1. NON-NEUROEPITHELIAL TUMORS
R.Rengarajan

2. WHO classification
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Tumors of the Sellar Region
Hematopoietic tumors
Germ Cell Tumors
Tumors of the Meninges
Non-menigothelial tumors of the meninges
Tumors of Cranial and Spinal Nerves
Local Extensions from Regional Tumors
Metastatic tumours
Unclassified Tumors
Cysts and Tumor-like Lesions

3. • Tumors of the Sellar Region
– Pituitary adenoma
– Pituitary carcinoma
– Craniopharyngioma

4. • Hematopoietic tumors
– Primary malignant lymphomas
– Plasmacytoma
– Granulocytic sarcoma
– Others

5. • Germ Cell Tumors
– Germinoma
– Embryonal carcinoma
– Yolk sac tumor (endodermal sinus tumor)
– Choriocarcinoma
– Teratoma
– Mixed germ cell tumors

6. • Tumors of the Meninges
– Meningioma
• variants: meningothelial, fibrous
(fibroblastic), transitional
(mixed), psammomatous, angiomatous, microcystic, sec
retory, clear cell, chordoid, lymphoplasmacyte-rich, and
metaplastic subtypes
– Atypical meningioma
– Anaplastic (malignant) meningioma

7. • Non-menigothelial tumors of the meninges
– Benign Mesenchymal
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osteocartilaginous tumors
lipoma
fibrous histiocytoma
others
– Malignant Mesenchymal
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chondrosarcoma
hemangiopericytoma
rhabdomyosarcoma
meningeal sarcomatosis
others
– Primary Melanocytic Lesions
• diffuse melanosis
• melanocytoma
• maliganant melanoma
– variant meningeal melanomatosis
– Hemopoietic Neoplasms
• malignant lymphoma
• plasmactoma
• granulocytic sarcoma
– Tumors of Uncertain Histogenesis - hemangioblastoma

8. • Tumors of Cranial and Spinal Nerves
– Schwannoma (neurinoma, neurilemoma)
• cellular, plexiform, and melanotic subtypes
– Neurofibroma
• circumscribed (solitary) neurofibroma
• plexiform neurofibroma
– Malignant peripheral nerve sheath tumor (Malignant
schwannoma)
• epithelioid
• divergent mesenchymal or epithelial differentiation
• melanotic

9. • Local Extensions from Regional Tumors
– Paraganglioma (chemodectoma)
– Chordoma
– Chondroma
– Chondrosarcoma
– Carcinoma

10. Primary CNS lymphoma
• Malignant primary CNS neoplasm composed of B lymphocytes
• Enhancing lesion(s) within basal ganglia, periventricular WM
• 90% supratentorial
• Frontal and parietal lobes most common
• Deep gray nuclei commonly affected
• Lesions cluster around ventricles, GM-WM junction
• Often involve, cross corpus callosum
• Frequently abut, extend along ependymal surfaces

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NECT
Hyperdense classically
May be isodense
+/- Hemorrhage, necrosis (immunocompromised)
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CECT
Common: Moderate, uniform (immunocompetent)
Less common: Ring (immunocompromised)
Rare: Nonenhancing (infiltrative, mimics white matter disease)

12. • MR Findings
• T1WI
• Immunocompetent: Homogeneous isointense/hypointense to cortex
• Immunocompromised: Isointense/hypointense to cortex
– May be heterogeneous from hemorrhage, necrosis
• T2WI
• Immunocompetent: Homogeneous isointense/hypointense to cortex
– Hypointensity related to high nuclear to cytoplasmic ratio
• Immunocompromised: Isointense/hypointense to cortex
– May be heterogeneous from hemorrhage, necrosis
– Ca++ may rarely be seen, usually after therapy
• Mild surrounding edema is typical

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FLAIR
Immunocompetent: Homogeneous isointense/hypointense to cortex
Immunocompromised: Isointense/hypointense
May be hyperintense
Mild surrounding edema is typical
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T2* GRE: May see blood products or calcium as areas of "blooming" (immunocompromised)
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DWI: Restricted diffusion, low ADC map reported
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T1 C+
Immunocompetent: Strong homogeneous enhancement
Immunocompromised: Peripheral enhancement with central necrosis or homogeneous
enhancement
Nonenhancement extremely rare
Lymphomatous meningitis is typically related to systemic disease
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MRS
NAA decreased, Cho elevated
Lipid and lactate peaks reported
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MR perfusion: Early studies show increased rCBV

16. Angiocentric lymphoma
• Rare malignancy characterized by intravascular proliferation of lymphoid
cells with a predilection for CNS and skin
• A form of non-Hodgkin lymphoma (NHL) characterized by angiotropic
growth
• Multifocal abnormal T2 hyperintensity in deep WM, cortex or basal ganglia
+ enhancement
• Supratentorial (periventricular/deep WM, G-W junction)
• May involve basal ganglia (BG), midbrain
• NECT: Focal, bilateral asymmetric low density lesions inWM, cortex, or
basal ganglia
• CECT: Variable (none to moderate)

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T1 WI
Multifocal hypointense lesions
May see blood products
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T2WI
45% hyperintensities in deep WM (edema, gliosis)
36% cortex hyperintensity, infarct-like lesions
May see hemorrhagic transformation
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T2* GRE: May see blood products "blooming“
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DWI: Diffusion restriction reported
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T1 C+
Variable enhancement: Linear, punctate, patchy, nodular, ring-like, gyriform, homogeneous
o Meningeal and/or dural enhancement

20. Germinoma
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Morphologic homologues of germinal neoplasms arising in the gonads and
extragonadal sites
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Pineal region mass that "engulfs" the pineal gland
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Midline near the 3rd ventricle - 80-90% (Pineal region - 50-65%, Suprasellar - 2535%, Basal ganglia and thalami - 5-10%)
NECT
• Sharply circumscribed dense mass (hyperdense to GM)
• Pineal: Mass drapes around posterior 3rd ventricle or "engulfs" pineal gland
• Suprasellar: Retrochiasmatic, non-cystic, non -calcified
• ± Hydrocephalus
CECT
• Strong uniform enhancement, ± CSF seeding
• Cystic/necrotic/hemorrhagic components not uncommon with larger germinomas
(especially in basal ganglia)

21. • T1Wl
• Isointense or hyperintense to GM
• Early cases may only show absent posterior pituitary bright spot
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T2Wl
Iso-to-hyperintense to GM (high nuclear:Cytoplasmic ratio)
Cystic or necrotic foci (high T2 signal)
Less common: Hypointense foci (hemorrhage)
• FLAIR: Slightly hyperintense to GM
• T2* GRE: Calcification, hemorrhage (rare)
• DWI: Restricted diffusion due to high cellularity
• T1 C+: Strong, homogeneous enhancement, ± CSF seeding, ± brain
invasion
• MRS: inc Choline, dec NAA, ± lactate

25. Teratoma
• Tridermal mass originating from displaced embryonic tissue that is
misenfolded
• Midline mass containing: Ca++, soft tissue, cysts, and fat
• Hugs midline, optic chiasm, pineal gland (Majority are
supratentorial)
• NECT: Fat, soft tissue, Ca++, cystic attenuation
• CECT: Soft tissue components enhance

26. MR Findings
• T1WI: inc signal from fat, variable signal from Ca++
• T2WI: Soft tissue components iso- to hyperintense
• FLAIR: dec signal from cysts, inc signal from solid tissue
• T2* GRE: dec signal from Ca++
• T1 C+: Soft tissue enhancement
• MRS: inc lipid moieties on short echo

29. Embryonal carcinoma
• Malignant tumor composed of undifferentiated cells
• Heterogeneous pineal or suprasellar mass in adolescent
• Hugs midline as other CNS GCTs
• Typically well circumscribed or lobulated
• NECT – Heterogenous - Isoattenuating to hyperattenuating
• CECT - Enhancing, ± cysts, hemorrhage

30. T1WI
• Hypointense to isointense to GM
• T1 shortening due to protein, blood or fat
T2WI: Isointense to slightly hyperintense to GM
FLAIR
• Hyperintense solid elements
• ± Hydrocephalus
T2* GRE: Dephasing from hemorrhagic foci
DWI: ± Restriction within solid components
T1 C+: Heterogeneous enhancement, ± CSF spread
MRS: inc Choline, inc lipid and lactate, dec NAA

33. Meningioma
• WHO grade 1 Meningioma
• Dural-based enhancing mass w/cortical buckling & trapped CSF
clefts/cortical vessels
• Supratentorial (90%): Para sagittal/convexity (45%), sphenoid ridge (1520%), olfactory groove (5-10%), parasellar (5-10%)
• Infratentorial (8-10%): CPA most common
• Misc inside the dural: Intraventricular, optic nerve sheath, pineal region
• Misc outside the dura: Paranasal sinus (most common), nasal
cavity, parotid, skin, calvarium

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NECT
Hyperostosis, irregular cortex, tumoral calcifications, inc vascular markings
Sharply circumscribed smooth mass abutting dura
Hyperdense (70-75%), iso- (25%), hypo- (1-5%)
Calcified (20-25%): Diffuse, focal, sandlike, sunburst, globular, rim
Necrosis, cysts, hemorrhage (8-23%)
Rare lipoblastic subtype
Brain cysts & trapped pools of CSF common
Peritumoral hypodense vasogenic edema (60%)
• CECT: > 90% enhance homogeneously & intensely
• CTA: May complement DSA in defining vascular supply to tumor & normal
tissues from each feeder artery before embolization

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T1WI
Usually iso- to slightly hypointense with cortex
Necrosis, cysts, hemorrhage (8-23%)
Best to visualize gray matter "buckling“
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T2WI
Variable; sunburst pattern may be evident
Necrosis, cysts, hemorrhage (8-23%)
Best to visualize trapped hyperintense CSF clefts (80%) & vascular flow
voids (80%)
• FLAIR: Hyperintense peritumoral edema, dural "tail“
• T2* GRE: Best sensitivity for calcification
• DWI: DWI, ADC maps for CM variable in appearance

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T1 C+
> 95% enhance homogeneously & intensely
Dural "tail" (35-80% of cases ): Non-specific
En plaque: Sessile thickened enhancing dura
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MRV: Evaluate possible sinus involvement
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MRS
Elevated levels of Alanine at short TE
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Reported peak ranges from 1.3-1.5 ppm
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Perfusion MRI: Good correlation between volume transfer constant (K-trans) &
histologic grade

40. Atypical and malignant meningioma
Common meningioma = WHO grade 1 meningioma
Atypical meningioma = WHO grade 2 meningioma
Malignant meningioma = WHO grade 3 meningioma
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Dural based lesion locally invasive with areas of necrosis & marked brain edema
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Occur anywhere along neuraxis
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AM: Para sagittal (44%), cerebral convexities (16%)
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NECT
Hyperdense w/minimal or no calcification
Marked perifocal edema & bone destruction
CT "Triad" of MM: Extracranial mass, osteolysis, & intracranial tumor
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CECT
Enhancing tumor mass
Prominent pannus or tumor, extending away from mass termed "mushrooming"

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T1WI
Indistinct tumor margins
Extending tumor interdigitating with brain
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FLAIR:Marked peritumoral edema
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DWI
Markedly hyperintense on DWI
Marked decrease in ADC
Correlates with histopathology
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T1 C+
Enhancing tumor mass
Plaque like & may extend into brain, skull, scalp
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MRV: Evaluate possible sinus involvement
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MRS - Elevated levels of Alanine at short TE
Reported peak ranges from 1.3-1.5 ppm

45. Hemangioblastoma
• Vascular neoplasm of uncertain histogenesis
• Adult with intra-axial posterior fossa mass with cyst, enhancing mural
nodule abutting the pia
• 90-95% posterior fossa ( 80% cerebellar hemisphere )
• 60% cyst with mural nodule ( 40% solid )
• NECT – low density cyst with isodense mural nodule
• CECT – Nodule enhances intensely, Cyst wall doesn’t enhance
• CTA – may demostrate arterial feeders

46. T1 WI
• Nodule isointense with brain
• Cyst moderately hyperintense to CSF
T2 WI
• Both nodule and cyst are hyperintense
• Prominent flow voids in some cases
FLAIR
• Both cyst and nodule hyperintense
T1 C+
• Nodule enhances intensely
• Solid enhancement pattern less common
• Cyst wall enhancement very less common
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20-40 % HGBL occur in VHL patients (multiple tumors)
With visceral cysts, RCC

50. Hemangiopericytoma
• Sarcoma related to neoplastic transformation of pericytes
• Lobular enhancing extra-axial mass with dural attachment +/- skull
erosion
• Supratentorial – occipital region most common
• NECT – hyperdense extra-axial mass with surrounding
edema, calvarial erosion
• CECT – strong heterogenous enhancement
No Ca++ or hyperostosis

51. • T1 WI
• Heterogenous mass, isointense to gray matter
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T2 WI
Heterogenous isointense mass
Prominent flow voids are common
Surrounding edema, mass effect are common
Hydrocephalus
• T1 C+
• Marked heterogenous enhancement
• Dural tail seen in 50%
• MRV – occlusion of venous sinuses
• MRS – elevated myoinositol

52. • Local recurrence common, 50-80%
• Extracranial metastases common, up to 30%
• Commonly liver, lungs, lymph nodes, bones
Staging, Grading or Classification Criteria
• WHO grade II or III (anaplastic)

56. Thank you