Radiology Assistant: Sellar And Parasellar Tumors

Front 1

What is the seven step approach to determining sellar pathology

Back 1

-First identify the pituitary gland and sella turcica.
-Then determine the epicenter of the lesion and whether it is in the sella or above, below or lateral to the sella.
-If it is in the sella, determine whether or not the sella is enlarged.
-Once the location of the mass is clear, analyze the signal intensity patterns: is the lesion cystic or solid?
- Determine if it contain any abnormal vessels?
-Determine if there is any calcifications?

Front 2

So basically you want to find determine the epicenter of the lesion, if it is enlarging the sella, and if it has fat, cystic changes, a solid component, calcificaitons and any vessels

Back 2

yes

Front 3

What bony structure does the pituitary gland lie within

Back 3

the sella turcica

Front 4

Do females tend to have a convex superior margin of the sella turcica

Back 4

yes, it appears to be bulging out and this is normal. Males will be concave

Front 5

What are the 3 most common abnormalities that arise from the pituitary gland

Back 5

pituitary adenoma, Rathke's cleft cyst and craniopharyngioma

Front 6

What are the common pathology that arise from the pituitary stalk

Back 6

rathkes cleft cyst
craniopharyngioma
germinoma
eosinophilic granuloma
mets

Front 7

Can a rathkes cleft cyst and a craniopharyngioma both arise from the stalk or the pituitary gland its self

Back 7

yes

Front 8

What demographic tends to get germinoma and eosinophilic granulomas of the pituitary stalk

Back 8

children

Front 9

Can mets and lymphoma also be found in the pituitary stalk

Back 9

yes

Front 10

Is the optic chiasm technically in the suprasellar cistern

Back 10

yes

Front 11

What is the MC tumor to arise from the optic chiasm

Back 11

gliomas

Front 12

What demylinating disease commonly affects the optic chiasm

Back 12

MS

Front 13

How can you tell if the optic chiasm is effected by MS

Back 13

it will be swollen

Front 14

What is just above the optic chiasm

Back 14

the hypothalamus

Front 15

What ventricle does the hypothalamus help make up the walls of

Back 15

3rd ventricle. Anatomically the hypothalamus forms the lateral walls and floor of the third ventricle.

Front 16

What pathology may occur in the hypothalamus of children

Back 16

hamartomas, germinomas and eosinophilic granuloma.

Front 17

What does the supracavernous segement of the ICA bifurcate into

Back 17

anterior cerebral artery, which passes cranially to the optic chiasm, and the middle cerebral artery, which runs laterally.

Front 18

What pathology may involve the ICA

Back 18

aneurysm

Front 19

What nerves run through the cavernous sinus

Back 19

nerve III (oculomotorius), IV (trochlearis), V1 and V2 (trigeminus).
The sixth cranial nerve (abducens) runs more medially and is located caudal to the carotid artery.

Front 20

What are some examples of common pathology that

Back 20

schwannoma
thrombosis
C-C fistula

Front 21

Do meninges cover the cavernous sinus

Back 21

Front 22

Back 22

Front 23

What 2 pathology may arise from the meninges

Back 23

meningioma
mets
meningitis

Front 24

Where is the sphenoid in relation to the the pituitary gland

Back 24

bellow the sella turcica

Front 25

What are the 2 bony boundaries of the pituitar

Back 25

the area it lies in is the sella turcica
Front-tuberculum sella
Back-Dorsum sella

Front 26

What pathology may arise from the sphenoid

Back 26

SCC and adenoid cystic carcinoma
chordoma, chondrosarcoma, and osteosarcoma from the clivus
bacterial and infections can also occur here.

Front 27

What is the size criteria for a pituitary microadenoma

Back 27

less than 10mm

Front 28

What is the ddx of a pituitary microadenoma

Back 28

a rathkes cleft cyst

Front 29

What is the treatment if a pt has excessive hormone production from a suspected pituitary adenoma

Back 29

an MR without contrast. It doesnt matter if it is negative the only thing that the ordering physician is concerned about is if there is a large mass. Pt will be treated symptomacally no matter if it is negative or if there is a small microadenoma

Front 30

What if the pt fails conservative therapy then is contrast necessary

Back 30

yes, you want to see the small lesion as accurately as possible

Front 31

What percent of pituitary microadenomas are detected by non-contrasst MR

Back 31

70%

Front 32

What percent of microadenomas are detected with MR with gad

Back 32

85%

Front 33

What is the size definition of a macroadenoma

Back 33

>10mm

Front 34

Describe the appearance of a macroadenoma

Back 34

They tend to be soft, solid lesions, often with areas of necrosis or hemorrhage as they get bigge

Front 35

Why do macroadenomas get the snowman appearance

Back 35

Because they are soft tumors, they usually indent at the diaphragma sellae, giving them a 'snowman' configuration.

Front 36

What are 2 ways to differentiate a meningioma from a macroadenoma

Back 36

a meningioma will not compress in at the diphragma sella and it will not expand the sella turcica

Front 37

Does a pituitary macroadenoma expand the sella turcica

Back 37

yes

Front 38

What is the covering of the sella turcica

Back 38

diphragma sella

Front 39

Do meningiomas typically have uniform enhancement

Back 39

yes

Front 40

How is the sella turcica violated for surgery of a macroadenoma

Back 40

through the floor of the sella turcica and the macroadenoma is taken out via the sphenoid sinus

Front 41

What is the most common tumor of the skull base

Back 41

pituitary adenoma

Front 42

Pathologically what does a Rathkes cleft cyst look like

Back 42

The cyst is fluid-filled and has very thin walls with a thickness of only one or two cell layers

Front 43

Can a rathkes cleft cyst occur in or above the sella turcica

Back 43

yes

Front 44

What is the main ddx of a suprasellar cystic structure

Back 44

craniopharyngioma
Rathkes cleft cyst

Front 45

What is a similarity of a ratkes cleft cyst an a pituitary adenoma

Back 45

they both will not enhance with contrast

Front 46

Since all extracellular masses enhance, what is the ddx of a non-enhancing extracellar mass

Back 46

Rapid arterial flow (eg. large blood vessel).
No cellular tissue (eg. cyst).
No blood supply (eg. infarcted mass).
pituitary adenoma

Front 47

Is a major difference between a rathkes cleft cyst and a craniopharyngioma

Back 47

Technically these are benign tumors, but unlike Rathke's cleft cysts, they have thick walls and are locally invasive

Front 48

What is the common appearance of a craniopharyngioma

Back 48

A large intrasellar and suprasellar mass with cystic and enhancing components as well as calcifications.

Front 49

Can a cranipharyngioma be both intrasellar and extrasellar

Back 49

yes

Front 50

What is the main ddx of a craniopharyngioma

Back 50

teratoma

Front 51

What percent of meningiomas occur at the skull base

Back 51

The most common intracranial tumor in adults is the meningioma with 20% of occurring at the skull base

Front 52

Are meningiomas generally solid tumors that can have occasional peripheral cystic change

Back 52

yes

Front 53

What suprasellar lesion must always be ruled out first

Back 53

aneurysm

Front 54

What tends to happen to pituitary adenomas as they enlarge in size

Back 54

When pituitary macroadenomas get this size they usually have areas of hemorrhage or necrosis - in mengiomas this is less often the case.

Front 55

What 3 lesions can be partially in the sella turcica and partially suprasellar

Back 55

aneurysm
menigioma
adenoma

Front 56

What are 3 things that are black on MRI

Back 56

air
bone
rapid blood flow

Front 57

Can a mass compressing upon the pituitary cause increased hormone release

Back 57

yes, even an aneurysm

Front 58

What is the stalk section effect

Back 58

The pituitary stalk connects the hypothalamus to the pituitary gland and hormones produced in the hypothalamus are transported to the anterior lobe of the pituitary gland via portal veins running along the stalk.
Most of these hormones stimulate the production of other hormones in the pituitary gland (such as TRH, GnRH, GHRH and CRH), but the release of dopamine inhibits the production of prolactin by the anterior lobe of the pituitary.
Therefore when the stalk is compressed by a mass or is transected, the level of prolactin rises while all the other hormone levels decrease.
This is known as the 'Stalk Section Effect'. It is the reason why masses other than adenomas can cause hyperprolactinemia.

Front 59

What are suprasellar hamartomas

Back 59

Hamartomas masses of dysplastic tissue found almost exclusively in young children.

Front 60

What demographic typically gets suprasella hamartomas

Back 60

children

Front 61

Do hamartomas enhance

Back 61

no

Front 62

Where do suprasellar hamartoma typically arise

Back 62

they hang down from the floor of the third ventricle. The best images to see hamartomas on are enhanced sagittal T1-weighted MR images.
Here you can see the non-enhancing hamartoma attached to the tuber cinereum between the pituitary stalk and mamillary body.

Front 63

Why is it important to know what the tuber cinereum is

Back 63

it is the portion of the between the mamillary body and the stalk where hamartomas arises.

Front 64

If you see a non-enhancing mass attached to the tuber cinereum in a child what is the ddx

Back 64

there is non ddx. Its a hamartoma

Front 65

What hereditary disease predisposes patients to optic gliomas

Back 65

NF1

Front 66

Do optic gliomas typically enhance

Back 66

yes, but not all of them

Front 67

Do 25% of optic gliomas not enhance

Back 67

yes, only 75% show the typical enhancement pattern

Front 68

What is a good way to determine if a lesion is an optic glioma

Back 68

look at the optic nerve and if there is enlargement of the optic nerve as it moves into the orbit it is likely an optic glioma

Front 69

What demographic will typically get germinomas

Back 69

children and adolescents

Front 70

Do germinomas typically enhance

Back 70

yes

Front 71

Where do germinomas typcially occur

Back 71

these are midline by the hypothalamus but also will occur in the pineal gland area

Front 72

Can a germinoma show restricted diffusion

Back 72

yes

Front 73

Do germinomas typically crawl along the floor of the 3rd ventricle

Back 73

yes

Front 74

What are 3 lesions that will typically occur in the clivus

Back 74

chordoma
chondrosarcoma
mets

Front 75

What is a good general rule of thumb for a chordoma Vs a chondrosarcoma

Back 75

chordomas tend to occur midline
chondrosarcomas will tend to occur off midline

Front 76

Can a chordoma and chondrosarcoma both have calcifications

Back 76

yes

Front 77

What is the signal intensity of the clivus normally on T1

Back 77

high signal intensity but if infiltrated by tumor it may be dark.