Anatomy and related vascular structures of pineal region.pathological classification and incidence. Clinical Presentations and different diagnostics modalities. Different surgical approaches for pineal region

2. Medhat Mustafa, MD,
Department of Neurosurgery
Suez Canal University, Ismailia, Egypt

3. PINEAL REGION TUMORS
DIAGNOSIS & SURGICAL
APPROACHES

4. Objectives
Anatomy
Vascular relations
Pathological types
Diagnosis
Treatment

5. Normal anatomy
of pineal region

6. The pineal gland is a small (5-8 mm AP
diameter), pine-cone shaped, midline
brain structure.

7. It is located in the
quadrigeminal
cistern posteriorly
to the third
ventricle, inferiorly
to the splenium of
the corpus
callosum and the
internal cerebral
veins and
superiorly to the
tectal plate of
midbrain.

8. The presence of calcifications with a
diameter greater than 1 cm or before the
age of 10 is mainly pathologic.

9. The choroidal branches of the
posterior cerebral artery are
the feeding vessels of the gland.

10. ARTERIAL SUPPLY
PCA
• – P1
• Quadrigeminal a.– superior colliculi
– P2
• M P.ch – Pineal body, corpora quadrigemina, tela choroidea ventriculi
, thalamus
• L Pch – Choroid plexus of lat. Ventricle, LGB, thalamus

13. ARTERIAL SUPPLY
– P3/P4
• Medial occipital artery
– Calcarine artery – calcarine sulcus –
Parieto-occipital artery – parieto-occipital
sulcus
• Posterior pericallosal artery
– SCA
• Inferior colliculi

14. • Great cerebral vein of Galen
– Pineal veins(sup & inf)
-- pineal body, trigonum habenulae
– Quadrigeminal veins(sup&inf)
—corpora quadrigemina
– Superior vermian vein
– superior vermis
– Precentral cerebellar vein
– cerebellum, superior cerebellar peduncle
– Posterior pericallosal vein
– Internal occipital vein

17. •VEINS OF PINEAL REGION
• Internal cerebral veins
– Septal veins(ant&post) –septum pellluvidum – Anterior caudate vein
– caudate nucleus – Thalamostriate(terminal) vein – Choroidal vein –
choroid plexus lat. Ventricle – Medial atrial (trigonal)vein – Trigone –
Direct lateral veins

18. VEINS OF PINEAL REGION
• Basal vein of Rosenthal
– Vena cerebri media profunda
– Venae centrales (striate) inferiores
– Vena cerebri anterior
– Vena apicis cornua temporalis (hippocampal vein)
– Vena atrii lateralis (lateral atrial vein )
– Vena cornus temporalis (atriotemporal vein )

19. Pathology
• Pineal gland tumors

20. Pathology
There is a wide range of pineal
region masses
due to the multiple different cell
types found there.

22. Pathology
• Tumors arising from the pineal gland
are mainly classified into germ cells
and pineal parenchymal tumors.

24. Pathology
• Germ cell tumors
• are the most common,
representing more than 50% of
pineal tumors.

25. Pathology
Germ cell tumors
They are divided into non-germinomatous
and germinomatous.
Based on the literature, germ cell tumors affecting the
pineal region most frequently occur in males, especially non-
germinomatous tumors with an incidence of 90%.

26. Germ cell tumor
Germinoma Nongerminoma
embryonic extraembryonic
Mature Immature choriocarcinomas yolk sac carcinomas
Teratoma embryonal carcinoma

27. Germ cell tumors
Germinomas
constitute the majority, accounting for 60-80% of all
germ cell intracranial neoplasms, 3-5% of intracranial
tumors in children and 0.4-1% of intracranial tumors
in adults.

28. Germ cell tumors
Non-germinomatous germ cell tumors
(teratomas, embryonal carcinomas,
choriocarcinomas and yolk sac carcinomas) are rare.
Teratomas are the second more common
germ cell tumor in the pineal gland.

29. Pathology
Tumors arising from pineal parenchyma
account for 14-27% of pineal gland tumors
Pineocytoma,
pineoblastoma,
pineal parenchymal tumor of intermediate differentiation (PPTID)
papillary tumor of the pineal region (PTPR) are included.

30. Pineocytomas are reported to account for up to 30% of pineal tumors.
Pineoblastoma is a common malignant tumor detected to the
pineal region, with an incidence up to 50%.
PPTID are less often, but account for at least 20% of this category of
tumor.
Pathology
Tumors arising from pineal parenchyma

31. Pathology
The remaining 25% of pineal region lesions include pineal
cysts masses expanding from adjacent anatomical
structures, such as gliomas arising from the adjacent brain
parenchyma and meningiomas arising from the tentorium.
Lipomas, pineal cysts, metastases and arachnoid cysts are
also included.

32. Germinomas
are mainly seen in children and young adults, with a
peak at the age of 10-12. Approximately, 90% of the
patients are less than 20 years old at the time of
diagnosis.
Pathology

33. Germinoma
is histologically similar to dysgerminoma of the ovary
and seminoma of the testis.
It is identified in the pineal region (50-65%), the suprasellar
region (30%) and the basal ganglia-thalamus (5-10%).
Pathology

34. Pathology
Germinomas
are mainly aggressive tumors that often infiltrate the
adjacent anatomical structures and spread
through the cerebrospinal fluid (CSF) into
the spinal canal.

36. Teratomas
are distinguished in mature, immature and those
with malignant transformation, with Alpha
fetoprotein (AFP) and Human chorionic gonadotropin
(HCG) elevated in immature type.

37. Pathology
Teratomas
more often occur in children under 10 years of age.
The most common location is the
pineal region, but they may also occur in the
third ventricle and posterior fossa.

38. Pathology
The rest of the non-germinomatous germ cell
tumors are highly malignant.
AFP and HCG in CSF are elevated in yolk sac
carcinoma and choriocarcinoma respectively.

39. Pathology
Pineocytomas
(WHO 2016, grade I) are benign tumors, most
commonly presented in adults with a mean age of
38 years old.
It is extremely rare for them to metastasize
and spread into the spinal canal.

40. Pathology
Pineoblastomas
(WHO 2016, grade IV)
are highly malignant tumors mainly affecting
children and young adults under 20 years old.
The tumor infiltrates adjacent
anatomical structures and often spreads into
the spinal canal.

42. Pathology
PPTID
(WHO 2016, grade II or III) has
histological features between those of
pineocytoma and pineoblastoma without an
age restriction, although there is a peak age
in young adults.
It rarely causes drop metastases.

43. Pathology
PTPR
(WHO 2016, grade II or III) is a
neuro-epithelial neoplasm arising from
ependymocytes of the subcommissular
organ. It affects a wide range of ages from 5
to 65 years old. Drop metastases arise in 7%
of the cases.

44. Clinical presentation

45. Clinical presentation
The symptoms are related to tumor
local invasion and/or compression of adjacent
structures, depending on the size and
aggressiveness of the mass.

46. Clinical presentation
Compression of the midbrain anteriorly
with obstruction of the aqueduct of Sylvius
leads to obstructive hydrocephalus and
symptoms of increased intracranial pressure.

47. Clinical presentation
Compression of the tectal plate causes
visual problems (Parinaud syndrome)
Infiltration of the thalamus may lead to loss
of sensation and weakness on one side of
the body.

48. Clinical presentation
When the tumor expands into the
suprasellar region, symptoms related to the
hypothalamus may occur.
Precocious puberty is a result of elevated HCG.

49. Imaging

51. CT and MRI are critical for the evaluation
of the location, size and shape of the
pineal tumor. The imaging findings are not
specific.

52. The differential diagnosis is difficult
and often a biopsy is required to determine
the histological type.

53. However, there are crucial
signs that could narrow the
differential diagnosis.

54. In the presence of calcifications,
the pattern of involvement is helpful
Germinomas tend to engulf the
calcifications,
in contrast to pineal parenchymal
tumors, where calcifications are
distributed.

55. Additionally, some tumors, like
pineoblastomas,
infiltrate adjacent structures, the
third ventricle and the basal
cisterns, whereas
others like germinoma exhibit
edema.

56. A CT scan of the brain constitutes the
first imaging method and can be beneficial
for the assessment of the pineal region and
the presence of hydrocephalus,
calcifications and hemorrhage, although it
should be avoided in children due to
radiation.

57. MRI of the brain is considered the gold
standard method for the evaluation of
the CNS. This method is superior to CT
due to
the absence of radiation and its high
sensitivity,
the ability to illustrate anatomical
details of the brain and the excellent
separation of gray and white matter.

58. The imaging characteristics of pineal
germinoma
are not specific and include a
well-circumscribed, ovoid or lobulated,
relatively homogenous mass, that overwhelms
the pineal gland.

59. The signal on T1 and T2
WI is variable, most commonly slightly
hyperintense on both sequences.
They may demonstrate cystic or hemorrhagic
components and a tendency to invade the
adjacent tissues, surrounded by edema.

60. Markedly enhancement may be seen on MR, due to
their cellularity, either homogenous or inhomogeneous
with regard to their content

61. The differential diagnosis
between germinoma and pineal parenchymal
tumors is not accurate.
A helpful sign
could be the engulfment of the normal physiologic
calcification, while pineal parenchymal
tumors appear exploded.

62. If the imaging findings are present in a young male, the
diagnosis is in favor of germinoma.

63. Additionally, a hypointensity on T2WI may
also be helpful in the differential diagnosis
of a germinoma from a pineal parenchymal
tumor.

64. Teratoma is composed of all three germ
cell lines presenting a heterogeneous
appearance. The majority of non-germinomatous
germ cell tumors contain fat, calcifications
most often clump like, hemorrhage,
teeth, hair, cystic and solid components.

65. Hydrocephalus
occurs frequently.
Detection of a midline
heterogeneous mass in a child should suggest
the diagnosis of a teratoma.

66. Pineoblastoma,
a highly aggressive tumor may contain hemorrhagic, necrotic
or cystic foci.
MRI can identify the tumor and
the intrusion of the adjacent tissue but also
the presence of leptomeningeal and
subependymal metastases.
These tumors are
ill-defined because of their tendency to
infiltrate the surrounding structures.

67. On T2 WI, the majority is isointense, unless a
cystic component produces a high signal.
These tumors exhibit restriction on DWI and
intense, inhomogeneous enhancement after
Gd administration.

68. Central necrotic elements
must be differentiated from cystic by
the administration of Gd, whereas the differentiation
from a pineal cyst may be difficult.

69. Pineocytomas
are well defined
lesions with solid, enhanced components.
Cystic or hemorrhagic areas can be demonstrated,
thus the signal on T1 and T2 WI is
variable. The well defined contours are
helpful to the differential diagnosis in order
to distinguish them from pineoblastomas

70. A calcified pineal mass in a
female is more likely to represent a pineocytoma.

71. Regarding PTPR,
although the
presence of high signal on T1WI is a relatively
specific finding, variable signal intensity
on T1WI and hyperintensity on T2WI
are presented. According to Chang et al the
presence of high signal on T1WI may be
related to the concentration of protein and
glycoprotein content in the cystic regions
and this may be a common imaging finding
for papillary tumors.

72. Drop metastasis
is a term for intradural
extramedullary metastatic lesions of the
spine that result from subarachnoid spread
of a primary brain tumor.

73. They arise from
pineal tumors, ependymomas, medulloblastomas,
primitive neuroectodermal tumors
(PNET), glioblastomas multiform, anaplastic
astrocytomas and oligodendrogliomas.

74. Drop metastases
occur in 5% to 30% of children,
either early, at the time of diagnosis of a
brain tumor, or during the follow-up.
Medulloblastoma is the most common
source, accounting for half of the patients
with drop metastases.It is mainly diagnosed
in children under 10 years of age,
with a second smaller peak between 15 and
35 years old. Glioblastoma multiform is the
second most common tumor with an incidence
of 1% of cases and in 15% of all patients with drop metastases.

75. The two most common pineal tumors
causing drop metastases are germinomas
and pineoblastomas.
Leptomeningeal seeding has been
reported in 6% to 14% of patients with germinomas
and as high as 45% in all patients
with pineoblastomas.

76. Pineal metastasis is uncommon, affecting
5% of patients with pineal tumors who
underwent surgery. Lung cancer is the most
common cause, however breast, kidney and
gastrointestinal tract are also related.
Leptomeningeal spreading is common and
is present in 67% of patients.

77. Therapy

78. The therapeutic plan of pineal tumors
depends on the histological type, the size
and the presence of drop metastases.

79. Surgery in the pineal region is anatomically
difficult and is not usually possible to
completely remove the tumor.

80. Treatment
• RADIOTHERAPY
• CHEMOTHERAPY
• RADIOSURGERY
• BIOPSY :
OPEN BIOPSY
STEREOTACTIC BIOPSY
.craniotomy

81. ADJUVANT THERAPY
• RADIOTHERAPY
– For malignant germ cell/pineal cell tumors: 4000cGy :
Ventricular system 1500cGy : Tumor bed Ø180 cGy daily
fractions Ø 3500 cGy to spine if spinal seeding radiographically
documented. ØRT maybe withheld: for histologically benign
pineocytoma /ependymoma completely resected.

82. ADJUVANT THERAPY
• Germinoma with raised b- hCG has less favorable prognosis.
• Side effects of
– Cognitive deficits. – Hypothalamic/Endocrine dysfunction. –
Cerebral necrosis. – De novo tumor formation.

83. ADJUVANT THERAPY
• CHEMOTHERAPY
– Indications
• Non germinomatous malignant germ cell tumors
• Germinoma with syncytiotrophoblastic giant cells
• Recurrent /disseminated pineal cell tumors
– Cisplatin/carboplatin + Etoposide
– Others: vincrisNne/lomusNne/cyclophosphamide

84. RADIOSURGERY
• For tumors less than 3 cm
• For tumors that recur locally.

85. SURGICAL ANATOMY
• Most tumors arise from or attached to the undersurface of
velum interpositum.
• Tumors rarely extend above velum
. • 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
For. Monro.

86. SURGICAL ANATOMY
• Mostly, ICV, Galen , Rosenthal & precentral cerebellar veins
surround or cap the periphery of these tumors.
• Rarely, ICV are ventral to tumor.
• Most tumors are not highly vascular except
– Pineoblastomas
– Hemangioblastomas
– Hemangiopericytomas (Angioblastic meningioma)

87. •MANAGEMENT OF HYDROCEPHALUS
• If complete tumor removal is anticipated: EVD at
surgery: removal on POD:2/3
• Conversion to VP shunt
• ETV preferred :
– Gradual reduction of ICP
– Eliminates potential complications
• Infection
• Overshunting
• Peritoneal seeding by malignant cells

88. OPERATIVE
BIOPSY
• For adjuvant therapy
• Metastatic workup
• Prognosis & long term follow up.

89. OPERATIVE
• OPEN BIOPSY
– More extensive tissue sampling in view of heterogeneity & mixed cell
population
– Debulking: favorable response to adjuvant therapy
– Risk of postop. bleeding in incompletely resected tumor bed.

90. OPERATIVE
BIOPSY
• STEREOTACTIC BIOPSY
– Suited for patients with multiple lesions, clinical conditions that
contraindicate open surgery/ general anesthesia.
– Multiple specimens to be obtained.
– Side cutting cannula preferred over cup forceps
– Hemorrhage: Continuous suction & irrigation x 15 min.

91. OPERATIVE
STEREOTACTIC APPROACHES
• INDICATIONS
– For biopsy to achieve diagnosis
– Aspiration of cystic masses
– Radiosurgery for treatment : meningioma, pineocytoma, AVM
– As adjuvant management with chemotherapy for germ cell
neoplasms & pinealoblastomas.

92. OPERATIVE
STEREOTACTIC APPROACHES
• ADVANTAGES
– Resection may not be necessary depending on the histopathology
– Biopsy may guide effective non-surgical therapies
– Radiosurgery for small volume pathologies •
DISADVANTAGES
– Small biopsy volume : Difficulty in diagnosis
– Experienced neuropathology team required
– Risk of radiation related damage & deficits

93. OPERATIVE
STEREOTACTIC BIOPSY
• ANTEROLATEROSUPERIOR APPROACH:
– Low precoronal entry point just behind the hairline & just above the
superior temporal line
. – Needle trajectory: Through the frontal lobe , underneath the lateral
ventricle & lateral & inferior to ICV.
• POSEROLATEROSUPERIOR APPROACH:
– Entry point near PO junction, for tumors extending laterally or
superiorly.

94. OPERATIVE
ENDOSCOPY
• BIOPSY : In conjunction with ETV
• FLEXIBLE ENDOSCOPE : Limited trajectory to tumor through foramen
magnum
• RIGID ENDOSCOPE : Low frontal burr hole
• LIMITATIONS
• Limited tissue sampling
• Difficulty in hemostasis

96. OPERATIVE
INFRATENTORIAL SUPRACEREBELLAR
• INDICATIONS
– Tumor with major bulk in midline
– Tumor ventral to velum interpositum & deep venous system
• ADVANTAGES
– Minimal risk to deep veins
– No normal neural tissue violated enroute
– Exposure comparable with that of other routes

97. OPERATIVE
INFRATENTORIAL SUPRACEREBELLAR
• COMPLICATIONS
– Risks of sitting position
– Limited upgaze & convergence
– Ataxia
– Cognitive impairment
– Akinetic mutism
• More frequent in patients having preop deficits, prev. radiation or
invasive tumors

98. SURGICAL TECHNIQUE
• Postion: Sitting , ¾ prone, concorde
• Head flexed: tentorium parallel to floor
• Midline incision : inion- C3
• Burr holes: – At sagipal sinus above torcula
– At lateral aspect of transverse sinus
– Suboccipital Midline above for. magnum

99. SURGICAL TECHNIQUE
• Durotomy:gentle curving incision
• Microscope with variable objective/275mm
• Bridging & precentral cerebellar veins cauterized & divided.
• Until arachnoid is opened & cerebellum freed from brainstem, the
trajectory is to aimed at Vein of Galen to avoid injury to ICV/Rosenthal
V.

100. SURGICAL TECHNIQUE
• Internal debulking/capsule dissection
• Most difficult & dangerous part : inferior portion of tumor adherent
to dorsal midbrain.
• Copious irrigation to remove all clots that can block aqueduct.

101. LATERAL PARAMEDIAN INFRATENTORIAL
• INDICATIONS
• Biopsy
• Small quadrigeminal area tumor
• ADVANTAGE
• Minimal damage to neural Nssues
• Useful in steep tentorium
• Reduced risk of air embolism •
DISADVANTAGES
• Narrow space
• Difficult to reach tumor portion extending to inferoposterior part of 3rd ventricle

102. LATERAL PARAMEDIAN INFRATENTORIAL
• POSITION
– On the side: usually right side down
– Upper part of trunk raised 30`
– Head flexed with neck stretched & rotated 45` face down

103. LATERAL PARAMEDIAN INFRATENT
• 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.

104. SUPRATENTORIAL APPROACH
• INDICATIONS
– Tumors extending superiorly
– Tumors involving or destroying the posterior aspect of corpus
callosum
– Tumors deflecting the deep venous system dorsolaterally
– Tumors extending laterally to region of trigone
– Tumors displacing deep veins in ventral direction ( e.g..
Meningiomas)

105. OCCIPITAL TRANSTENTORIAL
• INDICATIONS
• Tumors straddling or lying above the tentorial notch
• Vascular lesions : varices of vein of Galen, AVM, P3/4 PCA aneurysms.
• ADVANTAGES • Excellent view both above & below the notch •
DISADVANTAGES • Damage to occ. Lobe: visual field defects. • Damage
to splenium • Difficult to access subtentorial C/L porNon of tumor

106. OCCIPITAL TRANSTENTORIAL
• Surgical technique
– Position: semiprone with nondominant side down
– Incision: U-shape
– Craniotomy : 6 burr holes : 2 on left, 2 on right of sag. Sinus ,1 just
rostral to trans. Sinus & 1 parietal.
– Durotomy: T- shape & reflected along sinuses
– Retractor on inferior surface of occipital lobe

107. OCCIPITAL TRANSTENTORIAL
• Falx retracted medially
• Ventricular drain placed in occipital horn
• Tentorium cut 1-1.5 cm from & parallel to straight sinus. •
Quadrigeminal cistern opened , CSF drained
• Veins visualized : Galen vein – right Rosenthal —ICV—precentral
cerebellar

108. OCCIPITAL TRANSTENTORIAL
• 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 apempted.
• Immaculate hemostasis, water-tight dura closure.

109. TRANS -VELUM INTERPOSITUM
• INDICATIONS
• Huge tumors in pineal region/posterior 3rd ventricle
• Tumors extending anterior to adhesio interthalamica
• ADVANTAGES
• Tumors extending into lateral ventricular can also be managed •
DISADVANTAGES
• Damage to anterior corpus callosum
• Damage to fornix

110. TRANS -VELUM INTERPOSITUM
• Surgical technique
– Position : Supine with head elevation 20` in pin
– Coronal/Quadrangular skin flap on nondominant side
– Quadrangular bone flap , extending to midline & anterior to coronal
suture
– Right frontal lobe retracted, corpus callosum exposed , split 3-4 cm to
enter pars centralis

111. TRANS -VELUM INTERPOSITUM
• Velum interpositum ( choroid plexus + tela choroidea + ICV ) cut just
lateral to tenia fornicis & medial to choroid plexus of lateral ventricle •
B/L fornices & IJV retracted medially to explore tumor b/w these
structures & right thalamus

112. • Indications
– Large tumors > 4.5 cm
–Tumor arising from tentorium or extending above & below
– Tumor well below plane of cerebellar retraction ( 2cm below sup.
Surface of cerebellum)
– Very vascular tumors
– Tumors encasing imp. Venous structures.

113. COMBINED SUPRA-INFRATENT. TRANSSINUS
• Cerebral angiogram is mandatory to look for venous anatomy, size &
communicaNon b/w transverse sinus & deep venous system.
• VP Shunt 2-4 weeks prior to planned surgery
• Somatosensory evoked potenNals from UL & LL B/L & BAER
monitoring during surgery
• Position : Semiprone with proposed trans. Sinus section placed
inferiorly.

114. COMBINED SUPRA-INFRATENT. TRANSSINUS
• U-shape incision
• Burr holes inferior to trans. Sinus (4) & just above for. Magnum (2)
– suboccipital craniotomy
• Trans. Sinus separated & occipital craniotomy performed on one side
followed by other.
• Suboccipital dura opened in transverse fashion inferior to trans. Sinus

115. COMBINED SUPRA-INFRATENT. TRANSSINUS
• Occipital dura is then opened parallel to sinuses
• 20 G buperfly needle inserted in trans. Sinus just lateral to torcula &
medial to temporary clip placed for test occlusion x 5 min.
• Nondominant trans. Sinus can be safely sectioned if : venous
pressure > 5 mm Hg, no brain swelling, no change in evoked potentials.
• Tentorium is then cut parallel to straight sinus.

116. COMBINED SUPRA-INFRATENT. TRANSSINUS
• Deep vein injury : repair with 7-0 prolene/8-0 nylon
• Trans. Sinus can be reconstructed with a short vein gray interposed
with 6-0 prolene.
• Not necessary to suture tentorium
• Dural gray to allow watertight closure & expansion of posterior fossa.
• If brain swelling + : suboccipital bone kept out.

117. COMBINED SUPRA-INFRATENT. TRANSSINUS
• Postoperative Care
– Look for respiratory abnea in tumors compressing brainstem
– CT on POD1 to l/f pneumocephalus/clots
– Nystagmus/ataxia/oscillopsia
– Ventricular drain x 3-4 days – 20 cm above head x 24 hrs– test
clamping x 24 hrs with ICP monitoring
—CT to l/f ventricle size.
– Vision abnormalities

118. COMPLICATIONS OF SURGERY
• Postop. Hemorrhage/apoplexy
• Pupillary abn., accomodation abn., ocular palsies, upward gaze
paresis, ataxia, impaired consciousness, shunt malfunction, ETV
blockage.
• Sitting position: air embolism, hypotension, cortical collapse,
subdural hygroma
• Parietal approaches: sensory/stereognostic deficits.
• Occipital : Visual field defects

119. Thank you