17. Germinomas are the most common GCTs in the neuraxis:
Pineal and suprasellar (neurohypophyseal) regions.
Germinoma are the most radiosensitive malignant tumor in the CNS.
Typical germinomas contain two cell populations (two-cell pattern).
One cell population contains large neoplastic tumor cells with
prominent nucleoli, and the other consists of lymphocytes.
Necrosis and hemorrhage are usually absent.
Germinoma
18. Cell membrane labeling for the proto-oncogene c-kit is also characteristic of germinomas and
not shared by other GCTs.
90% long term control rate for these tumors.
Germinoma with elevated B-HCG level have a less favourable outcome: Benefited with
aggressive treatment of chemotherapy+Radiation.
5 year survival: 75%; 10 year survival: 69% with 5000cGy.
Adverse outcome of XRT: Cognitive deficit, hypothalamic and endocrine dysfunction,
cerebral necrosis, secondary glioma.
Intraventriculuar plaques are histopathologically identical to the primary germinomas.
Treatment of germinomas radiation volume should involve the whole ventricular system
including obex of the fourth ventricle and pituitary fossa.
With complete diagnostic craniospinal evaluation, spinal irradiation is not necessary and the
cure rates for localized germinomas are excellent with extended focal irradiation including
the third and lateral ventricles as well as the sella and the pineal region (whole ventricular
field)
19. Previously, this cytological pattern was considered to be almost pathognomonic, but later, it
was realized that other diseases can also show similar cytological patterns.
Thus, CNS germinoma cannot be diagnosed by the CSF cytological findings alone, although
it may be helpful in establishing the clinical diagnosis.
20. Teratomas differentiate along ectodermal, endodermal and mesodermal
lines.
These tumors in the pineal region most often affect males.
They are usually identified within the first two decades of life but occur
more often in much younger children than other germ cell tumors
3 subtypes
Mature teratomas contain 3 well-differentiated germ cell layers: ectoderm,
endoderm and mesoderm layer: prognosis good.
aggregates of keratin debris, fat, cartilage and bone
Immature teratomas are composed of incompletely differentiated tissues
resembling fatal tissue, most frequently associated with malignant course.
Immature teratomas are the most common type of teratomas arising from
the CNS.
Teratomas that, like carcinomas and sarcomas, contain elements exhibiting
unequivocal malignant transformation are referred to as teratomas with
malignant transformation.
Teratoma
21. Yolk sac tumors are highly malignant GCTs mimicking normal yolk sac structures.
About half of primary intracranial yolk sac tumors are mixed GCTs containing various
proportions of other germ cell elements.
Marker: An elevated level of AFP alone in blood and/or CSF is strongly suggestive of yolk
sac tumor.
Macroscopy
The tumors are firm in consistency and contain gelatinous or myxomatous areas.
Hemorrhagic and necrotic areas are frequently seen.
Microscopy:
Schiller-Duval bodies and Eosinophilic hyaline globules are diagnostic.
Yolk sac tumor
22. Intracranial embryonal carcinomas are rare variants of GCTs.
Tumor cells may exceptionally replicate the structure of an early embryo,
forming ‘embryoid bodies’, which include germ discs and miniature
amniotic cavities.
Embryonal carcinomas often differentiate into yolk sac tumor and
choriocarcinoma, accompanied by elevation of serum AFP and β-HCG
levels.
Embryonal carcinomas contain primitive epithelial cells growing in solid
sheets or poorly formed glands with necrosis.
DIsseminate via the CSF spontaneously, or iatrogenically (shunting)
Spinal axis evaluation and CSF analysis.
Prophylactic craniospinal XRT is indicated following surgical removal, but
cranial XRT is avoided if at all possible before 3 years of age to avoid
intellectual impairment and growth retardation.
Collin’s law: AKA period of risk of recurrence (PRR)
PRR = the age at diagnosis plus 9 months.
Embryonal carcinoma
23. Choriocarcinomas are extremely rare forms of intracranial GCTs.
Pure: rare; Mixed
Two characteristic cell types: Cytotrophoblastic cells and syncytiotrophoblastic.
Cytotrophoblastic cells are round to polygonal with clear cytoplasm, round nuclei and
prominent nucleoli.
syncytiotrophoblastic typically contain pleomorphic densely hyperchromatic multiple
nuclei, and frequently show mitotic figures.
Extensive hemorrhage and necrosis are diagnostic.
These tumors are highly malignant and usually invade adjacent structures.
Metastasis, especially in the lungs.
Choriocarcinoma
25. Pineocytomas are well-differentiated bening neoplasm composed of
relatively small, uniform, mature cells resembling mature pineocytes.
Young adult.
Degenerative changes including cyst formation and focal hemorrhage
can be present.
They may disseminate widely along the CSF pathways.
There is no evidence of local infiltration into adjacent brain parenchyma
and leptomeninges.
IHC: synaptophysin, neurofilaments, class III β-tubulin, and
chromogranin A ,
Interstitial cells are usually positive for GFAP and S-100 protein.
PINEALOCYTOMA
26. Highly malignant (WHO IV) primitive embryonal tumor of the pineal
gland and represents a true primitive neuroectodermal tumor (PNET).
Young age.
Hemorrhage and/or necrosis are common, and craniospinal
dissemination through the CSF occurs frequently.
Extracranial metastatic spread of the tumor may occur to the peritoneal
cavity via the ventriculoperitoneal shunt.
Extremely rare extracranial metastases to the bone or lung.
Pineal anlage tumors.
Hypercellular and closely packed patternless sheets of small cells,
mimicking primitive neuroectodermal tumor or medulloblastoma.
Numerous Homer Wright rosettes and occasional Flexner-Wintersteiner
rosettes are observed.
IHC: synaptophysin, neurofilaments, class III β-tubulin, chromogranin
A, and retinal S-antigen
Pinealoblastoma
27. This rather newly defined group consists of rare neuroepithelial tumors in adults
characterized by a typical papillary structure and epithelial structure.
Their biological behavior is variable and shows a similar course to the one of grade II or III
tumors.
The origin of that group of tumors is specialized ependymal cells from the subcommissural
region.
The incidence seems extremely rare; no more than 100 cases.
Tumor progression occurred in more than 70%.
Papillary tumor
28. The absence of a blood-brain barrier
Lung, Breast, stomach, kidney, and melanomas.
METASTASES TO THE PINEAL REGION
30. Age group Most common Less common
Infant Pinealoblastoma Arachnoid cyst
V of Galen Malf
Childhood Germinoma
Glioma
Tuberculoma
Pinealoblastoma
Pineal cyst
Young adult NGGCT
Glioma
Pinealoblastoma
Pineal cyst
Older adult Pinealocytoma
Glioma
Meningioma
Epidermoid
Mets
Pineal mass with Age
31.
32. Hydrocephalus
Size
Synchronous lesion:
Sellar and pineal: 10%, Occurrence : Basal ganglia.
Trilateral retinoblastoma syndrome: Pinealoblastoma in RB1gene abnormality patients.
Pineal calcification: 60% above 20yrs, rare below 6yrs, Size >1cm high suspicion.
Extent: Lateral or supratentorial extension.
Anatomical relationship
Involvement of 3rd ventricle
Involvement of brainstem
Vascularity: Location of deep venous system and its relation to the tumor.
Germinoma: Displaces it superiorly along the dorsal periphery of tumor: SCITapproach
(Krause)
Meningioma (velum interpositum), Epidermoid, C. Callosum tumor: displaces it ventrally and
inferiorly. Supratentorial approach: OTT (Poppen)
Spinal seeding
IMAGING
35. ICH PROFILE (TUMOR MARKERS) OF TUMOR OF PINEAL REGION
Type
(Normal value)
Alpha
Fetoprotein
(<5ng/mL)
Human
Chorionic
Gonadotropin
(<5mIU/mL)
Human
Placental
Lactogen
HPL
Placental
Alkaline
Phosphatase
PLAP
Cytokeratins
(CAM 5.2, AE 1/3)
c-kit
(CD 117)
OCT 4 Melatonin
Germinoma – + <770ng/mL – ++ – + + –
Teratoma
+
(<1000ng/m
L)
– – – + +/- – –
Yolk sac tumor +++ – – +/- + – – –
Embryonal
carcinoma
++
(<1000ng/m
L)
++
(<770ng/mL)
– + + – + –
Choriocarci-
noma
–
+++
(>2000ng/mL)
++ +/- + – – –
Pinealocytoma – – – – – – – +
Pinealo- blastoma – – – – – – – ++
Papillary tumor – – – – ++ – – –
CSF tends to be more sensitive than serum levels.
PLAP is detected in cytoplasmic staining in Germinoma.
A-FP: Fetal yolk sac element: B-HCG: Trophoblastic product;
Although the presence of germ cell markers indicate a malignant germ cell tumor, the converse is not necessarily true.
Absence of marker should be interpreted cautiously.
If A-FP is present in Germinoma; think of mixed tumor. (Youman)
A TYE; Before ECG; HPL: Cardio, PG Ellenbogen 3rd ed
TUMOR MARKERS
36. 1. Tissue diagnosis and treatment:
2. Pinealocytoma: surgery may be curative
3. Pinealoblastoma: No evidence surgery improves the outcome.
4. Choice of post op adjuvant therapy:
i. Radiation: Malignant germ cell tumor, Germinoma
ii. Chemotherapy: NG-GCT, Germinoma with synctiotrophoblastic with elevated B-HCG.
iii. Teratoma: Doesnot responds to Chemo or radiotherapy: Surgery is indicated.
5. Metastatic work up: High: Germinoma, Choriocarcinoma, pinealoblastoma; None: Pinealocytoma,
Variable: Glioma, Teratoma.
6. Estimation of Prognosis:
i. Good prognosis: Germinoma, Mature teratoma, Pinealocytoma
ii. Intermediate prognosis: Germinoma with elevated levels of B-HCG, Immature teratoma,
Extensive/multifocal/germinoma, Teratoma with malignant transformation, Mixed tumors
composed mainly of germinoma or teratoma.
iii. Poor prognosis: Choriocarcinoma, Yolk sac tumor , Embryonal carcinoma, Pinealoblastoma,
Mixed tumors composed mainly of choriocarcinoma, yolk sac tumor, or embryonal carcinoma.
7. Planning of long term follow up:
Histology is must
38. 1. Location of tumor (Tentorial incisura)
2. Tumor morphology (lateral extent)
3. Displacement of great veins
4. Probable diagnosis on imaging
5. Angle of tentorium/ posterior fossa size
6. Surgeons preference
CHOICE OF APPROACH
39. 1. The posterior transcallosal approach : Dandy.
2. The trans-ventricular approach : VanWagenen.
3. The occipital transtentorial approach : Foerster and Poppen.
4. The infratentorial-supracerebellar approach : Krause (Stein).
5. Three-quarter prone, operated side down, OTT : Ausman.
Common surgical approach
40. Preoperative evaluation of leptomeningeal dissemination is essential for selecting appropriate
postoperative adjuvant therapies and for predicting the prognosis of the patients.
Whole neuraxis magnetic resonance imaging and cytological examination of the
cerebrospinal fluid should be undertaken depending on whether the patient’s condition
permits it.
Tumor markers including human chorionic gonadotropin β-subunit, α- fetoprotein, and
placental alkaline phosphatase in the serum or cerebrospinal fluid are assayed
Neuroophthalmological evaluation is useful for detecting Parinaud’s syndrome and
papilloedema
Obstructive hydrocephalus with increased intracranial pressure
Administration of corticosteroids.
Ventricular drainage is instituted before or during the craniotomy.
Shunt operations should be avoided:
Hydrocephalus generally improves after tumor resection
Peritoneal dissemination of the tumor cells via the shunting system.
Pre-operative management
41. • Hydrocephalus
• EVD
• Shunt
• ETV
• Tissue diagnosis
• ETV + biopsy
• Stereotacatic biopsy
• Open surgery
• Tumor control
• Surgery
• Radiotherapy
• Chemotherapy
Management
• Microsurgical excision is still nowadays the mainstay of
management for most pineal region tumors.
• An exception is germ cell tumors in which treatment
policies include radiotherapy and chemotherapy after
obtaining a biopsy, radiotherapy and chemotherapy
without biopsy,
• Endoscopic tumor biopsy with simultaneous endoscopic
third ventriculostomy (ETV) has emerged as a
minimally invasive and highly effective strategy for
initial management since it addresses the issue of tissue
diagnosis and offers a solution for the associated
hydrocephalus.
42. • Present in almost all cases
• Must be addressed prior to tumor surgery
• Stable patient, complete resection likely, temporary EVD at time of surgery
• Symptomatic raised ICP
• ETV +/-‐ biopsy
» Gradual reduction of ICP
» Avoids peritoneal seeding
» Avoids shunt related complications
• VP shunt: Risk of metastasis.
Hydrocephalus
43. SURGICALANATOMY
• Most arise from or attached to undersurface of velum interpositum, rarely
extends above
• Blood supply comes from within velum mainly from M P.ch & L P.ch with anastomoses to
pericallosal & quadrigeminal artery
• Most tumors are centered at pineal gland, some extend to Foramen of Monroe
44. SURGICALANATOMY
• Mostly ICV, Galen , Rosenthal & precentral cerebellar veins surround or cap the periphery of these
tumors.
• Rarely, ICV are ventral to tumor.
• Highly vascular tumors
– Pineoblastomas
– Hemangioblastomas
– Hemangiopericytomas
46. • Infratentorial supracerebellar:
• Approach to center of tumor
• Minimizes risk to veins
• Good exposure
• No violation of normal tissue
• Occipital transtentorial / Transcallosal interhemispheric
• Tumors extending superiorly
• Extending laterally
• Displaces veins ventrally
• Large tumors
• Greater exposure
Surgery common approaches
47. Infratentorial supracerebellar approach
• Position
• Sitting preferred
– Can also be done in Concorde position
• Large ventricle/ <3 years – 3 quarter prone
• Table should be able to go low
• Head flexed to keep tentorium parallel to floor
• Patient tilted forward
49. INFRATENTORIAL SUPRACEREBELLAR APPROACH
• Exposure
• Incision – inion to C4, spinous process of C2 exposed
• Burrhole – above torcula, lateral aspect of transverse sinus
• Craniotomy – exposing transverse sinus and torcula
• If dura tense release CSF (ventricular tap)
50. Dural incision – curved between lateral most
aspect of transverse sinus
Dura retracted
Avoid excess retraction – sinus occlusion
SUPRACEREBELLAR INFRATENTORIAL APPROACH
51.
52. INFRATENTORIAL SUPRACEREBELLAR APPROACH
• Surgical technique
– Cauterize and divide adhesions and veins
between cerebellum and tentorium.
– Retract vermis poster inferiorly.
– Open arachnoid over the tumor
(opaque white),
– The precentral cerebellar vein and the
superior vermian vein are identified
and in most cases cut before the tumor
is dissected.
– Small branches of choroidal and SCA over tumor
divided.
– Trajectory of dissection changed towards the
tumor.
Precentral cerebellar vein in the center of the
field. This vein can be sacrificed to gain direct
access the pineal gland and lesion
53. Internal debulking of tumor
Lateral walls dissected, vessels on it are choroidal and may be sacrificed
Dissection of inferior tumor from brainstem
Most dangerous parts
Assistant retracts capsule upwards
Final dissection – superior along velum interpositum, great veins at risk
55. Advantage
• Dissection proceed without transgressing
the galenic system.
• Gravity aided drainage of blood/ CSF:
less pooling of blood in field.
• Gravity aided cerebellar retraction
• Midline – orientation easy
• Strictly midline trajectory through which
disorientation is less likely. (C.F OTT)
• No neural structures en route
INFRATENTORIAL SUPRACEREBELLAR
Disadvantage
• Air embolism
• Surgeon fatigue
• A narrow angle to the lateral and caudal side
of the surgical field.
• Difficult in very young and old.
• No ideal in steep inclination of tentorium.
• Quadriplegia from excessive flexion in
elderly
• Hypotension
56. • POSITION
– On the side: usually right side down
– Upper part of trunk raised 30`
– Head flexed with neck stretched
– & rotated 45` face down
• SURGICAL TECHNIQUE
– S-shaped incision behind mastoid
– Oval craniectomy close to sigmoid sinus laterally & transverse sinus superiorly
– Durotomy : cruciate
– Bridging veins divided, petrosal & precentral cerebellar veins preserved.
– Tentorial incisura reached, preserving SCA.
LATERAL PARAMEDIAN INFRATENTORIAL
57. • INDICATIONS
• Biopsy
• Small quadrigeminal area tumor
• ADVANTAGE
• Minimal damage to neural tissues
• Useful in steep tentorium
• Reduced risk of air embolism (lateral position)
• DISADVANTAGES
• Narrow space
• Difficult to reach tumor portion extending to infero posterior part of 3rd ventricle
LATERAL PARAMEDIAN INFRATENTORIAL
58. • Commonest supratentorial approach
• Indications
– Predominantly supratentorial
– Corpus callosum extension
– Lateral extension into cerebral hemisphere
– Thalamic extension
– Predominantly third ventricular mass.
• Advantage
– Extensive tumor view.
– Managing bleeding is easier.
– Working distance is smaller
– Access to pineal, third ventricle, midbrain, superior vermis
• Disadvantages
– View obstructed by Galenic venous system
– Restricted view of opposite side
– Oblique trajectory, which may at times be disorienting for surgeons not
familiar with the approach
OCCIPITALTRANSTENTORIALAPPROACH
59. • Position
– Lateral decubitus with
• Rt side down.
• Midsagittal plane 30’ above horizontal
– Three quarter prone
– Prone
– Sitting
Occipital transtentorial approach
60. • Craniotomy
– Incision: U SHAPE (6-10cm flap)
– Craniotomy : 6 burr holes
– 2 on left, 2 on right of sagittal Sinus
– 1 just rostral to transverse sinus
– 1 parietal.
– Durotomy: Reflected along sagittal sinus with “T” incision.
– Retractor on inferior surface of occipital lobe.
Exposure
61. 1. Occipital retraction to be kept minimum.
2. CSF release (from posterior callosal/ dorsal mesencephalic cisterns)
3. Opening of arachnoid (venous system lies in it)
4. Yasargil – positively identify vein of Rosenthal- Galen junction
(Vein of Rosenthal may be mistaken for darkly colored dorsal mesencephalic cistern)
5. Tentorium incised 5 – 10 mm from the midline to avoid the superior cerebellar veins, which join the straight
sinus from a paramedian position.
SURGICAL STEPS
6. Medial flap sutured to falx.
7. Identify and preserve IV nerve when manipulating tent.
8. Precentral cerebellar vein may be sacrificed.
9. Tentorial splitting*: Inferior sagital sinus and falx may be divided to
facilitate further falcial retraction.
10. At this point, arachnoid overlying the tumor and quadrigeminal
plate may be seen.
11. Resection:
• Cleavage plane found in small tumor.
• Debulking in large tumor.
• For hypervascular tumor: feeding arteries identified &
coagulated prior to debulking .
• To avoid venous injury, total resection is not necessary &
should not be attempted.
12. Immaculate hemostasis, water-‐tight dura closure.
Occipital lobe retraction was greatly
reduced as the occipital lobe
sufficiently fell away from the
operative field and required minimal
retraction.
Significantly decrease the incidence
of postoperative visual field defects
Splitting the tentorium offers a
panoramic supra‐ and
infratentorial view of the tumor,
the surrounding deep venous
structures and the collicular plate
of the midbrain.
62. INDICATIONS
• Predominantly supratentorial tumor
• Position
• Sitting/ prone
• Lateral / 3 quarter prone.
TRANSCALLOSAL INTERHEMISPHERIC
SURGERY
– U shapes skin flap across the midline
– Bone flap across the midline
– Position of bone flap depending on centering of the
tumor
– Wide craniotomy for alternate corridors to avoid
bridging veins
– Avoid sacrifice of more than 1 bridging vein
– Pericallosal retracted
– Callosotomy <2 cm centered over the tumor bulge.
– Identify deep veins early.
63.
64. • Indication
– Tumor extending into lateral ventricle
• Disadvantage
• Limited exposure
• Cortical incision required
• Stereotactic guidance may be required
TRANSCORTICAL TRANSVETRICULAR
69. Hemiparesis – Brain retraction – Sacrifice of bridging veins
Sensory stereognostic deficits – Parietal lobe retraction injury
Visual field defects – Occipital lobe retraction injury
Disconnection syndrome – Corpus callosum section
Memory defecits – Fornix injury
Bleed in residual tumor
Thrombosis of the basal veins of Rosenthal and internal cerebral veins: Fatal
hemorrhagic infarction: Vein should be coagulated as far as possible from the confluence of
the basal veins of Rosenthal.
COMPLICATIONS OF SUPRATENTORIAL APPROACH
70. Biopsy failure of a mixed GCT is not rare.
If a mixed GCT is mistakenly interpreted as ‘pure germinoma’ after an initial biopsy, at least
the germinoma component can be eradicated by adjuvant therapy, and other components may
remain.
After that, a second-look surgery is feasible to resect the residual tumor that was resistant to
the adjuvant therapy.
When the level of HCG is normalized, the residual mass is almost always a teratoma
Emphasis must be placed on performing an extremely careful histological examination in
which the entire part of the resected specimen is searched.
Biopsy failure of a mixed GCT
71. Indications:
Non germinomatous malignant germ cell tumors
Germinoma with syncytiotrophoblastic giant cells
Recurrent /disseminated pineal cell tumors
Regimens:
Testicular cancer protocal: Einhorn regimen: Cisplatin, Vinblastine, bleomycin.
Cisplatin/carboplatin + Etoposide – Widely used.
Others: Vincristine/lomustine/cyclophosphamide.
Success with various regimen been limited, so no clear cut recommendation.
Platinum-based chemotherapy yielded a complete response (CR) rate of 85–100% in patients with germinomas.
This has led to the speculation that chemotherapy may eventually replace radiotherapy
Germinomas tend to be treated with a lower dose of irradiation than those used with conventional radiotherapy of 40–55 Gy.
Pre-irradiation chemotherapy has been advocated as an adjuvant therapy to further decrease the total volume of
radiation therapy.
The combined chemoradiotherapy approach has afforded the ability to decrease the dose and volume of radiation
therapy without affecting survival rates and with minimal endocrinopathy and minimal neurocognitive dysfunction
ADJUVANT CHEMOTHERAPY
Maria E et a. Pediatric Central Nervous System Germ Cell Tumors: A Review. The oncologist. 2008
72. It has been a matter of controversy whether the partially removed mature teratoma should be
treated with adjuvant therapy or simply observed until relapse.
Even if histological diagnosis of the resected specimen is mature teratoma, the residual
part may contain a small portion of immature or other malignant tissue.
A true mature teratoma is resistant to chemoradiation therapy and eventually grows
during the adjuvant therapy.
Immature teratomas require adjuvant therapy because they often recur even after a gross
total resection.
73. Non-germinomas into two groups, intermediate prognosis (moderate malignancy), and poor
prognosis (high malignancy) groups
74. Primary: Germinoma
Radiation therapy (RT) plays a primary role in the treatment of germinomas and a 90–100% curative rate can be
expected after RT alone.
Patients with these B-HCG– secreting GCT appear to have inferior outcomes with the use of irradiation alone.
The recommended radiation dose is 55 Gy given in 1.8 Gy daily fractions, with 40 cGy to the ventricular system and an
additional 15 cGy to the tumor bed.
Pinealoblastoma (55 Gy to bed, 35 Gy to spinal axis)
Pinealocytoma (No effect on survival in incompletely excised tumors)
All malignant germ cell/ pineal cell neoplasm – can be with held for histologically benign completely resected
pinealocytoma, ependymoma.
CSI is not necessary for localized germinomas.
Dose reductions to the primary site have maintained cure rates >90%.
Patterns of relapse following CSI versus reduced volume radiation, either with whole-brain or whole- ventricular radiation
therapy are not significantly different.
Treatment with whole-ventricular irradiation does not result in a greater number of relapses than with CSI.
Radiation therapy remains a vital accepted treatment strategy in CNS NGGCTs; however, controversy still exists over the
necessity of CSI versus focal or whole- ventricular radiotherapy, especially in patients with localized disease.
On the other hand, nongerminomatous GCTs (NGGCTs) are generally aggressive and most patients with non-
germinomatous tumors treated conventionally with surgery and RT fail to survive longer than 3 years
RADIOTHERAPY
76. Indications
Invasive disseminated tumor at diagnosis
Multiple medical problems
Selected cases with very large tumors
Neonate with large tumor (highly malignant, poor prognosis)
Presentation suggestive of infectious/ metastatic disease with diffuse systemic disease
Target selection – Avidly enhancing tumor, preferably from the centre – Multiple sites
STEREOTACTIC BIOPSY
77. Orthogonal lateral
Traverses the temporalis muscle
Technically difficult using a stereotactic frame
Oblique anterolateral:
Most preferred
Low frontal trajectory below the plane of the internal cerebral veins.
Anterior to the coronal suture and lateral to the midpupillary line is usually preferred.
Often a point just behind the hairline, at the superior temporal line.
Trajectory traverses the frontal lobe and internal capsule, staying lateral to the lateral
ventricle
Posterolateral superior approach:
Entry point at the parietooccipital junction
Lesions with significant lateral extension
TRAJECTORIES
Oblique anterolateral:
78. Histologically confirmed
Maximum experience with pinealocytoma.
Used as an adjuvant therapy.
Possibly primary therapy for pinealocytoma
Indications still evolving –
Current possible indications
1. Pineal parenchymal tumors
2. Germinoma
3. NGGCT
4. Astrocytoma
GKRS
79. High-dose chemotherapy with autologous hematopoietic cell rescue (AuHCR) has
traditionally been reserved for patients with refractory or recurrent GCTs; however, this
approach has also shown promise as consolidation therapy for some high-risk gonadal GCTs
at diagnosis
AUTOLOGOUS HEMATOPOIETIC CELL RESCUE (AUHCR)
80. Overall Survival
Five-year survival rates
>90% Germinoma : using irradiation alone
>70% Mixed germinoma, teratoma, immature teratoma with malignant elements or
mixed tumors that predominantly consisted of germinomas or teratomas
67% NGGCT patients
Treated with two cycles of chemotherapy followed by surgical resection, 36 Gy
of CSI, and 14 Gy to the tumor bed followed by two further courses of
chemotherapy.
9.3% Choriocarcinoma, endodermal sinus tumor, or embryonal carcinoma
81. Pineal region surgery is certainly not trivial, but within the last 25 years major morbidity and
mortality (50%) from published surgical series have improved dramatically and have dropped
to 0 to 2% in published surgical series.
Significant improvement in outcome
Mortality: 50% 0-2%*
Improved neuroimaging, Microneurosurgery, Neurointensive and anaesthesia care.
Mortality
• Regis J et al. Retrospective study: Pineal region tumors and the role of stereotactic biopsy: review of the mortality,
morbidity, and diagnostic rates in 370 cases. Neurosurgery. 1996.
• Bruce J. Youman’s Neurological Surgery: Pineal Tumors. Philadelphia: WB Saunders, 2011:1011–1029
82. 1. Gross total resections, however, are not currently recommended because of the risk for
postsurgical morbidity.
2. The value of partial or gross total resections in germinomas has not been proven, and the role
of radical resection in NGGCTs is still unclear.
3. For patients with mature teratomas, however, gross total resection of the tumor is usually
curative.
BOTTOM LINE
83. References:
Ellenbogen Principle of Neurological surgery 4th edition
Greenberg Handbook of Neurosurgery; 8th edition
Youman’s Winn Neurological surgery; 7th edition
Schmidek and Sweet operative Neurosugical technique 5th edition
Pineal region tumor editor. Lunsford, Vol 23, 2009
Maria E et a. Pediatric Central Nervous System Germ Cell Tumors: A Review. The oncologist. 2008
PINEAL NEOPLASM
TAKE HOME MESSAGE
1. Pineal gland lies in Geometric center of brain in dienchephalic roof at the posterior extremity to 3rd
ventricle
2. Pineal tumor are rare: 0.4 to 1.0 % (adults) and 3-8 % in children.
3. Teilum’s germ cell theory proposes that extragonadal GCTs arise from primordial germ cells that
have migrated aberrantly during embryonic development and then undergo malignant
transformation.
4. Association of GCT with Klienfelter syndrome has unfolded the role of gonadotropin.
5. Pineal calcification of size >1cm: high suspicion.
6. Center calcification is rare presentation of germinoma while blasted calcification of
Pinealoblastoma.
7. Pure tumor are only Germinoma and Mature teratoma. Rest are mostly mixed.
8. AFP and B-HCG help to differentiate germinomas from NGGCTs. If AFP and B-HCG is present
in Germinoma; think of mixed tumor.
9. Elevated serum or CSF concentrations of AFP and B-HCG are strong predictors of NGGCTs.
10. Although the presence of germ cell markers indicate a malignant germ cell tumor, the converse is
not necessarily true.
11. Invasive nature is seen with Germinoma and pinealoblastoma.