This document provides an overview of the pineal gland and pineal region tumors. It begins with the anatomy and histology of the pineal gland, then discusses common tumor types including germinomas, teratomas, pineocytomas, pineoblastomas, and others. For each tumor type, the characteristics, imaging appearance, histology, and clinical features are described. The document also reviews the surgical anatomy of the pineal region and historical aspects of pineal tumor surgery. Overall, it serves as a comprehensive reference for the pineal gland and tumors that originate within this region.

1. INTRODUCTION
 Pineal gland :- Epiphysis Cerebri.
 Pine cone shaped gland of the
endocrine system.(Vesalius)
 The gland is a conical, grey body, with 5-8 X 3-5mm
 A structure of the diencephalon of the brain, produces
several important hormones including melatonin.

2.  Melatonin:- sexual development and
sleep-wake cycles.
 Pineal Gland is midline structure located in the
epithalamus, near the centre of the brain, between
the two hemispheres, in a groove where the two
halves of the thalamus join.

3. HISTOLOGICAL ORGANIZATION
 Pia Mater Surrounds the pineal body.
 which functions as its capsule and which sends
connective tissue septa into the pineal body,
subdividing it into lobules.
 Two cell types:
1. Pinealocytes (about 95% of the cells; large, light and
round nuclei)
2. Astrocytes (glial cells; dark, elongated nuclei).

4. CORPORA ARENACEA
 Aside from the cells the pineal gland also contains
brain sand (corpora arenacea).
 These are calcium-containing concretions in the pineal
parenchyma, which increase in size and number with age.
 These concretions are radioopaque, and, since the pineal is
located in the midline of the brain, they provide a good
midline marker.
 They have no other known function.

5.  Pineal calcification:
seen in
approximately 40%
of normal people by
the age of 20 years
and usually less than
1 cm in diameter.
 Larger calcifications
should raise concerns
for underlying
tumor.

6. SURGICAL ANATOMY
 Encapsulated structure (Pia matter)
 Extra-axial structure
 Hence, essentially differentiated from adjacent
structures

7. Pineal region is defined as the area of brain bordered
Dorsally by splenium of corpus callosum and tella choroidea,
Ventrally by Quadrigeminal plate and midbrain tectum,
Rostrally by post. Part of 3rd ventricle and
Caudally by the cerebellar vermis

8. PINEAL GLAND RELATIONS
 Ventrally- posterior commissure
 Superiorly – corpus callosum,
 dorsally - habenular commissure

9.  The velum interpositum, which incorporates the internal cerebral veins
and the choroid plexus, is intimate with the dorsal gland.
 The basal veins of Rosenthal combine with the internal cerebral veins
to form the vein of Galen before draining into the straight sinus.

10. The blood supply to the pineal gland is from branches of the medial and lateral
choroidal arteries through anastomoses to the pericallosal, posterior cerebral,
superior cerebellar, and quadrigeminal arteries.

11.  Most pineal masses originate infratentorially and
expand into the posterior third ventricle.
 Further progression can proceed into the thalamus or
posteriorly over the dorsal surface of the quadrigeminal
plate.
 Malignant tumors, particularly of glial origin, can invade
into the midbrain and thalamus, which ultimately
determines the tumor’s resectability.

12. HISTORY OF PINEAL TUMORS AND
SURGERY
1913. Oppenheim and
Krause
the first successful removal of a tumor from the
pineal region
1923. Dandy Described transcallosal approach
1923 Krabbe Term ‘pinealoma’ was originally used for
pineal parenchymal tumors.
1926 Krause Reported infratentorial approach
1928. Foerster Proposed occipital transtentorial approach
1966 Poppen Described in detail occipital transtentorial
approach
1971 Stein modified of Krause’s infratentorial approach

13. PINEAL TUMORS TYPES
1 Germ cell tumors
2 Papillary tumour of pineal region
3 Pineal parenchymal cell tumors
4 Glial cell tumors
5 Miscellaneous tumors and cysts.

14.  • Pineal parenchymal tumor
» Pinealocytoma
» Pinealoblastoma
» Pineal parenchymal tumor of intermediate differentiation
» Papillary tumor of pineal region
 • Germ cell tumors
» Germinoma
» Non germinomatous germ cell tumor
• Embryonal carcinoma
• Yolk sac tumor (endodermal sinus tumor)
• Choriocarcinoma
• Teratoma (mature, immature, malignant)
• Mixed germ cell tumor
 • Glial cell tumors
» Astrocytoma
» Oligodendroglioma
» Ependymoma
» Choroid plexus papilloma
» Anaplastic astrocytoma/ GBM

15.  • Mesenchymal cell tumors
» Meningioma
» Cavernoma/ haemangioblastoma
 • Other tumors
» Epidermoid
» Craniopharyngioma
» Ganglioglioma
» Lipoma
 • Metastasis
 • Lymphoma
 • Non neoplastic mass
» Pineal cyst
» Arachnoid cyst
» Cysticercosis
» Tuberculoma
» Sarcoidosis
» Aneurysm of vein of Galen

16. PINEAL MASS WITH AGE

21. Germinoma
 1%–2% of all cranial neoplasms
 90% of patients are less than 20 years
 Central nervous system germinomas
are similar histologically and genetically to dysgerminoma
in the ovary and seminoma in the testis
 50% to 65% - in the pineal region
 25%–35% in suprasellar region.
 Dissemination by CSF and invasion of the adjacent brain
commonly occur, but the prognosis is good (5-year survival
at least 90%) and the lesions are highly responsive to
radiation therapy

22. Germinoma in a 19-year-old man with headaches.
Fig 1 Sagittal postcontrast T1-weighted MR image shows a lesion in the pineal region that homogeneously enhances. Note
the associated mild hydrocephalus.
Fig 2 Diffusion- weighted MR image shows high signal intensity in the lesion, a finding indicative of high cellularity.
Fig 3 Sagittal gadolinium-enhanced T1-weighted MR image shows nodular enhancing masses (arrows) along the cauda
equina, findings consistent with drop metastases.

23. Germinoma in a 15-year-old boy with headaches.
Fig 1 shows clusters of small round blue cells consistent with lymphocytes (arrows) intermixed with the large polygonal
primitive germ cells. The highly cellular lymphocytic component accounts for the increased attenuation seen at CT and the
high signal intensity at diffusion-weighted MR imaging.
Fig 2 Axial nonenhanced CT image shows a hyperattenuating lesion in the pineal region that has engulfed the pineal
calcification (arrow).

24. Teratoma
 Teratomas differentiate along ectodermal(Skin and skin
appendages), endodermal(Respiratory or enteric
epithelium), and mesodermal lines(presence of cartilage,
bone, fat, and smooth and skeletal muscle)
 Three types of teratoma:
1. mature teratoma (fully differentiated tissue),
2. immature teratoma (complex mixture of fetal-type
tissues from all three germ layers and mature tissue
elements), and
3. teratoma with malignant transformation(least common
form and demonstrates malignant degeneration of the
mature tissues. )

25. Teratoma in an 8-year-old boy with a 2-week history of Parinaud syndrome.
Fig 1 Axial T1- weighted MR image shows a lobulated, heterogeneous lesion that contains an area of hyper
intensity (arrow), a finding consistent with fat.
Fig 2 Post contrast MR image shows enhancement of the soft-tissue portions of the lesion.

26. Mature teratoma.
Fig shows multiple tissue types including sebaceous glands (arrow) and hyaline
cartilage (*).

27. Other GCTs
 Choriocarcinoma,
 yolk sac tumors(Schiller-Duval bodies),
 embryonal carcinoma
-rare neoplasms.
-Evaluation of serum oncoproteins assists in making the
appropriate diagnosis.

28. Pineocytoma WHO GR1
 Slow-growing,
 42% of pineal parenchymal neoplasms.
 occur throughout life but predominantly manifest in
adults .
 The 5-year survival is 86%–100%
 No relapses after GTR
 CSF dissemination rarely occurs.

29. Pineocytoma in a 35-year-old man with a history of headache.
postcontrast T1-weighted MR image shows an avidly enhancing mass in the pineal region with
resultant hydrocephalus.

30. Pineocytoma
F shows small, uniform cells that resemble normal pineocytes. Many of these are arranged in
rosettes (arrowheads).

31. Pineal Parenchymal Tumor
of Intermediate Differentiation(PPTID)
 WHO grade II or III neoplasm.
 At least 20% of all pineal parenchymal tumors
 Prevalence is in early adulthood
 The 5-year survival is 39%–74%
 Rarely metastases

32. PPTID in a 39-year-old man with blurry vision. Papilledema was noted at examination.
Fig 1 Axial T2-weighted MR image shows a hyperintense mass involving the pineal region with
resultant hydrocephalus. A cystic region is present posteriorly (arrow).
Fig 2 On an axial postcontrast T1- weighted MR image, the solid portion of the mass enhances
avidly.

33. PPTID
Fig shows diffuse sheets of uniform cells and formation of small rosettes (arrow).
Features are intermediate between those of pineocytoma and those of pineoblastoma.

34. Pineoblastoma WHO GR-IV
 Highly malignant
 32% of pineal parenchymal tumors
 Embryonal tumors described as a PNET of the pineal
gland.
 CSF dissemination commonly occurs and is the most
common cause of death.
 The 5-year survival is 58%

35. Pineoblastoma in a 4-year-old girl with headaches, vomiting, and double vision.
Fig 1 Axial post contrast T1-weighted MR image shows an ill-defined enhancing pineal mass with
resultant hydrocephalus. The region of enhancement extends into the subarachnoid space, and
there is a suggestion of parenchymal involvement.
Fig 2 Photograph of the gross specimen shows nodularity and discoloration along the
leptomeningeal surface, S/O CSF spread.

36. Pineoblastoma in a 4-year-old boy with nausea and vomiting.
Fig 1 Sagittal T2-weighted MR image shows a large mass in the
pineal region with resultant hydrocephalus. The mass is hyper-
intense relative to gray matter.
Fig 2 Postcontrast T1-weighted MR image shows
heterogeneous enhancement within the mass.
Fig 3 Diffusion- weighted image shows hyperintensity within
the lesion. The mass had low signal intensity on the apparent
diffusion coefficient map, a finding indicative of reduced
diffusion and reflective of the highly cellular nature of the
neoplasm.

37. Trilateral retinoblastoma in a 2-year-old girl with a history of enucleation for retinoblastoma.
Fig 1 Axial postcontrast fat-saturated T1-weighted MR image shows a focus of enhancement along
the medial wall of the left globe (arrow), a finding consistent with retinoblastoma. The right globe
was removed due to retinoblastoma, and a prosthesis is in place.
Fig 2 Axial post- contrast T1-weighted MR image shows an associated enhancing pineoblastoma
with resultant hydrocephalus.

38. Papillary Tumor of the Pineal
Region
 Rare neuroepithelial neoplasm
 Occurs in both children and adults,
 Age range of 5–66 years (mean age, 31.5 years)
 Thought to arise from specialized ependymocytes in
the subcommissural organ, which is located in the
pineal region.
 WHO grade II or III

39. PTPR in a 17-year-old girl with headaches, vomiting, and double vision.
Fig 1 Axial T2-weighted MR image shows a small, heterogeneous, cystic and solid lesion in the
pineal region. Hydrocephalus is present.
Fig 2 Postcontrast T1-weighted MR image shows enhancement of the solid portion of the lesion.

40. PTPR.
Fig shows Pseudorosette formation around the vessels (arrows).

41. Astrocytoma
 Uncommon.
 Derive from stromal astrocytes, and in the pineal
region they arise from the splenium of the corpus
callosum, the thalamus, or the tectum of the midbrain.
 Rarely, neuronal elements within the pineal gland.
 Circumscribed (pilocytic, WHO grade I) or diffusely
infiltrating (WHO grades II–IV).

42. Tectal glioma in a 5-year-old girl with headaches and drowsiness.
Fig 1 Sagittal nonenhanced T1- weighted MR image shows enlargement of the tectal plate (arrow) with
resultant compression of the aqueduct. There is marked hydrocephalus involving the lateral and third
ventricles.
Fig 2 Photograph of the gross specimen shows enlargement of the tectal plate (arrow).

43. Meningioma
 Meningiomas are dural based lesions, mainly arising
from tentorium in this region.
 Calcifications are seen in 15%–20%.
 At CT, meningiomas are typically hyperattenuating,
reflecting the highly cellular nature of these lesions.

44. Meningioma in a 42-year-old woman with headaches and visual changes.
Fig 1 Nonenhanced CT image shows a large hyperattenuating lesion with an associated calcification
(arrow) in the pineal region. There is resultant hydrocephalus and transependymal flow of CSF.
Fig 2 Sagittal postcontrast T1-weighted MR image shows a homogeneously enhancing broad-based
lesion attached to the tentorium.

45. Lipoma
 Arise from abnormal differentiation of the meninx
primitiva (the undifferentiated mesenchyme that
surrounds the developing brain and normally develops
into the leptomeninges and subarachnoid space.)
 Lipomas represent malformations and not
neoplasms.
 Blood vessels and nerves course through them, making
resection difficult if required.

46. Lipoma in a 27-year-old woman with headaches, nausea, and vomiting.
Fig 1 Sagittal nonenhanced T1-weighted MR image shows a well-circumscribed, hyperintense lesion in
the quadrigeminal plate cistern.
Fig 2 Photograph of a gross specimen from another patient shows a yellow, fatty mass (arrow) in the
quadri- geminal plate cistern.

47. CLINICAL FEATURES
 Raised ICP due to obstructive HCP:
– Headache
– nausea, vomiting, obtundation, cognitive
impairment, papilledema, and ataxia
 Endocrine dysfunction (secondary effects of
hydrocephalus or hypothalamic spread):
– Diabetes insipidus (germinoma) – develops early
– Precocious puberty: pseudoprecocious puberty

48. DIRECT MIDBRAIN COMPRESSION
 Parinaud’s syndrome(superior colliculus )
paralysis of upgaze
convergence or retraction nystagmus and
pupillary light-near dissociation
 Sylvian aqueduct syndrome
paralysis of down gaze or horizontal gaze
 Dorsal midbrain compression or infiltration
lid retraction (Collier’s sign) or ptosis;
 fourth nerve palsies with diplopia and head tilt
 superior cerebellar peduncles – ataxia and dysmetria
 Inferior colliculi (rare) – hearing dysfunction
 pineal apoplexy from hemorrhage — rare

49. DIAGNOSIS
 MRI: Investigation of choice
– Degree of hydrocephalus
– Tumor size, vascularity, homogeneity
– anatomic relationships with surrounding structures
 planning the approach: Supra-/infratentorial
 Position within the third ventricle, lateral and supra-
tentorial extension, degree of brainstem involvement.
 Extent of invasiveness – margination and irregularities
of the tumor border

50. MRI:–
Tumor histology—germinomas = higher ADC
signal
–
MRV:
– delineate the deep venous system
■
CT:
– calcification, BBB breakdown, vascularity
■
Angiography:
– vascular tumors

52. TUMOR MARKERS
 ■ Alpha-fetoprotein/beta-HCG (CSF/serum):
malignant germ cell elements
– CSF levels more sensitive
– monitoring response to adjuvant therapy or as an
early sign of recurrence
■ Others—in IHC:
– LDH, PLAP
– Melatonin, S antigen — investigational

54. TREATMENT

55. Management of Hydrocephalus
 Symptomatic — stereotactic-guided endoscopic third
ventriculostomy
– eliminates potential complications such as infection,
overshunting, and peritoneal seeding of malignant cells
 Mildly symptomatic, gross total resection anticipated
— ventricular drain placed at the time of surgical
resection
– removed or converted to a shunt in the postoperative
period

56. Tissue diagnosis—biopsy vs open
resection
 Only time that a tissue diagnosis unnecessary—malignant germ
cell markers
 STEREOTACTIC BIOPSY:
– primary systemic tumors,
 multiple lesions,
 medical C/I to open resection
 radiographic evidence of brainstem
– Adv.— ease of procedure, LA, reduced complication risk
– Disadv.— limited tissue, bleeding (deep veins, IVH), metastatic
seeding (e.g.,
pineoblastoma)

57.  OPEN RESECTION:
larger tissue sample (esp. in heterogenous tumors),
reduced tumor burden (complete excision if benign)
 NEUROENDOSCOPIC BIOPSY:
– flexible endoscopes to simultaneously perform a third
ventriculostomy and biopsy through the same bur hole
– bleeding risks (similar to stereotactic biopsy)
– sampling bias

58. SURGICAL TECHNIQUES- STEREOTACTIC
SURGERY

59. BIOPSY—ENDOSCOPIC
 Tumor is biopsied along its ventricular surface,
where there is no tissue turgor to tamponade the
bleeding
 Flexible endoscopes
 Rigid scopes through a suitable entry point in forehead
 More typically used for– aspirate pineal cysts

60. OPERATIVE PROCEDURES
 Supratentorial approaches include
 Transcallosal interhemispheric
 Occipital transtentorial,
 Transcortical transventricular- rarely used.
 The infratentorial approach
is through a natural corridor created between the
tentorium and the cerebellum.

61. Patient Positioning - sitting
position
 This is usually preferred for the
infratentorial supracerebellar approach.
 Gravity works in the surgeon’s favor by
reducing pooling of blood in the
operative field and by facilitating
dissection of the tumor from the deep
venous system.
 The risks for air embolism,
pneumocephalus, or subdural hematoma
.
 Doppler monitoring helps detect small
amounts of air entering the venous
system during the operative procedure.
 A central venous catheter can be used to
remove entrapped air if necessary.

62.  The head is flexed so that
the tentorium is approximately
parallel to the floor.
 The patient’s legs should be
elevated to assist venous
return.
 A three-point vise type of head
holder keeps the head
immobile.
 At least two fingerbreadths of
space is needed between the
patient’s chin and sternum to
avoid compromising the
airway and venous return.

63. Lateral Position
 The lateral decubitus position with the dependent,
nondominant right hemisphere down is generally used.
 The head is raised approximately 30 degrees above the
horizontal in the midsagittal plane, especially for the
transcallosal approach.
 For the occipital transtentorial approach, the head should
be positioned with the patient’s nose rotated 30 degrees
toward the floor.

64.  A more desirable variation of
LATERAL POSITION is the
threequarter prone position.
 The legs are flexed with
a pillow between them, and the
patient is strapped down so that
the table can be rotated during
the procedure to improve
exposure when appropriate.
 The three-quarter prone
position is essentially an
extension of the lateral
position, except that the
head is at an oblique 45-degree
angle with the nondominant
hemisphere dependent.

65. THREE-QUARTER PRONE
POSITION.
 This is suitable for more posterior approaches, such as the
occipital transtentorial .
 The nondominant hemisphere is easily retracted with the help of
gravity.
 Surgeon fatigue is reduced because the surgeon’s hands are on a
horizontal plane and are not extended to the degree they are
with patients in the sitting position.
 Placing an axillary roll under the patient’s right axilla
with the right arm supported in a sling-like fashion beneath the
patient.
 A supporting roll is placed under the left thorax, and a
three-point head-pin vise holder is used to support the head in a
slightly extended and rotated position to the left at a 45-degree
oblique angle.

66. Prone Position
 The prone position is simple and safe for supratentorial
approaches .
 It is generally comfortable for the surgeon.
 This position is useful when two surgeons work together through an
operative microscope that has a bridge to allow simultaneous
binocular vision.
 The steep angle of the tentorium, however, makes the prone position
impractical for the infratentorial approach.
 This position is often useful in the pediatric population.
 To facilitate its use, the position of the head can be rotated
15 degrees away from the craniotomy side in a variation known
as the Concorde position.

67. PRONE POSITION

68. Concorde position.

69. (1) Infratentorial Supracerebellar
Approach (Stein`S)
 sitting position.
 If necessary, a ventricular drain can be
placed in the trigone of the lateral ventricle
through a burr hole in the
midpupillary line at the
lambdoid suture.
 A suboccipital exposure is begun through a linear midline incision
extending from just above the torcular and external occipital
protuberance down to the level of the C4 spinous process.
 The craniotomy is centered just below the torcular.

70. • A suboccipital exposure is begun through a linear
midline incision extending from 2cm above the
inionl of the C4 spinous process.
The craniotomy allows for visualization of the
torcular and lateral sinuses at its superior extent ,
Laterally taken just proximal to the mastoid groove
and
the inferior aspect is 1 to 1.5 cm above the
posterior rim of the foramen magnum.
5 × 3.5 cm in size.
four dural leaves. The superior leaf when
retracted allows for visualization of the superior
surface of the cerebel- lum and the reflection of
the torcular and lateral sinuses superiorly. The
lateral leaves maximize the horizontal expo- sure
while the inferior leaf supports the cerebellum.
a self-retaining retractor has been placed at the
inferior aspect of the opening. The Budde retractor
system has been affixed to the Mayfield head
holder and superior and inferior malleable arms
attached. A continuous-drip needle irrigator can
also be attached to the retractor system. The dura
is tented to the Budde retractor using 4-0 Nurolon
suture and bone wax. Following the dural opening
one can now visualize the superior surface of the
cerebellum and tentorium.
Bipolar electrocoagulation of the bridging veins is
then followed by sharp separation. In the sitting
position this will allow for an increase in the vertical
extent of the corridor by 1 to 1.5 cm given the pull
of gravity on the cerebellum.

71. Bridging veins between cerebellum and overlying tentorial surface are located medially
as well as laterally.

72. Infratentorial supracerebellar view into the pineal region.
Theprecentralcerebellarvein(Pre.Cent.Cereb.V.)hasbeendivided. The internal occipital (Int. Occ. V.), basal vein (Bas. V.) and
pineal veins (Pineal V.) drain into the great vein of Galen (V. Galen). The vermis is retracted downward to expose the superior
(Sup. Cill.) and inferior colliculi (Inf. Coll.). The posterior cerebral (P. C. A.) and medial posterior choroidal arteries (Med. Post.
Ch. A.) are lateral to the pineal gland (Pineal). Tentorium (Tent.), occipital lobe (Occ.
Lobe). Tentorium (Tent.)

74. Infratentorial Supracerebellar
Approach (Stein`S)
 The bony opening must be sufficient to provide access for the surgical
instruments and adequate light from the operating microscope.
 A craniotomy is preferred over a craniectomy .
 Slots are drilled over the sagittal sinus, above the torcular, and over both lateral
sinuses.
 A final slot is drilled approximately 1 or 2 cm above the foramen magnum in the
midline.
 A craniotome is used to connect the slots, which allows the bone flap to be
elevated.
 Sufficient bone should be removed above the transverse sinus to ensure that
the view along the tentorium is not obscured.

75.  The dura is opened in a gentle semilunar curve that extends
from the lateral aspects of the exposure.
 The dural flap is reflected upward.
 Excess retraction obstructs the sinuses and should
be avoided.
 If the posterior fossa is tight, fluid can be removed from a
ventricular drain or by opening the cisterna
magna.

76.  Arachnoidal adhesions and midline bridging veins
between the dorsal surface of the cerebellum and the
tentorium are cauterized and carefully divided.
 Cauterizing the bridging veins and dividing them
midway can minimize the nuisance of bleeding from
the sinus.
 When these attachments are divided, the cerebellum
drops away from the tentorium to provide an excellent
corridor with minimal brain retraction.

77.  The operating microscope is brought in at this time.
 The arachnoid overlying the quadrigeminal plate is sharply
opened.
 This is generally an avascular plane, and minimal cautery is
necessary.
 The precentral cerebellar vein is identified as it courses
from the anterior vermis to the vein of Galen and should be
carefully dissected, cauterized, and divided.

78.  The trajectory of the
microscope is adjusted
downward along the
central axis of the tumor
away from the initial plane
parallel to the tentorium,
where it would otherwise
lead to direct encounter
with the vein of Galen

79.  With the posterior surface of the tumor exposed, the central
portion is cauterized and opened with a long-handled knife or
bayonet scissors .
 Specimens can be taken from within the capsule and sent for
frozen diagnosis.
 The tumor is then internally debulked with a variety of
instruments such as suction, cautery, tumor forceps, and a
Cavitron ultrasonic aspirator if necessary.
 As the tumor is decompressed, the capsule can be separated
from the surrounding thalamus.
 Most of the vessels along the wall of the capsule are choroidal
vessels and need not be preserved.

81.  The dissection continues until the third ventricle is
encountered.
 The tumor is then carefully dissected inferiorly off the
brainstem.
 This is often the most difficult portion of the tumor
dissection and can be facilitated by retracting the tumor
superiorly and dissecting it bluntly off the brainstem under
direct vision.
 Finally, the tumor is removed superiorly after separating
the attachments along the velum interpositum and the
deep venous system.

82.  Once tumor removal is completed, the surgeon should have a
comprehensive view into the third ventricle .
 Flexible mirrors can be useful for examining the inferior portion
of the tumor bed to verify the extent of resection and to avoid
leaving any blood clots. Careful attention must be given to hemostasis.
 Generally, direct but careful cautery is preferable.
 It is advisable to avoid extensive use of hemostatic agents, which
can float into the ventricle and obstruct a shunt or the aqueduct.
 If absolutely necessary, long strips of Surgicel draped over
the surface of the cerebellum and covering the tumor bed
can provide hemostasis with small risk of floating into the
ventricle.

84.  Once hemostasis is obtained and the retractors are
removed, the dura is closed in as watertight a manner
as possible.
 The bone flap is plated into place to reduce
postoperative pain and inflammation.
 The patient should be extubated with a reasonable
degree of head elevation to avoid shifting the
decompressed brain within the cranial vault.

85. (2)Transcallosal Interhemispheric
Approach
 First described by Dandy
 This approach between the falx and hemisphere of the
brain involves a corridor along the parietooccipital
junction.
 prone or sitting position is generally preferred.

86.  Positioning of the bone flap depends
on where the tumor is
centered in the third ventricle.
 A wide craniotomy roughly 8 cm in
length.
 The craniotomy is generally centered
over the vertex to avoid manipulation
of the occipital lobe.
 A U-shaped scalp flap extending
across the midline and reflected
laterally provides adequate exposure.
 A bur hole is made over the sagittal
sinus, both anteriorly and posteriorly,
and a craniotome is used to turn a
generous craniotomy.
 The craniotomy should extend 1 to 2
cm to the left of the sagittal sinus.
Bleeding from the sagittal sinus can
be controlled with hemostatic agents.

87.  The dura is opened in U-shaped fashion and
reflected medially toward the sagittal sinus.
 Approach is chosen that will minimize the
number of veins sacrificed.
 It is unlikely that sufficient exposure can be
achieved without sacrificing at least one bridging
vein, although sacrifice
of more than one should be avoided if possible.
 Because these tumors are deeply seated, even a
small opening provides a wide angle of deep
exposure.
 This is generally a nonvascular corridor with few
adhesions between the falx and the cingulate
gyrus.

88.  The corpus callosum is easily identified with the by its
striking white appearance.
 The pericallosal arteries are identified as a paired structure
running over the corpus callosum.
 These arteries are retracted either to one side or with
separate retractors to each side.
 The opening into the corpus callosum, centered over the
maximal bulge of the tumor, is generally about 2 cm, which
is not likely to lead to disconnection syndrome or cognitive
impairment

89.  If necessary, the
tentorium and falx can
be divided to
provide additional
exposure .

90. •The corpus callosum is
generally thin and can be
opened with gentle
suction and cautery.
•The lateral extent of the
opening is determined by
the amount that is
sufficient to expose the
tumor and avoid damage
to the pericallosal
arteries.

92. Operative photograph demonstrating tumor exposure and
the internal cerebral vein overlying the tumor.

93.  Once through the corpus callosum, the dorsal surface of
the tumor can be seen, and the veins of the deep venous
system must be identified early to prevent damage to them.
 Once the tumor is exposed, it is debulked and then
dissected.
 Leaving a ventricular drain in place for 1 or 2 days is
optional.

94. (3)Occipital Transtentorial
Approach(Poppen`S)
 A three quarter prone position
is generally preferred.
 This approach to the pineal region uses an oblique
trajectory for lesions that are essentially midline and may
therefore be disorienting to surgeons who are not familiar
with it.
 However, by dividing the tentorium, excellent exposure of
the quadrigeminal plate is achieved, thus making it
particularly useful for tumors that extend inferiorly.

95. A, supine position; B, park bench position;
C, three-quarter prone position; D, head is
rotated 45° and flexed 30°; E, head is
tilted 15°; F, final position in Mayfield
headholder; G, position of surgeon and
assistant in relation to the patient.

96. A) indicates the location of
the skin incision and bone
flap on the skull.
B) The incision is made from
the inion along the midline
and then curved in a
horseshoe fashion back
behind the right ear.
C) The bone flap should be 8
cm along the superior
sagittal sinus and 7 cm along
the transverse sinus.

97. A) The dura is opened into two
triangular flaps based on the superior
sagittal sinus and the transverse sinus
B) A relaxing incision is made in the
dura at the anterolateral comer of
the craniotomy
C) A malleable brain retractor is then
fixed to the Leyla arm and the
occipital lobe is retracted gently

98. A) the splenium and the thick arachnoid
over the vein of Galen can be visualized.
B) After bipolar coagulation of the
tentorium just lateral to the straight sinus,
an incision is made along the coagulated
tentorium.
C) The thick arachnoid membranes over the
vein of Galen are dissected sharply, and the
precentral cerebellar vein and the vein of
Galen are identified

101.  A U-shaped right occipital scalp flap is reflected
inferiorly, with the medial vertical limb beginning just
to the left of midline at about the level of the torcular.
 A bur hole is placed in the midline over the sagittal
sinus just above the torcular, along with another bur
hole 6 to 10 cm above this.
 A craniotome is then used to turn a generous
craniotomy extending 1 to 2 cm left of midline.

102.  With the three-quarter prone position, gravity helps
with retraction of the nondominant occipital lobe,
which is also facilitated by the lack of bridging veins
near the occipital pole.
 Mannitol and ventricular drainage are useful for
relaxing the brain and minimizing the risk for
hemianopia from excessive occipital lobe retraction.

103.  Under the operating microscope, the straight sinus is
identified so that the tentorium can be divided
adjacent to it.
 A retractor can be placed over the falx for exposure.
 The inferior sagittal sinus and falx can be divided to
facilitate further falcine retraction.
 At this point, the arachnoid overlying the tumor and
the quadrigeminal cisterns can be seen.
 Tumor removal proceeds as described earlier while
taking care to avoid injury to the deep venous system.
Closure and hemostasis proceed as described
previously.

104. Operative photo demonstrating
tumor after the tentorium is
divided.
D, Operative
photo after tumor
removal.

105. (4)Transcortical Transventricular
Approach (Van Wagenen`s)
 The transcortical transventricular approach was developed
by Van Wagenen, who used a trajectory through the right
lateral ventricle via a transcortical incision.
 This approach is rarely used because the exposure is
limited and the need for a cortical incision is undesirable.
 Obviously, an entry point should be chosen in noneloquent
cortex.
 Stereotactic guidance is often useful with this approach
and may be desirable for a tumor that extends into the
lateral ventricle.

106. POSTOPERATIVE CARE
 High-dose steroids— first few days, then tapered;
 seizure prophylaxis
 Common initial problems:
– lethargy and mild cognitive impairment— particularly patients with extensive subdural air as a result
of the sitting position
 careful and frequent neurological examinations
 CT to rule out hydrocephalus, hemorrhage, or residual air
 – shunt malfunction—by air, blood, or operative debris
 mobilize and ambulate as early as possible
– ataxic patients— physical therapy and rehabilitation consultation
 Ventricular drain— removed or converted to a shunt within the first 72 hours to minimize infection
risk
 CEMRI within 72 hours— extent of resection, future management decisions

107. COMPLICATIONS
 More in previously irradiated patients, patients with
invasive tumors, and those who were progressively
symptomatic preoperatively.
 Common, self-limiting (few days to few months):
– EOM—limited upgaze and convergence
– mild upgaze palsy may persist
– pupillary impairment with difficulty focusing
– ataxia

108.  Major (unusual):
– hemorrhage from tumor bed— conservative/evacuation
– venous infarcts, involving midbrain
– cognitive impairment/akinetic mutism (brainstem
manipulation)
 Supratentorial approach-related:
– hemiparesis (brain retraction/ sacrifice of bridging veins)
– C/L sensory or stereognostic deficits (parietal lobe retraction)
– visual field defects (occipital lobe retraction)
– disconnection syndromes (corpus callosum incisions)
 Infratentorial approach-related:
– subdural hematoma, hygroma, and ventricular collapse
– air embolism

109. SURGICAL OUTCOME

110. RADIATION

111. CHEMOTHERAPY
 Non-germinomatous malignant GCTs, recurrent/disseminated pineal
cell tumors
 Regimens:
– most accepted — cisplatin/carboplatin + etoposide
– experimental:
 Einhorn regimen (testicular ca.) — cisplatin + vinblastine + bleomycin
 Chemoradiation:
– no clear-cut benefits/protocols; some reports suggest improved
outcomes
– germinomas with syncytiotrophoblastic giant cells
– ? reduce irradiation dose
– delayed surgery after chemoradiation — residual tumors whose germ
cell markers have normalized.

112. References
 Principles of neurosurgery, by setti rengachary &
richard G. Ellenbogen
 Neurosurgery, second edition, by SETTI S.
Rengachary, m.D, robert h. Wilkins, m.D.
 Brain tumors, an encyclopedic approach, third
edition, part 5, 34, 646-671
 Youmans & winn neurosurgical surgery, seventh
edition, 141

113. References
 Neurosurgical operative atlas, aans publications
committee, setti s. Rengachary, m.D, robert h. Wilkins,
m.D., SUPRACEREBELLAR INFRATENTORIAL
APPROACHES TO THE PINEAL REGION by MICHAEL L.
Levy, m.D. Michael l. J. Apuzzo, m.D.
 Neurosurgical operative atlas, aans publications
committee, setti s. Rengachary, m.D, robert h. Wilkins,
m.D OCCIPITAL TRANSTENTORIAL APPROACH TO
PINEAL REGION NEOPLASMS by JAMES I. Ausman,
m.D., Ph.D. Balaji sadasivan, m.D.
 From the archives of the afip lesions of the pineal
region: radiologic- pathologic correlation alice boyd
smith, lt col, usaf mc • elisabeth j. Rushing, COL, MC, USA •
james G. Smirniotopoulos, MD