Third Eye Blind? Pearls for Differentiating Pineal Lesion ASNR 2015 eEdE-68; SN: 956 Ammar Chaudhry...
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Transcript of Third Eye Blind? Pearls for Differentiating Pineal Lesion ASNR 2015 eEdE-68; SN: 956 Ammar Chaudhry...
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+
Pineal Cyst
Case #1: Incidental finding
• 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: Non-neoplastic 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
ADC
CT C-
DWISag T1WI C+
Sag T2WI
Case #2: 12 y/o boy with emesis
• Symptomatic at diagnosis: Parinaud syndrome, headache, hydrocephalus– Elevated placental alkaline
phosphatase (PLAP)– ± Elevated β-HCG
• Incidence Highest in young male Asian patients– 90% < 20 y/o (peak: 10-12)– M:F = 10:1 in pineal region
• Histology: Similar to ovarian dysgerminoma and testicular seminoma
Germinoma
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 four-months of HA and Pineal Germinoma
NCCT T2 T1 C+
Case #3: 10 y/o boy with headache
Ax T1WI Post
Ax CT C-
Ax T2WI Sag T1WI Pre
Sag T1WI Post
• 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
• Histology: contains elements of 3 germ layers (ectoderm, mesoderm, endoderm)
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
• 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
– 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 Germ Cell Tumor (GCT)
Ax CT C-
Ax T1WI Post Ax T2WI FS
Sag T1 Pre
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
Sag FLAIR
Ax FLAIR Ax T2WI Ax T1WI C+
Sag T1WIC+
Ax CT C-
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– Peak incidence: 10-20
years– No gender predilection– Germ cell markers
negative• Histology: Composed of
small, uniform, mature cells that resemble pineocytes
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
DWI
Sag T1WI C+Sag T1WI
Ax T2WI ADCAx CT C-
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 mitotic figures
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
DWI
Sag T1WI Pre
Ax T1WI PostAx T2WI
ADC
• Aggressive symptomatic mass– Hydrocephalus– Headache, nausea, vomiting,
lethargy– Papilledema, abducens nerve
palsy– Parinaud syndrome, ataxia
• Mean age at diagnosis: 3 years– F:M = 2:1– Germ cell markers negative
• Histology: Highly malignant primitive neuroectodermal tumor (PNET) derived from embryonic precursors of pinealocytes
Pineoblastoma
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
Ax T1WI PostAx T2WI Sag T1WI Post
Ax CT C- Ax CT C+
• Combination of bilateral retinoblastoma and midline intracranial neuroblastic mass– 80% pineal, 20% suprasellar– Represents 5-15% of familial lesions;
rarely sporadic cases– Quadrilateral (tetralateral) = bilateral
Rb plus pineal AND suprasellar masses
• 90-95% diagnosed by age 5 years– Sporadic (nongermline): 60%– Inherited (germline): 40%– Prognosis <24 months
• Histology: Primitive neuroectodermal tumor (PNET)
“Trilateral” Retinoblastoma
• Circumscribed (pilocytic) or diffusely infiltrating
• MRI:– T1: isointense– T2/FLAIR:
hyperintense – T1C+: variable
enhancement• Histology: Typically
low grade
Case #8: 28 y/o male with long standing stable pineal mass
Sag T1WI Post Ax FLAIR Ax CT C-
Tectal Astrocytoma
Sag T1WI Post
Case #9: 51 y/o woman presented after an episode of severe headache and memory loss
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
Sag T1WI Post AX T1WI Pre Ax FLAIR Ax T2WI
Case #10: 43 y/o female with vertigo
• 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
Pineal Lipoma Sag T1WI FS Post AX T1WI Pre Ax T2WI Sag T1WI Pre
12 year old girl p/w HA, blurry vision, diplopia, N/V x 4 days
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 enhancementDWI: no reduction
DDx: Epidermoid cyst
Ax FLAIR Sag T2WI Ax CT C- ADC
19 year old male with progressive HA and ataxia x 1month
• Benign squamous epithelial cyst with dermal elements• Midline fat-containing unilocular cystic lesion• Suprasellar most common location• Rupture can cause chemical meningitis– Subarachnoid lipid droplets– Fat-fluid level in ventricles• CT
– hypodensity (lipid)– fat-fluid level in cyst • MRI
– T1W: hyperintense (lipid)– T2W: heterogeneous– signal drop with fat suppression
• DDx: epidermoid cyst, craniopharyngioma, teratoma, lipoma
Dermoid Cyst Ax T2WI Ax CT C- Sag T1WI Pre
40 year old male presents following seizure
• Ectodermal inclusions • Intradural (90%), primarily in basal cisterns• Extradural (10%): skull and spine• Lobulated cauliflower-like mass with “fronds”
– Insinuates cisterns and encases neurovascular structures
• Chemical meningitis and CSF seeding with rupture• CT
– > 95% hypodense (CSF-like); rare "dense" variant
• MRI– 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
Epidermoid Cyst
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