Transcript Session eEdE-68-3274

Third Eye Blind?
Pearls for Differentiating Pineal Lesion
ASNR 2015
eEdE-68; SN: 956
Ammar Chaudhry MD; Robert Shroyer MD; Alexander Filatov MD; Robert Peyster MD; Lev
Bangiyev DO
Disclosures
• None
What is the Pineal Gland?
• Functions:
1. Neuroendocrine: melatonin synthesis
- Regulated by sympathetic input
2. Biological rhythms (e.g. circadian, puberty)
• Histologically: pineocytes (95%) and
astrocytes (5%) separated by fibrovascular
stroma
• No blood brain barrier  enhances
Why is the Pineal the “Third Eye”?
• Similar Embryologic Development
– Evaginates from caudal aspect of third ventricular
roof during 7th week of gestation
– Similar to the optic vesicles
• Retains photosensitivity in lower vertebrates
– No longer photosensitive in mammals
• Humans: accessory optic pathway
– Retinohypothalamic tract  reticulo-activating
system  autonomic function
Quadreminal Cistern Anatomy
http://mystatdx.com
Pineal Region Anatomy on T2 MRI
http://mystatdx.com
Pineal Region Mass DDX
• Germ Cell Tumors (60%)
– Germinoma (40%)
– Teratoma (15%)
– Malignant GCT NOS
• Pineal Parenchymal Tumors (15%)
– Pineocytoma (7%) – WHO Grade I
– Pineal Parenchymal Tumor of
Intermediate Differentiation (PPTID)
(3%)
– Pineoblastoma (6%) – WHO Grade IV
– Trilateral Retinoblastoma
• Neoplasms of Adjacent Tissues
– Astrocytoma (e.g. Tectal Plate Glioma)
– Meningioma
– Lymphoma
• Papillary Tumor of the Pineal Region
• Non-neoplastic
–
–
–
–
–
–
–
–
–
Pineal Cyst
Lipoma
Arachnoid Cyst
Dermoid /Epidermoid
Vein of Galen
Malformation
Neurocysticercosis
Neurosarcoid
Medial Atrial
Diverticulum of Lateral
Ventricle
Cavum Velum
Interpositum
Case #1: 11 y/o girl with migraine HA
T1WI
T2WI
T1 C+
Case #1: Incidental finding
Pineal Cyst
• Typically clinically silent
– Rarely symptomatic
when large of
hemorrhage (5%)
• Incidence among
women between 21-30
years higher than any
other group; F:M = 3:1
• Histology: Nonneoplastic glial-lined
protienaceous cyst
Pineal Cyst Pearls
• CT:
– Isodense to slightly hyperdense c/w CSF
– Mural calcification (25%),
– Multicystic/septated (20-25%)
• MRI: Incidental finding in 1-5% of MRIs
– T1: Isointense (40%) to slightly hyperintense
(60%) c/w CSF
– T2: Isointense to slightly hyperintense c/w
CSF
– FLAIR: Does not fully suppress
– DWI: Typically no restriction
– T1 C+: 90% enhance
• Usually thin rim; nodular/irregular less
common
• May demonstrate progressive fill-in
• DDx: Pineocytoma, Epidermoid cyst,
Arachnoid cyst
Case #2: 12 y/o boy with emesis
Germinoma
• Symptomatic at diagnosis:
Parinaud syndrome,
headache, hydrocephalus
– Elevated placental alkaline
phosphatase (PLAP)
Sag T1WI C+– ± Elevated β-HCGDWI
• Incidence Highest in young
male Asian patients
– 90% < 20 y/o (peak: 10-12)
– M:F = 10:1 in pineal region
CT C-
• Histology: Similar to ovarian
dysgerminoma and
testicular seminoma
Sag T2WI
ADC
Germinoma Pearls
• 80-90% in midline by 3rd ventricle
– Pineal region (50-65%)
– Suprasellar (25-35%)
– Basal ganglia/thalami (10%)
• CT:
– “Engulfs” pineal calcification
– High cellularity  hyperdense c/w grey matter
– When large become cystic, necrotic, and/or
hemorrhagic
• MR:
– High cellularity  T2 hypointense c/w gray
matter
– DWI: restricted diffusion
– T1 C+: Avid homogeneous enhancement
– Look for leptomeningeal seeding and brain
invasion
– Image entire spine before surgery
• DDx: Non-germinomatous GCTs,
pineoblastoma
9 y/o boy with fourmonths of HA and
Pineal Germinoma
NCCT
T2
T1 C+
Case #3: 10 y/o boy with headache
• Teratoma
• Congenital midline mass
– Large mass →
Macrocephaly
– Pineal origin →
Perinaud’s
– Increased serum
carcinoembryonic
antigen (CEA)
– May rupture and
cause chemical
meningitis
• Most common in male
Asians
Ax CTcontains
C• Histology:
elements of 3 germ
layers (ectoderm,
mesoderm, endoderm)
Ax T2WI
Sag T1WI Pre
Ax T1WI Post
Sag T1WI Post
Teratoma Pearls
• Suprasellar or pineal in origin
– Origin indeterminate in ~50%
• CT:
– Heterogeneous mixture of calcification,
soft tissue, multilocular cysts, and fat
• MRI:
– High cellularity  T2 hypointense c/w
gray matter
– DWI: Restricted diffusion in solid
components
– T1 C+: Solid component enhances
• WHO: mature (cystic), immature,
malignant
• DDx: craniopharyngioma, dermoid,
germinomatous GCT, pineoblastoma
20 year old male p/w HA, double vision, and N/V x
2 months; slightly elevated HCG and AFP
Malignant Germ Cell Tumor (GCT)
• Choriocarcinoma: β-hCG  hemorrhage (T1 can
mimic fat)
• Endodermal sinus tumor: α-fetoprotein (AFP)
• Embryonal cell carcinoma: β-hCG and AFP
• Difficult to differentiate from other CNS GCTs on
imaging
• Visual/endocrine symptoms, Parinaud syndrome
• Signs of hypothalamic/pituitary dysfunction
• +/- hydrocephalus
• Female predominance in suprasellar cases
• Locally invasive with metastatic potential
• Malignant GCTs often histologically mixed
Ax CT C-
Sag T1 Pre
Ax T1WI Post
Ax T2WI FS
– May exist with both germinomatous, other
nongerminomatous GCTs
– Prognosis correlated with most malignant component
• Prognosis
– Median survival < 2 years
– 5-year survival rate < 25%
• Surgical resection → chemotherapy → neuraxis
radiation
• Combination of pre- and post-irradiation
chemotherapy: Improved survival
Malignant GCT
• Heterogeneous midline lesions composed of
undifferentiated cells (serum/CSF markers)
– Soft tissue ± hemorrhage, cysts, fat
– Pineal and suprasellar most common
• Seen in late adolescents (around puberty): peak = 10-15 y/o
– M:F = 14:1 for purely pineal lesions
– More common in Asians
• Includes: embryonal carcinoma, yolk sac tumor,
choriocarcinoma, teratoma with malignant transformation,
and mixed GCT
– Can have variable leptomeningeal spread
– Heterogeneous enhancement with reduced diffusion in solid
components (cellularity)
• DDx: dermoid, other GCT, pineoblastoma
Case #4: 21 y/o male with worsening headaches x 1
year and new nausea, blurry vision
Pineocytoma
•
Stable or slow growing
– Symptoms: HA,
Parinaud’s, increased
ICP, ataxia,
hydrocephalus, mental
status changes
•
•
Mean age at diagnosis:
35 years
Sag FLAIR
Sag T1WIC+
– Peak incidence: 10-20
years
– No gender predilection
– Germ cell markers
negative
Histology: Composed of
small, uniform, mature
cells that resemble
Ax CT Cpineocytes
Ax FLAIR
Ax T2WI
Ax T1WI C+
Pineocytoma Pearls
• WHO grade I
– 100% 5-year survival
• CT
–
–
–
–
Well circumscribed, typically <3 cm
Isodense to hypodense
Peripheral "exploded" pineal calcifications
Can be cystic with occasional hemorrhage
• MRI
– T1W: Isointense to hypointense c/w gray
matter
– T2W/FLAIR: Hyperintense c/w gray matter
– T1C+: solid, rim, nodular
• DDx: Pineal cyst, PPTID, pineoblastoma,
GCT
Case #5: 32 y/o male with severe
headache and gait instability
PPTID
• Intermediate in
malignancy between
pineocytoma and
pineoblastoma
• Primary adult
parenchymal
neoplasm
• Histology:
Dysplastic, atypical
pineocytes with
variable number of
mitoticAxfigures
CT C-
Sag T1WI
Ax T2WI
Sag T1WI C+
DWI
ADC
Pineal Parenchymal Tumor of
Intermediate Differentiation
• WHO grade II or III, depending on number of mitotic figures
– Infiltrate adjacent structures (e.g., ventricles, tectum, thalamus)
– Local recurrence common
– Leptomeningeal dissemination rare
• CT
– Hyperdense due to increased cellularity
– “Engulfs” pineal calcification
• MR
–
–
–
–
T1: Mixed isointense and hypointense c/w gray matter
T2/FLAIR: Isointense c/w gray matter; small cystic foci
DWI: Not diffusion restricting
T1C+: Strong, heterogeneous enhancement
• DDx: GCT, pineocytoma, pineoblastoma
Case #6: 3 y/o boy with lethargy and
emesis for 1 ½ months
Pineoblastoma
• Aggressive symptomatic mass
– Hydrocephalus
– Headache, nausea, vomiting,
lethargy
– Papilledema, abducens nerve
palsy
– Parinaud syndrome, ataxia
• Mean age at diagnosis: 3 years
Ax T2WI
Ax T1WI Post
DWI
ADC
– F:M = 2:1
– Germ cell markers negative
• Histology: Highly malignant
primitive neuroectodermal
tumor (PNET) derived from
Sag precursors
T1WI Pre of
embryonic
pinealocytes
Pineoblastoma
• WHO grade IV
– Median survival 16-25 months
– Frequent brain invasion
• Corpus callosum, thalamus, midbrain, vermis
• CT
– Large, heterogeneous mass with poorly defined margins
– solid component hyperdense
– peripheral “exploded”calcifications
• MRI (heterogeneous with necrosis/hemorrhage)
– T1W: isointense to hypointense c/w gray matter
– T2W: isointense to hypointense c/w gray matter
– DWI: Restricted
– T1W+: variable heterogeneous enhancement
• Frequent (15-45%) leptomeningeal seeding
– Image entire spine preoperatively
• DDx: GCT, pineocytoma, astrocytoma
Case #7: 4 y/o girl with congenital bilateral
retinoblastomas p/w severe HA and vomiting x 4d
“Trilateral” Retinoblastoma
• Combination of bilateral
retinoblastoma and midline
intracranial neuroblastic mass
– 80% pineal, 20% suprasellar
– Represents 5-15% of familial
lesions; rarely sporadic cases
– Quadrilateral (tetralateral)
Ax CT C- =
bilateral Rb plus pineal AND
suprasellar masses
• 90-95% diagnosed by age 5 years
– Sporadic (nongermline): 60%
– Inherited (germline): 40%
– Prognosis <24 months
Ax CT C+
• Histology: Primitive
neuroectodermal tumor (PNET)
Sag T1WI Post
Ax T2WI
Ax T1WI Post
Case #8: 28 y/o male with long
standing stable pineal mass
Tectal Astrocytoma
• Circumscribed
(pilocytic) or
diffusely infiltrating
• MRI:
Ax CT C- Sag T1WI Post
Ax FLAIR
– T1: isointense
– T2/FLAIR:
hyperintense
– T1C+: variable
Sag T1WI Post
enhancement
• Histology: Typically
low grade
Case #9: 51 y/o woman presented after an
episode of severe headache and memory loss
Ax T2WI
Ax FLAIR
AX T1WI Pre
Sag T1WI Post
Papillary Tumor of the Pineal Region
•
•
•
Primary tumor of adults
MRI:
– T1W: can be heterogeneously hyperintense
– T2W/FLAIR: heterogeneously isointense to hyperintense; can have cystic regions
– T1W+: moderate heterogeneous enhancement
Histology: specialized ependymocytes of the subcommissural organ or ependymal
cells of pineal recess
Case #10: 43 y/o female with vertigo
AX T1WI Pre
Ax T2WI
Sag T1WI Pre
Sag T1WI FS Post
Pineal Lipoma
•
•
Typically asymptomatic
Congenital malformation of meninx primitive
– Associated anomaly of corpus callosum, cephalocele, or spinal dysraphism in 1/3 cases
•
Lobulated midline extra-axial mass with fat attenuation/intensity across
modalities/sequences
– No enhancement
– Variable calcification
– May encase vessels and cranial nerves  resection difficult
•
Histology: Mature non-neoplastic adipose tissue
12 year old girl p/w HA, blurry vision,
diplopia, N/V x 4 days
Ax CT C-
Sag T2WI
Ax FLAIR
ADC
Arachnoid Cyst
• Intra-arachnoid CSF-filled cyst
• Exerts mass effect
• No communication with
ventricular system
• Any age; M:F = 3-5:1
• Incidental finding on 2% of scans
CT: isodense c/w CSF (unless hemorrhage)
MR
T1W/T2W/FLAIR: isointense c/w CSF
(unless hemorrhage)
T1W+: no enhancement
DWI: no reduction
DDx: Epidermoid cyst
19 year old male with progressive HA
and ataxia x 1month
Ax CT C-
Sag T1WI Pre
Ax T2WI
Dermoid Cyst
• Benign squamous epithelial cyst with dermal elements – hypodensity (lipid)
– fat-fluid level in cyst
• Midline fat-containing unilocular cystic lesion
• MRI
• Suprasellar most common location
– T1W: hyperintense (lipid)
• Rupture can cause chemical meningitis
–
–
• CT
Subarachnoid lipid droplets
Fat-fluid level in ventricles
–
–
•
T2W: heterogeneous
signal drop with fat suppression
DDx: epidermoid cyst, craniopharyngioma,
teratoma, lipoma
40 year old male presents following
seizure
Epidermoid Cyst
•
•
•
•
Ectodermal inclusions
Intradural (90%), primarily in basal cisterns
Extradural (10%): skull and spine
Lobulated cauliflower-like mass with “fronds”
–
•
•
> 95% hypodense (CSF-like); rare "dense" variant
MRI
–
–
–
–
–
Insinuates cisterns and encases neurovascular
structures
Chemical meningitis and CSF seeding with rupture
CT
–
•
•
T1W: typically slightly hyperintense c/w CSF (75%)
T2W: isointense (65%) to slightly hyperintense (35%)
c/w CSF
FLAIR: usually incomplete nulling
T1W+: minimal rim enhancement (25%)
DWI: markedly reduced
DDx: arachnoid cyst, neurocysticercosis, cystic
neoplasm, dermoid cyst
References
1.
2.
3.
4.
5.
6.
7.
Mano H, Fukada Y. A median third eye: pineal gland retraces
evolution of vertebrate photoreceptive organs. Photochem
Photobiol. 2007 Jan-Feb;83(1):11-8.
Smirniotopoulos JG, Rushing EJ, Mena H. Pineal region masses:
differential diagnosis. Radiographics. 1992 May;12(3):577-96.
Smith AB, Rushing EJ, Smirniotopoulos JG. From the archives of
the AFIP: lesions of the pineal region: radiologic-pathologic
correlation. Radiographics. 2010 Nov;30(7):2001-20.
Osborn AG. Diagnostic Neuroradiology: A Text/Atlas. Elsevier
Health Sciences. 1994.
Yousem DM, Grossman RI, Zimmerman RD. Neuroradiology : The
Requisites, 3rd Edition. Elsevier Health Sciences. 2010.
Chang AH, Fuller GN, Debnam JM, Karis JP, Coons SW, Ross JS,
Dean BL. MR imaging of papillary tumor of the pineal region. AJNR
Am J Neuroradiol. 2008 Jan;29(1):187-9.
Amirsys STATdx