Pineal region imaging and pathology

1. Posterior Third ventricle and Pineal
region : Anatomy and Pathology
including Imaging

2. OVERVIEW
 Introduction
 Embryology,
 Anatomy of pineal region, Histology and function of pineal
gland
 Classification of Pineal region masses
 Pineal parenchymal tumours – pathology including genomics
and imaging
 Germ cell tumours- pathology including genomics and
imaging
 Other pineal region masses
 Pineal and pineal like cysts
 Cases of SCTIMST
 Quiz
 Questions

3. Introduction
 The pineal gland alias pineal body, conarium, epiphysis
 cerebri or the third eye, is a small endocrine gland in the vertebrate brain
(circumventricular organs)
 The shape of the gland resembles a pine cone, hence its name.
 Criticality of location – challenge to neurosurgeons, and accurate
preoperative assessment is essential.
 Diverse histology - pineal parenchymal cells, astrocytes, and
sympathetic neurons., in the gland. adjacent to the pineal gland -
ependymal cells (lining the third ventricle), choroid plexus cells,
arachnoid cells that form the velum interpositum, and astrocytes in the
brainstem, thalamus, and corpus callosum splenium.
 Broad spectrum of lesions including neoplastic and non neoplastic ,
congenital entities.
 Overall, pineal region tumors are rare, accounting for 1-3% of all
intracranial
 Neoplasms( 3-8% in children and <1% in adults)

4. Embryology
 (7th-8th week) Develops from neuroectoderm of posterior
portion of roof of diencephalon, remains attached to brain by
a short stalk.

6. Anatomy of Pineal region
 Pineal gland
 Posterior third ventricle and aqueduct
 Supraclinoid cisterns - quadrigeminal plate, ambient
cisterns, and the velum interpositium
 Brain - tectum and brainstem, thalami, corpus
callosum splenium
 Dura - tentorial apex
 Vessels - ICV & VOG , and PChA & PCA

7. Third ventricle and commissures
 Pineal gland abuts
the posterior third
ventricle
 Two CSF
outpouchings –
Suprapineal and
Pineal recesses
 Two commissures-
Posterior and
habenular.

8. Fornix
 C shaped
structure
 Crura
 Commissure
 Body
 Columns
 Forms medial
wall of lateral
ventricle
 Efferent output
of hippocampus

9. Velum interpositum
 The tela choroidea -The VI
stretches between the bodies of
the two fornices.
 The VI forms the roof of the third
ventricle ,closed anteriorly at the
foramen of Monro.
 If it is open posteriorly, it forms a
CSF filled space that
communicates directly with the
quadrigeminal cistern - a cavum
of the velum interpositum or
cistern of the velum
interpositum.

10. Quadrigeminal cistern
 Quadrigeminal cistern
- A Rhomboidal space
 Dorsal to tectum and pineal
gland
 Anteriorly to VI, laterally to
ambient cisterns.
 Inferiorly to superior vermian
cistern
 Superiorly falcotentorial
junction

11. Anatomy continued..
 Meninges
 Falcotentorial junction
 Veins and sinuses
 ICV, BVR -VOG - ISS -Straight Sinus.
 Arteries
 PCA - medial posterior choroidal arteries – pineal
gland
 Other parenchymal structures
 Splenium of CC, Tectal plate, Thalamus

18. Histology
 Lobules of pineocytes (95%) and astrocytes (5%) separated by a
fibrovascular stroma make up the normal gland.
 The pineocyte is a specialized neuron related to the retinal rods and
cones.
 Concentric calcifications, known as corpora arenacea
 Reported prevalence is 1% in children under age 6 years, 8% in
patients under age 10, and 40% in patients under 30. > 50% of
adults have calcified pineal glands.
 Germ cells : Not a constituent . Native stem cells of pluripotent or
neural type , the source of neoplastically transformed germ cell
element
 The pineal gland does not have a blood-brain barrier and therefore
enhances on contrast material–enhanced images.

19. Clusters and rosettes (arrow) of
normal pineocytes within a fibrous
stroma.
Pineocytes are a specialized type of
neuroepithelial cell, closely related to
neurons, that have photosensory and
neuroendocrine functions. Pineocytes
stain avidly with neuronal
immunohistochemical markers (e.g.,
synaptophysin and
neurofilament protein

20. Function of pineal gland
 Melatonin
 synchronization of seasonal reproductive rhythms and
entrainment of circadian cycles.
 Influenced by the dark/light cycle, the protein-coupled
metabotropic melatonin receptors MT1 and MT2 are the
primary mediators of its physiologic actions.
 Production of melatonin by the pineal gland is under the
influence of the suprachiasmaticnucleus(SCN) of the
hypothalamus which receives information from the retina about
the daily pattern of light and darkness

22. Clinical Presentation
 Compression of the tectal plate - obstruction of the sylvian
aqueduct and obstructive hydrocephalus increased ICT - as
seizures, headaches, nausea and vomiting.
 Direct compression of the midbrain - Cerebellar, corticospinal or
sensory disturbance .
 Interfere with normal pineal gland function and lead to
precocious puberty, less commonly hypogonadism and
diabetes insipidus.
 Pineal Apoplexy- Haemorrhage into a pineal tumor or cyst;
sudden decrease in consciousness associated with headache.

23. Parinaud's syndrome
 A cluster of abnormalities of eye movement and pupil dysfunction,
characterized by: MLF
 Paralysis of upwards gaze: Downward gaze is usually preserved. This
vertical palsy is supranuclear.
 Pseudo Argyll Robertson Pupil: Accommodative paresis ensues, and
pupils become mid-dilated and show light-near dissociation.
 Convergence-retraction nystagmus: Attempts at upward gaze often
produce this phenomenon. On fast up-gaze, the eyes pull in and the globes
retract.
 Eyelid retraction (collier’s sign)
 Conjugate down gaze in the primary position: "setting-sun sign".
Neurosurgeons see this sign most commonly in patients with
failed hydrocephalus shunts.

24. Classification: cell type
Pineal parenchymal tumors
 Pineocytoma
 PPTID
 Pineoblastoma
 PTPR
Germ Cell tumors
 Germinoma
 Non germinomatous germ cell tumor
Glial tumors
 Astrocytoma
 Oligodendroglioma
 Ependymoma

25. Others
 Meningioma
 Chemodectoma
 Craniopharyngioma
 Metastases
Non Neoplastic
 Cysts
 Dermoid cyst
 Arachnoid cyst
 Lipoma

26. Classification:Age
 Germinomas
 Teratomas
 Pineoblastomas
 Gliomas
 Children Adults
 Pineocytomas
 PPTID
 PTPR
 Meningiomas

27. Classification: Malignant potential
 Pineocytomas
 Pineal cysts
 Benign Malignant
 Germinomas
 Teratomas
 Pineoblastomas
 PPTID (varying grade)
 PTPR - uncertain

28. Tumors of Pineal Parenchymal Origin
 Pineal parenchymal tumors (PPTs) intrinsic primary
neuronal tumors that arise from pineocytes or their
precursors.
 PPTs account for less than 0.2% of all brain tumors but
cause approximately 15-30% of pineal gland tumors.
 These lesions include:
 Low-grade Pineocytoma,
 Intermediate-grade pineal parenchymal tumor of
intermediate differentiation (PPTID)
 Highly malignant Pineoblastoma
 Papillary tumor of Pineal region (PTPR)

29. Pineocytoma
 Slow-growing, WHO grade I
pineal parenchymal tumor of
young adults composed of small,
uniform mature cells resembling
pineocytes
 Pineocytomas constitute
approximately 14% to 30% of all
pineal parenchymal tumors and
present in all ages but are more
common in adults from the third to
sixth decades.
 No gender predilection

30. Pathologic and Histologic Features
 Sheets of mature-appearing cells
arranged in lobules, with rare or
absent mitotic figures, and no
pleomorphism, hyperchromatic
nuclei, or necrosis.
 Normal pineal gland architecture.
 Immunopositivity for neuronal
markers such as synaptophysin,
neuron-specific enolase, and
neurofilament protein (NFP) is
typical.
Shows small, uniform cells that resemble
normal pineocytes. Many of these are
arranged in rosettes (arrowheads)

31. Imaging Findings
 Location – Pineal region; rarely
posterior 3rd ventricle
 CT
 CT demonstrates the mass to be of
intermediate density, similar to the
adjacent brain.
 MRI
 T1: hypo to isointense to brain
parenchyma
 T2
 solid components are isointense
to brain parenchyma
 areas of cystic change are
common
 sometimes the majority of the
tumor is cystic
 T1 C+ (Gd): solid components
avidly enhance

33. Differential Diagnosis
 Pineoblastoma: Larger, More heterogeneous, Mass effect,
Parenchymal invasion, CSF spread & Younger patients
 Nonneoplastic pineal cyst: Cystic mass, typically < 1 cm,
may be up to 2 cm, variable calcification and cyst fluid, no or
minimal rim enhancement, compressed enhancing gland
often seen posteriorly
 Germinomas: "Engulfs" calcified pineal gland, intensely
enhancing pineal mass, often homogeneous, often CSF
spread at diagnosis, hyperdense on CT, typically young male
patients
 Astrocytoma, Other germ cell tumors, Meningiomas.

34. Pineal Parenchymal Tumor of
Intermediate Differentiation (PPTID)
 Intermediate between pineocytoma and pineoblastoma (
replaces atypical/aggressive pineocytoma) as per WHO 2016
update.
 Two thirds of all pineal parenchymal tumors
 Age - any age, but the peak prevalence is in early adulthood.
Slight female preponderance
 The 5-year survival is 39%–74%
 Rarely, CNS or other metastases have been reported.

35. Pathology and Histology
 On Gross , PPTID is similar in appearance to
Pineocytoma. Well-circumscribed lesion without
evidence of necrosis.
 Histology - evaluation reveals diffuse sheets of
uniform cells and the formation of small rosettes, with
features intermediate between those of pineocytoma
& pineoblastoma
 Low to moderate levels of mitotic activity and nuclear
atypia are seen.
 IHC – Positive for synaptophysin & NSE. Varying
labeling with S100, Chromogranin A.
 Two morphologic subtypes, small cell and large cell,
have been recently described.

36. Imaging Findings
 No definite imaging findings separate PPTID from pineoblastoma
or pineocytoma.
 Compared to pineocytoma, these tumors are usually larger,
demonstrate local invasion and are more heterogeneous
 Heterogeneously hypointense on T1 and hyperintense on T2 /
FLAIR
 Heterogeneous contrast enhancement
 Cystic areas may also be seen. Hemorrhage are rare.
 CSF mets may be present. Rare.

38. PPTID
 Perf and DWI can be applied to help differentiate between
grade II and III tumors, which demonstrated increased
perfusion with restricted diffusion and low ADC values in
grade III tumors.
 MRS – elevated choline, reduced NAA, lactate peak.
 DWI : Diffusion characteristics of PPTID are linked to
tumoral cellular proliferation indices; diffusion values have
been shown to vary significantly between pineocytomas
and pineoblastomas.

39. PPTID
 Consider the diagnosis of PPTID in an older child or adult with an
atypical or aggressive appearing, locally invasive pineal region mass
 Given the potential for leptomeningeal seeding, preoperative imaging of
the entire neuraxis at the time of diagnosis may be warranted
 Shorter follow up and adjuvant therapy may be indicated in selected
cases.
 The proliferative marker, MIB-1 labeling index, has been reported as a
useful tool to identify the higher grade subgroup of PPTIDs. Clinically
this distinction is critical, because grade III PPTIDs are often treated with
aggressive therapy, including craniospinal radiation, surgery.

40. Neuroimag Clin N Am
27 (2017) 85–97

41. Pineoblastoma
 Pineoblastoma (PB) is a
poorly differentiated, highly
embryonal neoplasm of the
pineal gland.
 CSF dissemination commonly
occurs (45%). The 5-year
survival is 58%
 Clinical profile: Toddler with
Parinaud syndrome and
signs/symptoms of elevated
intracranial pressure

42. Pineoblastoma
 PBs share morphologic and immunohistochemical features with
embryonic cells of the developing human pineal gland and retina.
 PBs - RB1 gene abnormalities. PBs also occur in patients with
familial (bilateral) retinoblastoma (the so-called "trilateral
retinoblastoma syndrome")
 Cases - familial adenomatous polyposis. DICER1 syndrome
 PBs comprise 0.5-1.0% of primary brain tumors, 15% of pineal
region neoplasms, and 20-35% of pineal parenchymal tumors.

43.  Prognosis is poor with a median survival of 16-25 months.
CSF dissemination is frequent at the time of initial
diagnosis and the most common cause of death.
 Treatment Options. Surgical debulking with adjuvant
chemotherapy and craniospinal radiation comprise the
typical regimen.

44. Pathology & Histology
 Highly cellular embryonal neoplasms
that resemble other PNET of CNS.
Cells have scant cytoplasm and are
arranged in diffuse sheets with
occasional Homer-Wright rosettes
(neuroblastic differentiation) or
Flexner-Wintersteiner rosettes
(retinoblastic differentiation)
 Hemorrhage or necrosis may be
present.
 On immunohistological evaluation,
increased Ki-67 labelling index
 Infiltration into adjacent structures and
craniospinal dissemination

45. Imaging
General Features:
 Location - Pineal gland; frequent extension/invasion into corpus
callosum, thalamus, midbrain, vermis
 Size - Large, mostly > 3 cm
 Morphology - Irregular, lobulated mass with poorly delineated margins
 Nearly 100% with obstructive hydrocephalus Large, heterogeneous,
aggressive pineal mass with "exploded", peripheral Ca++
 CT : large, hyperdense, inhomogeneously enhancing mass with
obstructive hydrocephalus is typical.
 MRI : PBs are heterogeneous tumors with necrosis and intratumoral
hemorrhage. Mixed iso- to hypointense on T1WI and mixed iso- to
hyperintense on T2WI . Enhance strongly but heterogeneously.
Restriction on DWI is common

46. MR Findings:
 GRE/SWI: Ca++, haemorrhage
may bloom
 DWI: Solid portion show
restricted diffusion (increased
cellularity)
 T1 C+: Moderate,
heterogeneous enhancement
 MRS: elevated choline, reduced
NAA & prominent myoinositol,
glutamate and taurine peak (3.4
ppm).
 Perfusion :

48. Comparison of imaging findings

50. Trilateral Retinoblastoma
 Presence of bilateral ocular retinoblastoma
and an intracranial, typically midline, small
cell tumor
 Intracranial tumors associated with
retinoblastoma:
 Pineoblastoma (most common)
 Suprasellar region
 Frequently have a family history
 The mean survival is up to 19 months

51. Differential diagnosis
 PB Vs PPID- PB is more aggressive, age, CSF
dissemination
 Germinomas – adolescent/young adults, engulfs
calcifications, lower ADC, rCBV, MRS- Taurine and lipid
peak, Serum and CSF markers. Coexistent suprasellar
mass
 Pineal anlage tumors - Pineal anlage tumors exhibit both
PB-like neuroectodermal and ectomesenchymal
elements. Infants and young children.

52. Diffusion characteristics of pediatric
pineal tumors : NRJ

53. Papillary Tumor of the Pineal Region
 PTPR as a distinct entity in the 2007 WHO classification, grade II
or III in 2016 update.
 Chromosome 10 losses , most common genetic alteration. Several
subcommissural organ-related genes such as transcription factor
SPDEF are overexpressed in PTPRs
 Originate from specialized ependymocytes of the subcommissural
organ located in the lining of posterior commissure.
 HPE closely resembles ependymoma & choroid plexus tumors.
(PTPRs can be distinguished from these tumors by the absence of
immunoreactivity to epithelial membrane antigen)

54. Immunopositivity for
S100 & NSE
Immunonegativity for GFAP
H&E: Papillary & solid areas
Neuropathologic description of the tumor
manifested by papillary features, rosettes, and
pseudorosettes

55. Imaging
 Well-circumscribed lesions, usually < 4cm in size. Cystic areas are
commonly present
 Variable SI on T1WI: T1 hyperintensity. Hyperintense on T2WI and
heterogenous contrast enhancement
 T1 hyperintensity is hypothesized to be related to secretory inclusions
containing protein or glycoprotein, T1 SE MTC is more effective in
detecting this peculiar hyperintensity related to PTPR
 DWI: restricted diffusion in solid areas
 MRS: high choline, reduced NAA, lactate & myoinositol peak
 Perfusion: high rCBV & rCBF.

57. T1 hyperintense pineal masses
 Teratoma, dermoid, or lipoma: T1 fat sat sequence
 Partially thrombosed aneurysm or venous malformation: CTA /
MRA
 Hemorrhagic metastasis: Susceptibility artefacts
 Melanotic melanomas will also demonstrate susceptibility
effects

58. Germ Cell Tumors
 Most tumors of the pineal gland are germ cell neoplasms, which account
for approximately 40% of all pineal tumors
 WHO classifies them into:
 Germinomas
 Non germinomatous GCTs - include teratomas, embryonal
carcinoma, yolk sac tumor, choriocarcinoma, and the mixed GCTs
 Primary intracranial GCTs arise from the pluripotent stem cell – neural
type
 All GCTs share a common molecular pathogenesis.
 activation of the mitogen-activated protein kinase (MAPK) and/or
phosphoinositide 3-kinase (PI3K) pathways, indicating that they
develop from a common ancestral cell.
 Tumor-produced oncoproteins (AFP, β-hCG, placental alk phosphatase)

59.  GCTs account for 0.5-3.5% of all brain tumors but 3-8% of
primary CNS neoplasms in children.
 Prevalence is location dependent. In Asia, GCTs cause 8-15% of
pediatric brain tumors. Western countries – 0.4 to 3.4 %.
 GCTs are generally tumors of children and young adults; 80- 90%
of patients are younger than 20 years of age.
 Germinomas represent the majority of these neoplasms, and
teratomas are the second most common
 In the pineal region, GCTs occur more frequently in males.
Germ Cell Tumors

60. Germinomas
 "hug" the midline, from the pineal gland to the
suprasellar region. Pineal – Suprasellar.
 20% of intracranial germinomas are multiple.
 Nearly all germinomas have a biphasic
pattern of abundant reactive lymphocytes—
usually dominated by T cells—intermixed with
large round germinoma cells with prominent
nucleoli
 Divided into two subtypes:
 Pure germinoma
 Germinoma with syncytiotrophoblastic
cells
 Later has decreased long-term survival
and show elevated CSF levels of hCG

61. Germinomas
 Most common intracranial GCT and accounts for 1-2% of all primary brain
tumors.
 More than 90% of patients are younger than 20 years of age
 Male : Female = 10:1 Suprasellar germinomas have no sex predilection.
 Presentation. : Pineal germinomas typically present with headache and
Parinaud syndrome. Suprasellar germinoma - central diabetes insipidus.
Visual loss and precocious puberty are other presentations.
 CSF cytology is rarely positive for tumor cells.
 Natural History. CSF dissemination and invasion are common.
 Treatment Options: radiation therapy is the standard first-line treatment.
Adjuvant chemotherapy is reserved for disseminated tumors although the
KIT/RAS and AKT1/mTOR pathways are potential therapeutic targets.

62. Imaging
CT:
Hyperdense, "engulfs" pineal Ca++ Enhances strongly, uniformly ,
Hydrocephalus may be present
MRI:
 Solid mass that may have cystic components
 T1 iso-/hypointense, T2 iso-/hyperintense
 Inflammatory germinomas may have extensive peritumoral
T2/FLAIR hyperintensity
 SWI shows Ca++, hemorrhage
 Enhances intensely, heterogeneously
 Diffusion restriction - indicative of the highly cellular nature. Low
ADC values used to monitor response to therapy.
 High perfusion – r CBV - 4.6 – 4.8
 The possibility of CSF seeding – image entire neuraxis

64. MRS:
Prominent Lipid peak,
taurine peak and
without an MI peak in
short TE MRS.

67. Differential Diagnosis
 Nongerminomatous GCT - larger than
germinomas,contain T1 hyperintense foci, enhance more
strongly, higher mean ADC values.
 PPTs (pineoblastoma, PPTID).
 Glial Neoplasms.
 Histiocytosis (stalk lesion in child)
 Neurosarcoidosis (stalk lesion in adult)

68. Teratoma
 "Misenfolded" or displaced
embryonic stem cells.
 60% of prenatally detected
parenchymal brain tumors.( 2-4%
of brain tumors)
 Differentiate along ectodermal,
endodermal, and mesodermal
lines.
 There are three types of
teratoma:
 Mature teratoma (fully
differentiated tissue)
 Immature teratoma (complex
mixture of fetal-type tissues
from all three germ layers and
mature tissue elements)
 Teratoma with malignant
transformation

69. Pathology
 Lobulated neoplasm with a complex
mixture of adult-type tissues from all
three embryonic germ layers
 Immature teratomas contain
incompletely differentiated tissue
elements that resemble fetal tissue

70. Imaging
 Multiloculated, lobulated lesion with foci of fat attenuation,
calcification, and cystic regions
 T1WI - T1 shortening due to fat and variable SI related to
calcification.
 T2WI - soft-tissue component is iso- to hypointense. The soft-
tissue component demonstrates enhancement.
 SWI is useful for calcification.
 The malignant form may have a more heterogeneous imaging
appearance, shows hemorrhage within.

73. Other GCTs
 Choriocarcinoma, yolk sac
tumors, and embryonal carcinoma
are rare neoplasms
 These neoplasms may have
imaging findings similar to those
of other germ cell neoplasms or
primary pineal neoplasms
 Evaluation of serum oncoproteins
assists in making the appropriate
diagnosis
 These lesions may also
hemorrhage, resulting in T1
shortening.

74. AJNR 33 Mar 2012

75. Pineoblastoma Germinoma
Pineoblastoma shows ADC value of
426.68 106 mm2/s.
Germinoma shows ADC value of
1500.68 106 mm2/s.

77. J Neuro onco 2016

78. Astrocytomas
 Pineal region astrocytomas may arise from:
 Splenium of the corpus callosum
 Thalamus
 Tectum of the midbrain
 Rarely, they may arise from the neuronal elements from pineal
gland
 May be circumscribed (Pilocytic, WHO grade I) or diffusely
infiltrating (WHO grades II –IV)

79. Tectal gliomas
 Usually low grade (WHO grade I or II)
 More frequently in childhood and are
slow growing
 Secondary obstruction of the aqueduct
 Isointense on T1 and hyperintense on
T2WI with no to minimal enhancement

81. Rosette forming glial neuronal tumor: Pineal region is the second
most common site. Young adults. Heterogeneous solid cystic mass
with Hemorrhage and calcifications frequent. CSF dissemination .
Imagine entire neural axis.

82. Meningioma
 Rare - approximately 6 - 8% of all pineal tumors
 ‘Pineal region meningioma’
 arising from the velum interpositum and freely lying in the pineal
region
 quadrigeminal cistern and/or in the posterior third ventricle
 falcotentorial junction
 Mean age – 40 yrs; 2:1 female predominance
 Clinically - Pupillary abnormalities and/or upward gaze paresis
are uncommon as compared to other pineal tumors

84. Lipoma
 Arise from abnormal differentiation
of the meninx primitiva
 Malformations and not neoplasms
 Blood vessels & nerves course
through them
 At CT & MR: imaging features of fat
 No enhancement

85. Metastasis
 Metastases to the pineal gland are
rare, with autopsy reports indicating
a prevalence of 0.4%– 3.8% in
patients with solid tumors.
 The most common tumors to spread
to the pineal region are those of the
lung (most frequent), melanoma,
breast, kidney, esophagus, stomach,
and colon
 Pineal metastases may be present
without metastases to the brain
parenchyma.

86. Pineal Cysts
 Asymptomatic, small sized, unilocular, benign pineal lesions
which do not show size change.
 Incidence: 0.6-10.8% of all random or consecutive brain MRI
studies and in 23% of healthy volunteers. 40% in autopsy studies
 Location: Above tectum, below ICVs
 Age: all age ranges but predominant in 40–49 yrs.
 Gender: Female predominance

87. Pineal Cysts
Etiology:
 Enlargement of embryonic pineal cavity
 Ischemic glial degeneration +/- hemorrhagic expansion
 Small pre-existing cysts which enlarge with hormonal influences
Signs/symptoms:
 Vast majority clinically silent, discovered incidentally
 Large cysts (> 1 cm) may become symptomatic
 50% headache (aqueduct compression, hydrocephalus)
 10% Parinaud syndrome (tectal compression)
 Very rare: "Pineal apoplexy" with intracystic hemorrhage, acute
hydrocephalus, sudden death

88. Pathologic and Histology
 Cyst may be uni- or multilocular,
and the wall comprises three layers
 The inner layer consists of gliotic
tissue ( hemosiderin lined), the
middle layer is composed of pineal
parenchymal tissue( with calcium)
and the outer layer is formed by
fibrocollagen layer
 The fluid in the cyst is
proteinaceous and may contain
hemorrhagic components,
influence MRI image intensity

89. Imaging of pineal cysts
 Round or oval, thin-walled, and well-circumscribed; wall thickness usually < 2 mm. 2
to 15 mm in size.
 Follow CSF signal intensity on T1 & T2WI, Not completely suppressed due to
protein contents.
 Enhancement of the cyst wall occurs in most pineal cysts but is typically incomplete
(attributed to fragmentation of the pineal parenchyma as the cyst enlarges)
 At delayed imaging, uniform enhancement of the cyst has been reported, resulting in
the appearance of a solid mass. Mechanism - passive diffusion of the contrast agent
through the cyst wall or to active secretion of contrast agent by the cyst wall.
 MR biomarkers (tectum-splenium- cyst ratio and thalamic and periventricular
edema) could be associated with central venous hypertension and severity of
symptoms in non-hydrocephalic,symptomatic PC patients.

90. Differential Diagnosis
 Pineocytomas – on immediate post contrast even cystic
PC show show nodularity and internal enhancement
 Epidermoid, Arachnoid cysts, Cystic astrocytomas
Management Issues
 Typical cyst, < 1cm no imaging, only clinical follow up
 Atypical cyst, > 1cm – Imaging follow up
 Progressive increase in size – HPE & Decompression

92. Other Pineal Region Masses
 Meningioma, ependymoma, choroid plexus
tumors, central neurocytoma, ganglioglioma,
 Epidermoid and dermoid cysts, and lipomas.
 Metastases
 Rare lesions - solitary fibrous tumor, sarcoid
lesions, and melanoma

93. Epidermoid and Dermoid Cysts
 Congenital inclusion cysts containing epithelial element
 3%–4% of intracranial epidermoid cysts occur in the pineal region
 Pineal epidermoid cysts - peak age at presentation is 3rd decade
 Dermoid cysts present in childhood or adolescence.
 Dermoid cysts increase in size by means of both desquamation and
glandular secretion, while epidermoids only by desquamation

94. Pathology
 Wall of epidermoid cysts : simple
stratified squamous epithelium, and
the cyst contents consist of layers of
keratinaceous debris
 Dermoid cysts contain dermal
appendages (hair follicles, sweat
glands)
 Both lesions slowly expand over time
and can rupture resulting in chemical
meningitis, which may be fatal

95. Imaging
 Characteristics as elsewhere in CNS
 Epidermoid - Insinuate into adjacent structures and encase
nerves and blood vessels. Akin to CSF + DWI restriction.
 Dermoid – T1 hyperintensity – lipid content with
calcfications.

97. Pineal Calcification
 On plain skull film (33-76% in adults), more frequently on C
 Usually in the form of a cluster of amorphous calcification
 Size of calcification: usually 3-5 mm, if > 1 cm, likely
pathological
 Age related increase in incidence of pineal calcifications
 0% for the first decade
 2% for the second decade
 10.5% for the third decade
 30% by the fourth to seventh decade

98. Conclusion
 Lesions of the pineal region include a diverse group of entities
 GCts and PPTS are the main pathologic entities. Common clinical and
radiological presentations
 Neoplasms may also arise from the variety of cell types residing in the
proximity of the pineal gland
 Knowledge of the variety of lesions that occur in the pineal region, their
imaging appearances, and their clinical features assists in narrowing
the radiologic differential diagnosis and optimizing patient treatment .
 Advanced imaging techniques like DWI, Perfusion , MRS help in
narrowing down the possibilities.

99. SCTIMST Cases : case 1

100. Case 2

103. CASE 3

106. Case 4

109. Q 1
Q: T1 hyperintensity seen in Papillary tumor of pineal region
(PTPR) is attributed to
A. Haemorrhage
B. Melanin
C. Secretory inclusions containing glycoprotein
D. Cyst contents

110. Q 2
Q: Entire neuraxis imaging is required in which of the
following pineal parenchymal tumors
A. Pineocytoma
B. Pineoblastoma
C. GCT
D. PTPR

111. Q 3
Q. Regarding PINEOBLASTOMA, which of the following
are true
A. Associated with chromosome 10 losses
B. Associated with DICER1 syndrome
C. Associated with RB1 gene
D. Associated with KIT/RAS and AKT1/mTOR pathways

112. Q 3
Q. Regarding CNS germinomas which of the following
statement is false
A. Synctiotrophoblastic germinomas have increased
survival
B. Chemotherapy is the standard line of treatment
C. 20% are multifocal.
D. Pineal germinomas are more common in males

113. Q 4
Q: Taurine peak is associated with which of the following
A. Germinoma
B. Pineoblastoma
C. PPTID
D. PTPR

114. Q 5
Q. Regarding Pineal cysts which of the following statement
is false
A. Follow CSF signal intensity on all sequences
B. Solid enhancement may be seen on delayed post
contrast images
C. Middle layer of the cyst wall comprises of pineal
parenchymal tissue
D. MRI biomarkers not very essential in management.

115. Q 6
Q. Papillary tumor of pineal region originate from
A. Ependymocytes of subcommisural organ
B. Pineocytes
C. Papillary metaplasia of pineal cells
D. Pineoblasts

116. Questions
yes No
Thank you