Neuro -- Sella And Suprasellar Masses

Front 1

1. What does the pneumonic “SATCHMO” stand for?
2. What are the less common parasellar masses?

Back 1

S = Sphenoid sinus tumor, sarcoidosis
A = Aneurysm (lamellated; phase artifact), Adenoma (pituitary)
T = Teratoma
C = Craniopharyngioma
H = Hypothalamic glioma, Hamaratoma of the Tuber Cinereum
M = Meningioma, metastasis
O = Optic glioma

2.
Germinoma (suprasellar) -- usually seen in a child; intense enhancment; may have second lesion in pineal gland region.
Rathke Cleft cyst
Epidermoid/Arachnoid cyst
Chordoma

Front 2

1. What are the imaging findings of craniopharyngioma?
2. What is the age distribution of craniopharyngioma?
3. How does it present clinically?

Back 2

1.
- Extremely HETEROGENEOUS mass composed of intermixed CYSTIC and SOLID components.
- T1 HYPERINTENSITY may be 2/2 proteinaceous cystic component.
- INTRASELLAR with suprasellar extension.
- Majority have CALCIFICATIONS (MC in pediatrics group).
2. Bimodal age distribution:
Adamantinomatous subtype:
- MC pediatric age group (11-14 years old)
- Cystic and solid mass
Papillary (solid) type:
- occurs in the 5th decade.
3.
- Headache from obstructive hydrocephalus
- Visual sx 2/2 compression of optic chiasm.

treatment is surgical but craniopharyngioma tends to adhere to adjacent brain structures and surgery is often incomplete. Local recurrence is common, and radiotherapy is often necessary.

Front 3

1. What is a Rathke pouch cyst?
2. What are its imaging features?
3. What does it mimic on imaging?

Back 3

1.
- Benign epithelium-lined INTRASELLAR cysts with possible suprasellar extension.
- Originates from remnants of the Rathke pouch
2.
- Circumscribed cystic sellar mass, ANTERIOR to the pituitary gland.
- May extend into the suprasellar region.
- Differing attenuation/SI based on contents of cystic component.
- No enhancement
3.
- If simple cyst => difficult to distinguish from arachnoid cyst or epidermoid.
- If complex cyst => may be indistinguishable from a craniopharyngioma or pituitary adenoma.

Front 4

1. Where is the tuber cinereum located?
2. What is a tuber cinereum hamartoma?
3. What are the imaging findings?
4. What symptoms are associated with hamartoma of the tuber cinereum?

Back 4

1.
- Located BETWEEN the INFUNDIBULAR STALK anteriorly and the MAMILLARY BODIES posteriorly.
- Forms the FLOOR of 3RD VENTRICLE which should be smooth. Any nodularity in this region should raise suspicion for a hamartoma in the appropriate clinical setting.
2. Non-neoplastic heterotopia composed of normal neuronal tissue.
3.
- PEDUNCULATED or SESSILE.
- Ranges in size from a few millimeters to 3-4 cm.
- NO ENHANCEMENT (NOTE: if there is enhancement of a hypothalamic lesion, then think hypothalamic glioma)
- Iso- dense/intense to gray matter on CT and T1WI.
- T2WI may show HYPERINTENSITY.
4.
- Gilastic seizures
- Precocius puberty

Front 5

1. Are pituitary microadenomas more common than macroadenomas?
2. What is the size criteria for pituitary adenoma?
3. What is the most common hormonally active pituitary adenoma? What are the clinical features?
4. What are the imaging findings of pituitary microadenoma?
5. What is the etiology of incidentally detected pituitary lesion?

Back 5

1. Microadenomas are 400x more common than macroadenomas.
2.
- Microadenoma is defined as an adenoma < 1 cm in diameter.
- Macroadenoma is a pituitary adenoma > 1 cm in diameter. Macroadenomas grow superiorly through the diaphragma sella. There is an invasive variety of pituitary macroadenoma which demonstrates infiltrative characteristics with invasion of the cavernous sinus, paranasal sinus, clivus/skull base, and brain parenchyma.
3.
- Prolactinoma.
- FEMALES: amenorrhea and galactorrhea
- MALES: lack of libido
4.
- CONTOUR DEFORMITY of the gland.
- SELLAR FLOOR may be DEPRESSED on side of microadenoma.
- Low on T1WI as compared to background pituitary gland. Dynamic study with Gd increases conspicuity -- microadenomas usually appear hypointense compared with normal enhancing pituitary parenchyma. EXCEPT the ACTH secreting microadenomas which enhance more than the pituitary gland.
5. Incidental pituitary lesions are common (6%). The etiology of these lesions include,
- Nonfxning adenoma
- Focal hyperplasia
- Rathke's cleft cyst
- Infarction
- Hemorrhage
Therefore, microadenoma should be dx'ed only in appropriate clinical setting.

Front 6

1. What are the imaging findings of pituitary macroadenoma?
2. What are the complications of pituitary macroadenoma?
3. What can you see with invasive macroadenoma?
4. What are the post-surgical changes for macroadenomas?

Back 6

1.
- Lobulated well defined mass that bulges superiorly through the diaphragm sella into the suprasellar cistern.
- Characteristic figure of 8 appearance with waist at level of the diaphragma sella.
- Enlargement of the sella turcica seen on radiographs
- May encase the carotid artery, however, does not cause narrowing of the carotid artery. Whereas other sellar masses such as meningioma, mets, chordoma leads to narrowing of the ICA.
- Commonly undergo hemorrhage with medical treatment. However, this hemorrhage does not have the same impact as pituitary apoplexy as pts remain asymptomatic from the hemorrhage.
2.
- Bitemporal hemianopsia secondary to mass effect on optic chiasm
- Cranial nerve palsies 2/2 caveronous sinus compression/invasion
- Pituitary apoplexy (sudden infarction - bland or hemorrhagic)
3.
- Invasive macroadenomas may encase the cavernous carotid artery, however, they do not cause arterial narrowing, unlike meningiomas which typically narrow the vessels they surround.
- Invasion of cavernous sinus
- Invasion of clivus
3. Fat packing is generally placed in the sphenoid sinus at the time of surgery. Therefore, fat saturation on post-operative post contrast studies should be done. Over time, the fat will necrose and scar down and may appear similar to residual or recurrent tumor.

Front 7

1. What is the DDX of thickening of the pituitary infundibulum?
2. What clinical symptom is associated with pituitary stalk involvement?

Back 7

- Sarcoidosis
- Langerhans' cell histiocytosis: typically occurs in children, look for associated destructive skull and temporal bone lesions.
- Lymphoma
- Glioma
- TB
- Mets
2. Diabetes insipidus

Front 8

1. What are examples of intrinsic neoplastic pituitary masses?
2, What are examples of inlfammatory pituitary masses?

Back 8

1. Pituitary adenoma, Rathke's cyst, Mets, Choristoma (vascular tumor of the posterior pituitary
2. Abscess (look for sphenoid sinus disease), Others (lymphocytic hypophysitis-usually post pregnancy))

Front 9

Extrinsic sellar masses

Back 9

Neoplastic or cyst:
- Meningioma
- Rathke's cyst: can be within or external to pituitary gland.
- Craniopharyngioma
- Glioma (chiasm-hypothalamus)
- Mets
- Hypothalamic hamartoma

Inflammatory:
- Abscess
- Sarcoidosis

Front 10

Approach to parasellar masses

Back 10

- The initial determination: is the lesion extending from the pituitary gland or separate from it?
- Is the lesion within the cavernous sinus?
- Is the carotid artery narrowed? Meningioma, Mets, Tolosa Hunt (inflammatory process similar to orbital pseudotumor that occurs in the cavernous sinus).

Front 11

Ectopic posterior pituitary

Back 11

- Bright spot of the posterior pituitary gland is ectopic in location.
- Small sella turcica
- Absent/hypoplastic anterior pituitary (therefore, pt presents with hypopituitarism).

Front 12

Cavernous sinus mass/enhancement

Back 12

MENINGIOMA:
- typically present with ocular symptoms
- encases and NARROWS the internal carotid artery.
- dural tail sign, hyperostosis of skull base
SCHWANNOMA:
- most often involves the trigeminal nerve.
- may extend posteriorly into Meckel's cave and CPA.
CAROTID CAVERNOUS FISTULA:
- most are direct and result from trauma or aneurysm rupture.
TOLOSA HUNT SYNDROME:
- idiopathic, inflammatory process (related to orbital pseudotumor)
- iso-, hypo- on T1 and T2 with enhancement following gadolinium.
SARCOIDOSIS
- may be mass-like
- typically presents wiht smooth or nodular enhancment along the cranial nerves along with dural and leptomeningeal enhancement.
PERINEURAL SPREAD OF TUMOR:
- infiltrating sinonasal or head/neck cancers may extend into the cavernous sinus via skull base foramina.

Front 13

Suprasellar mass in a child:

Back 13

- **Craniopharyngioma: MC
- Germ cell tumor: 2nd most common; in a pediatric population the sella/suprasellar region is a more common location than pineal location as in adults)
- Hypothalamic/chiasmatic glioma: 3rd most common.
Less common:
- Pituitary macroadenoma
- Dermoid