Chapter 5 - Central Nervous System Neoplasm and Tumor-like Masses Flashcards
1
Q
Clinical presentations of CNS neolplasm. (3)
A
- Headaches
- Seizures
- Focal neurological deficits
2
Q
Study of choice for the evaluation of a patient with intracranial neoplasm.
A
Contrast- enhanced brain MRI
3
Q
Basic sequences of MRI for evaluation of intracranial neoplasm (4)
A
- DWI
- T2WI (with FLAIR)
- T2*-weighted imaging (GRE or SWI)
- Pre/postcontrast T1WI
Advance options:
- Perfusion-weighted imaging
- MR spectroscopy
4
Q
Restricted diffusion in DWI may be seen in what cases? (3)
A
- Acute stroke
- Hypercellar tumors (lymphoma)
- Highly viscous fluids
5
Q
This measures cerebral blood volume (CBV) as a noninvasive marker of tumor vascularity, which usually increases with tumor grade
A
MR perfusion
6
Q
This measures chemical shift of nonwater molecules in a region of interest (single or multi voxel) as a noninvasive marker of tumor metabolism.
A
MR spectroscopy
7
Q
The chemical or frequency shift (in MRS) is measured how?
A
It is measures in parts per million (ppm), calibrated relative to tetramethysilane (TMS)
8
Q
In a normal brain, what are the main metabolites and their respective peaks? (3)
A
- Choline - 3.2 ppm
- Creatine - 3.0 ppm
- N-acetylaspartate - 2.0 ppm
9
Q
What choline/creatine ratio is suggestive of a high grade tumor?
A
Choline/creatine ratio >2
10
Q
Uses of PET in CNS tumor
A
Distinguishing residual/recurrent tumor from radiation-induced changes in the white matter.
11
Q
Tumors that metastasize to the brain that causes hemorrhage. (6)
A
- Melanoma
- Renal cell carcinoma
- Choriocarcinoma
- Thyroid carcinoma
- Breast carcinoma
- Bronchogenic carcinoma (lung)
(MR CT BB)
12
Q
Calcified intracranial masses. (6)
A
- Craniopharyngioma
- Astrocytoma, aneurysm
- Chorid plexus tumor
- Oligodendroglioma (>50%)
- Meningioma
- Ependymoma
(CA COME)
13
Q
Vascularized granulation tissue develops within how many hours following surgery and enhances after administration of contrast.
A
48 to 72 hours
The ideal time to obtain a post-operative contrast-enhanced study (usually MR)
14
Q
These tumors account for the majority of all gliomas
A
Astrocytoma
approximately 75%
15
Q
Astrocytomas and gliomas are divided into two major groups based on growth pattern.
A
- Circumscribed
2. Diffuse
16
Q
These gliomas demonstrate more well-defined margins on micrscopic examination and tend to be more amendable to a surgical cure.
A
Circumscribed gliomas
- Lower grade and younger age
17
Q
These gliomas demonstrate more ill-defined margins on microscopic examination, regardless of the macroscopic appearance on cross-sectional imaging.
A
Diffuse or infiltrative
18
Q
Most common pediatric CNS tumor
A
Pilocytic astrocytoma
19
Q
Most common location of pilocytic astrocytoma
A
- Cerebellum (60%)
followed by the:
- Optic pathways/ hypothalamus (30%)
- Brainstem
20
Q
Most common age group of pilocytic astrocytoma
A
Children (<20 years old)
21
Q
True or fase
Pilocytic astrocytoma is associated with neurofibromatosis type 1
A
True
22
Q
A circumscribed astrocytoma that is less common and more aggressive variant of pilocytic astrocytoma
A
Pilomyxoid astrocytoma
Most commonly occures in the suprasellar region
23
Q
A circumscribed astrocytoma that is slow-growing tumor located at the foramen of Monro and is associated with tuberous sclerosis
A
Subependymal giant cell astrocytoma
24
Q
A circumscribed astrocytoma that is peripherally located cerebral tumor that often involves the cortex/ meninges.
A
Pleomorphic xanthoastrocytoma
25
Imaging pattern of circumscribed astrocytoma
1. Circumscribed enhancing mass,
| 2. which may be accompanied by internal or adjacent fluid-filled cysts.
26
Classic appearance of a pilocytic astrocytoma in a child
Nonenhancing cyst with enhancing mural nodule in the cerebellum
27
This is a low-grade astrocytic tumor with low-level proliferative activity.
Diffuse astrocytoma
28
Astrocytic tumor with increased cellularity, mitotic activity, or nuclear atypia
Anaplastic Astocytoma
29
WHO genetically divides diffuse gliomas into: (2)
1. Isocitrate dehydrogenase (IDH) mutant
| 2. Isocitrate dehydrogenase (IDH) wildtype
30
Which has better prognosis:
A. Isocitrate dehydrogenase (IDH) mutant
B. Isocitrate dehydrogenase (IDH) wildtype
A. Isocitrate dehydrogenase (IDH) mutant
Majory of diffuse and anaplastic astrocytoma are IDH- mutant
31
Imaging pattern of diffuse and anaplastic astrocytoma (4)
1. Expansile parenchymal lesion
2. Hypodense on CT
3. Hyperintense on T2W
4. Without significant enhancement (intact blood-brain barrier)
32
It may not be possible to distinguish diffuse from anaplastic astrocytoma before biopsy.
What are the possible clues to include the latter?
1. Older age (>40 years old)
2. Imaging markers:
- increased cellularity (decreased diffusion)
- mitotic activity (increased choline)
- tumor vascularity (increased perfusion)
33
This is a Grade IV or malignant astrocytoma and is overall the most common primary intra-axial tumor of the CNS.
Glioblastoma multiforme
It accounts for over hald of gliomas (55%)
34
Vast majority of glioblastoma are:
a. IDH-mutant
b. IDH-wildtype
b. IDH-wildtype
(90%), also known as primary glioblastomas
IDH-mutant (<10%) - also known as secondary glioblastomas - younger adults - less aggressive
35
Imaging pattern of glioblastoma (3)
1. Heterogenously enhancing parenchymal mass with surrounding vasogenic edema.
2. May include calcification or hemorrhage
3. Can present as a single enhancing mass, multifocal enhancing masses, or a combination of both enhancing and nonenhancing tumor
36
Differential diagnosis for ring enhancing lesions (7)
1. Metastasis
2. Abscess
3. Glioma (especially glioblastoma)
4. Infarct (subacute or healing phase)
5. Contusion/ hematoma (subacute)
6. Demyelinating disease
7. Radiation necrosis
(MAGIC DR)
37
Diffuse or infiltrative glioma (commonly glioblastoma) crosses the corpus callosum to involve both cerebral hemispheres
Butterfly glioma
38
In adults - this refers to either a diffuse infiltrative glioma, similar to supratentorial diffuse gliomas but in a less common location, or focal tectal glioma, which is a low-grade tumor in the midbrain that causes obstructive hydrocephalus
Brainstem glioma
39
In young children - this refers to a diffuse infiltrative glioma with highly aggressive behavior, despite absent or minimal enhancement.
Brainstem glioma or diffuse intrinsic pontine glioma
40
This describes widespread infiltrative growth of a diffuse glioma, more commonly astrocytoma than oligodendroglioma, to involve at least three lobes of the brain.
Gliomatosis cereberi
41
Less common and account for only 6% of all gliomas.
Demonstrate diffuse growth pattern, just like their astrocytic counterparts, with neoplastic cells infiltrating beyong the macroscopic margins of the tumor.
Oligodendrogliomas
42
Imaging pattern of oligodendroglioma (9)
1. Expansile infiltrative parenchymal elsions
2. Hypodense on CT
3. Hyperintense on T2
4. Most commonly located in the frontal lobes
5. Extend peripherally to involve cortex
7. More likely to exhibit calcification on CT
8. Poorly defined margin - heterogeneous signal on MRI
9. Vascular - Variable enhancement
43
It may not be possible to distinguish oligodendroglioma from anaplastic oligodendroglioma.
What possible clues to include the latter?
1. Older age (>40 years old)
2. Imaging markers:
- increased cellularity (decreased diffusion)
- mitotic activity (increased choline)
- tumor vascularity (increased perfusion)
44
These arise from the ependymal cells lining the ventricular system and the central canal of the spinal cord, therefore often present as a fourth ventricular mass in children, less commonly as an intramedullary mass in adults.
Ependymomas
45
Imaging pattern of ependymoma (6)
1. Heterogeneous enhancing mass within the fourth ventricle in a child (most common)
2. Capable of paraventricular or transependymal invasion into the brain parenchyma
3. Heterogenous on CT
4. Intratumoral calcification
5. Cystic change
6. Hemorrhage
46
Less common sites of ependymoma
1. Cerebellopontine angles
2. Cerebral hemispheres
3. Lateral-third ventricles
47
Immediately underneath the ependymal lining of the ventricular system lies a thin subependyma glial plate. What tumor arise from this region?
Subependymoma
48
Most common locations of subependymoma (3)
1. Inferior fourth ventricle
2. lateral-third ventricles
3. spinal cord
49
Difference of subependymoma from ependymoma
1. Older adults (>40 years old)
| 2. Hypovascular - show less enhancement on post contrast imaging
50
Choroid plexus tumors occur on what age group?
Children (<20 years old)
51
Spectrum of choroid plexus tumor (3)
1. Choroid plexus papilloma
2. Atypical choroid plexus papilloma
3. Choroid plexus carcinoma
52
Imaging pattern of choroid plexus tumor (2)
1. Intensely enhancing masses with lobulated margins
| 2. Usually centered at the atrium or trigone of the lateral ventricle (arising from the choriod plexus glomus)
53
These tumors are characterized by varying degrees of neuronal differentiation (neurocytes and ganglion cells), often with glial component too.
Neuronal and mixed neuronal-glial tumors.
- Generally present in children or young adults (age <40 years old)
- 1% of all primary CNS tumor
54
This is a benign mixed neuroal-glial tumor with an excellent prognosis, associated with medically refrarctory partial complex seizures in children or yound adults.
Dysembryoplastic Neuroepithelial Tumor (DNET)
55
Typically imaging pattern of DNET
Nonenhancing multycystic (bubbly) mass at the cerebral cortex in a young patient, usually the temporal lobe
56
Pure neuronal tumor composed of neoplastic ganglion cells
Gangliocytoma
57
A mixed glioneuronal tumor with neoplastic glial cells as well.
Ganglioglioma
58
Imaging pattern of gangliocytoma and ganglioglioma
Partially enhancing mass at the cerebral cortex in a young patient
- Most common neoplastic etiology for temporal lobe epilepsy
59
Also known as Lhermitte-Duclos Disease
Dysplastic cerebellar gangliocytoma
60
Classic imaging pattern of dysplastic cerebellar gangliocytoma
Nonenhancing mass that expands the cerebellar folia and causes "striated cerebellum" appearance on MRI.
61
Dysplastic cerebellar gangliocytoma is frequently associated with what syndrome.
Cowden syndrome
- an autosomal dominant phakomatosis with multiple hamartomas and mutations in the PTEN tumor suppressor gene
62
Tumors that present as a heterogeneous mixed cystic-solid mass (cyst and nodule appearance) involving the cerebral cortex.
It may cause desmoplastic reaction with thickening and enhancement of the overlying meninges, analogous to PXA.
Desmoplastic infantile astrocytoma and ganglioma
63
Glial cells form a pseudopapillary arrangement with interpapillary neuronal cells.
It presents as a cerebral mixed cystic-solid mass, with predilection for the temporal lobe, similar to ganglioglioma.
Papillary glioneuronal tumor (PGNT)
64
The glial component resembles a pilocytic astrocytoma, while the neuronal component forms neurocystic rosettes and perivascular pseudorosettes.
It also presents as a mixed cystic-solid mass, but is most commonly located in the midline, around the fourth ventricle, or the cerebral aqueduct.
Rosette-Forming glioneuronal tumor
65
In contrast with other neuronal tumors, which are parenchymal and often cortical in location, this is a ventricular tumor with an unclear cell of origin.
Central neurocytoma
66
Imaging pattern of central neurocytoma
Prensent in young adults (20 to 40 years old)
As an enhancing mass arising from the septum pellucidum or lateral ventricular wall, near the foramen of Monro.
T2 - heterogeneous apperance (bubbly)
67
These are highly malignant tumors of neuroepithelial origin, which are too poorly differentiated to be cathergorized as glial or neuronal tumors.
Embryonal tumors
68
It is the most common CNS embryonal tumor, as well as the second most common pediatric CNS tumor (after PA).
Medulloblastoma
69
Subtypes of medulloblastoma (4)
1. Classic
2. Desmoplastic/nodular
3. Medulloblastoma with extensive nodularity
4. Large cell/anaplastic
70
Imaging pattern of medulloblastoma
Most classic appearance:
| Hyperdense mass at the cerebellar vermis in a young child
71
Pediatric posterior fossa tumors (4)
1. Brainstem Glioma
2. Pilocytic Astrocytoma
3. Medulloblastoma
4. Ependymoma
("GAME")
72
Most common primary intra-axial posterior fossa mass of adulthood.
Hemangioblastoma
| 40 to 60 years old
73
Imaging pattern of hemangioblastoma
Circumscribed enhancing tumors that can secrete fluid and produce internal or adjacent cysts.
74
Primary differential diagnosis of hemangioblastoma
Hypervascular metastasis (renal cell carcinoma)
75
Percentage of hemagioblastoma arising outside the posterior fossa
Fewer than 10%
Often in the setting of VHL, and also present as pial-based enhancing nodules, with or without cysts.
76
Most common non-Hodgkin lymphoma of adults and can arise in virtually any compartment of the body, including the brain parenchyma.
Diffuse large B-cell lymphoma
| Primary CNS Lymphoma or PCNSL
77
Clinical presentation of PCNSL
Older adults (>40 years old) with altered mental status or focal neurologic deficits.
78
Imaging pattern of PCNSL
1. Homogeneously enhancing mass that abuts the CSF space and wraps around the ventricles or sulci
2. With homogeneous hyperdensity on CT
3. Corresponding hypointensity on T2/ADC
4. Can infiltrate the corpus callosum
79
Classic imaging patterns of PCNSL may not apply to immunocompromised patients.
Why?
AIDS-related or EBV-positive PCNSL tends to present with multifocal heterogeneous lesions and variable or ring-like enhancement.
80
50% of brain metases are secondary to what primary cancer?
Lung cancer
81
Common location of metastases in the intracranial or intradural compartment
Parenchymal (usually supratentorial)
than intraventricular, leptopmeningeal, or pachymeningeal metastases.
82
Imaging pattern of metastatic tumor
Classic appearance:
One or multiple enhancing masses, with circumscribed margins, located peripherally near the gray-white matter junction, and surrounded by marked vasogenic edema.
83
It is also known as:
- CSF/subarachnoid dissemination of tumor
- leptomeningeal carcinomatosis
- carcinomatous meningitis
- neoplastic meningitis
- "drop" metastases when originating from a primary tumor
Leptomeningeal metastases
84
Imaging pattern of leptomeningeal metastases
May appear as thin or nodular enhancement in the subarachnoid spaces, often accompanied by loss of normal CSF nulling on T2 FLAIR images, sometimes complicated by communicating hydrocephalus.
85
What are other ways to increase sensitivity for leptomeningeal disease? (2)
1. Delayed postgadolium images
| 2. Postgadolinium T2 FLAIR images
86
Benign extra-axial neoplasms which arise from the vestibular nerve (CN8) - in vast majority of cases.
Schwannoma
- Less commonly, may arise from the other cranial nerves (CN5), and rarely, may arise within the brain parenchyma, possibly originating from peripheral nerves that innervate vessel walls (nervi vasorum).
87
Imaging pattern of schwannoma
Heterogeneous signal intesity, especially when large
Generally described as enhancing T2 hyperintense masses along a peripheral nerve
88
It is characterized by multiple schwannomas (and meningiomas)
- NOT neurofibromas
Neurofibromatosis type 2
89
Bilateral vestibular schwannoma is diagnostic of what disease?
Neurofibromatosis type 2
90
Other peripheral nerve sheath tumor (3)
1. Neurofibroma
2. Perioneurioma
3. Malignant peripheral nerve sheath tumor
91
Most common extra-axial tumors
AND
Most common primary CNS tumor (36%)
Meningioma
92
These arise from arachnoid cap cells in the arachnoid mater, which abuts the dura mater on the inside of the skull.
Meningioma
93
Half of the cases of meningioma present as dural-based masses along what location?
Cerebral convexity
or
falx cerebri (parasagittal)
94
Imaging pattern of meningioma
1. Classic but nonspecific appearance:
A.) Enhancing dural-based mass which may be accompanied by
B.) adjacent dural thickening (dural tail) and
C.) osseous changes (hyperostosis)
2. Avidly enhancing
3. Angiography = radial arrangement of the vessels with an early dense tumor blush that persist well into the venous phase (mother-in-law sign)
95
Cerebellopontine angle masses (4)
1. Arachnoid cyst
2. Meningioma
3. Epidermoid cyst
4. "Neuroma" (schwannoma)
AMEN OR SAME
96
Previously known as angioblastic meningioma.
It arises from modified pericapillary smooth muscle cells (pericytes of Zimmerman).
Hemangiopericytoma
-peak incidence of 30 to 50 years
97
Imaging finding of hemangiopericytoma
1. Similar to meningioma
2. Narrow base instead of broad base attachment
3. Typically multilobulated rather than hemispheric
4. Bone destruction instead of hyperostosis
5. Flow voids
6. MRS shows elevated myoinisitol
98
Site of Origin: Ependymal lining
Age: <20
Enhancement: Strong
What ventricular tumor?
Ependymoma
| Table 5.14
99
Site of Origin: Septum pellucidum
Age: 20 - 40
Enhancement: Strong
What ventricular tumor?
Central neurocytoma
| Table 5.14
100
Site of Origin: Subependymal plate
Age: > 40
Enhancement: Weak
What ventricular tumor?
Subependymoma
| Table 5.14
101
Site of Origin: Choroid plexus epithelium
Age: < 20
Enhancement: Strong
What ventricular tumor?
Choroid plexus tumor
| Table 5.14
102
Site of Origin: Choroid plexus stroma
Age: > 40
Enhancement: Strong
What ventricular tumor?
Meningioma
or
Metastasis
(Table 5.14)
103
Image finding of meningeal melanocyte and melanoma
1. Nonspecific imaging pattern
2. Intradural enhancing mass or masses
3. Intrinsic T1 hyperintensity
104
Classifications of pineal parenchymal tumors (3)
1. ) Pineocytoma - Grade I
2. ) Pineal parenchymal tumor of intermediate differentiation
3. ) Pineoblastoma
105
Most common type of neoplasm in the pineal region.
Germ cell tumor (60%)
106
Subcategories of germ cell tumors (2)
1. ) Germinoma (aka dysgerminoma or seminoma)
| 2. Nongerminomatous or nonseminomatous GCT
107
Difference between germ cell tumor or pineal parenchyma tumor.
Germ cell tumors tend to wrap around or engulf normal pineal calcifications
Pineal parenchymal tumors tend to displace or explode them.
108
Nongerminomatous germ cell tumors (5)
1. Embryonal carcinoma
2. Yolk sac tumor (also known as endodermal sinus tumor)
3. Choriocarcinoma
4. Teratoma
5. Mixed germ cell tumors
109
Heterogeneous enhancing mass with internal fat density or signal should prompt what disease?
Teratoma
110
Heterogeneous midline mass in a newborn should prompt consideration of what diease?
Congenital teratoma
- These tumors are thought to arise in utero (may present at any age)
111
Tumor arising from the subcommissural organ - a small ependymal gland located at the posterior margin of the third ventricle, just below the posterior commissure.
Papillary tumor of the pineal region (PTPR)
- Enhancing mass in adults. Can be hard to differentiate from other pineal regions tumors.
112
Tumor arising from the adenohypophysis.
One of the three most common primary neoplasms.
Adenomas
Most common primary:
1. meningiomas - 36%
2. adenomas - 16%
3. glioblastoma - 15%
113
What are the size of micro- and macroadenoma.
Microadenoma - < 1 cm
| Macroadenoma - > 1 cm
114
Most common adenoma of the pituitary gland which can cause amenorrhea/ galactorrhea in women or decreased libido in men.
Prolatinoma
- GH secreting adenomas are second most common
115
Pituitary mass that may cause local mass effect:
- visual loss (compression of optic nerves, chiasm, or tract superiorly)
- hypopituitarism or hyperprolactinemia (compression of pituitary gland or stalk, respectively)
- Lateral invasion of the cavernous sinus
Macroadenoma
116
Imaging pattern of pituitary adenoma
1. Relatively hypoenhancing lesion (lack of blood-brain barrier)
2. Hyperdence in CT
3. Hypointense on T2
4. Can be heterogenous signal related to cyst, infarcts, or hemorrhages.
117
An acute syndrome - when pituitary macroadenoma suddenly enlarges due to hemorrhage
Pituitary apoplexy
118
Tumor that arise from squamous epithelial remnants of the craniopharyngeal duct, also known as Rathke pouch.
Craniopharyngioma
119
Most common nonneuroepithelial CNS tumor of childhood.
Adamantinomatous craniopharyngioma
120
90% rule of adamatinomatous craniopharyngioma (3)
1. ) 90% show cystic change
2. ) 90% show calcification
3. ) 90% show solid or nodular enhancement
121
A craniopharyngioma that is less common and tends to present in older adults as a solid enhancing mass
Papillary craniopharyngioma
122
This is a nonneoplastic cyst that result from a persistent cleft in Rathke pouch that fails to involute.
Rathke cleft cyst
123
Rathke cleft cyst can have solid or nodular enhancement.
True or false.
False.
Unlike the craniopharyngioma, a Rathke cleft cyst is developmental not neoplastic and has no solid enhancement
124
Suprasellar masses (7)
1. Sarcoidosis
2. Adenoma, Aneurysm
3. Teratoma/germinoma, Tuberculosis
4. Craniopharyngioma, Rathke Cleft Cyst
5. Hypothalamic glioma, Hamatroma, Histiocytosis
6. Meningioma, Metastsis
7. Optic pathway glioma
125
These are thin-walled meningothelial cyst that are located in the subarachnoid space and are thought to result from a congenital duplication or splitting of the embryonic arachnoid during development.
Arachnoid cysts
126
Rarely, secondary or acquired arachnoid cyst can also develop as chronic sequelae of prior inflammation (meningitis, hemorrhage).
True or false.
True
127
Image finding of arachnoid cyst
It follows CSF density or signal on CT and MRI.
50% are seen in middle cranial fossa
-other sites: cerebral convexities, basal cisterns, and posterior fossa.
128
This is a large retrocerebellar CSF space
Mega cisterna magna
129
During closure of the embryonic neural tube, which is formed from neuroectoderm, the abnormal inclusion of surface or external ectoderm can produce cysts with lining that resemble normal skin epithelium.
Epidermoid and dermoid cysts
130
Imaging pattern of epidermoid cyst
1. More lateral (CPA)
2. lobulated cyst
3. CSF density on CT
4. CSF signal on T1 and T2W images
5. Hyperintense on DWI (unlike arachnoid cyst)
6. Rare - hyperdense on CT and hyperintense on MR = white epidermoid
131
Imaging pattern of dermoid cyst
1. Fat density on CT and MRI
2. No demonstrable solid or nodular enhancment
3. May rupture into the subarachnoid space - producing aseptic or chemical meningitis, with multipe fatty-type droplets (sebum) on imaging
132
These are endodermal inclusion cysts, whose lining resembles bronchial or respiratory epithelium, hence filled with mucin and are highly proteinaceous.
Colloid cysts
133
Location of colloid cyst
At the anterosuperior roof of the third ventricle near the foramen of Monro, where the can cause acute hydrocephalus and sudden death.
134
Clinical presentation of colloid cyst
1. Paroxysmal headaches
2. Neurologic deficits
(exacerbated by tilting the head forward - Brun phenomenon - due to ball-valve action of the cyst.
135
Image pattern of colloid cyst (2)
1. Round hyperdence lesion at the anterior third ventricle near the foramen of Monro on noncontrast CT
2. Variable signal intensity on T1/T2
136
These are nonneoplastic masses of true adipose tissue that result from maldifferentiation of the embryonic meninx primitiva into fat rather than normal subarachnoid space.
Intracranial lipoma
137
Most common locations of intracranial lipoma (3)
1. Interhemispheric fissure
(possible associated with callosal dysgenesis)
2. Suprasellar cistern
3. Quadrigeminal cistern
138
Presentaion of hamartoma of the tuber cinereum
1. Gelastic seizure (laughing fits.)
| 2. Precocious puberty
