atypical and infrequent sellar and suprasellar lesions: what the neuroradiologist needs to know!...

Atypical and Infrequent Sellar and Suprasellar Lesions: What the

Neuroradiologist Needs to Know!

Rafael Glikstein MD

Bardia Moosavi MD

Jorge Davila MD

Mauricio Castillo MD

Carlos Torres MD

No Disclosures.

PurposeTo present atypical and infrequent pathologies that can occur in the sellar/suprasellar location, with emphasis on MR imaging findings.

ApproachIn this pictorial review, we present several cases of atypical and infrequent diseases affecting the sellar/suprasellar region and describe the relevant imaging findings.

Case 1a

Craniopharyngioma

• Ectodermal derived epithelial tumor (Rathke pouch remnant)

• Contain cholesterol, keratin, protein, blood products, and necrotic debris

• 2 Types – Adamantinomatous (90%)– Papillary (10%)

• Bimodal age distribution − Peak in children 5-10 years − Peak in adults 40-50 years

• Slow growth

CT• Can be very large (>5cm) • Adamantinomatous: 90% cystic, 90%

calcify, 90% enhance• Papillary: solid>cystic

MRI• Variable T1 signal• Typically hyperintense on T2/FLAIR

Case 2

2008

2013

Intracystic Mobile Nodule of Rathke’s Cleft Cyst

• Ectodermal remnants of the craniopharyngeal duct • 60% suprasellar • Intracystic nodule present in 40-75% of cases, which can mimic

craniopharyngioma

CT• Well-defined round or oval mass• Majority are hypodense• Calcification is rare

MRI• 50% hypointense, 50%

hyperintense on T1W• Hyperintense on T2W/FLAIR• May have claw-like peripheral

enhancement

Case 3

Cyst of Liliequist Membrane

• Liliequist membrane is an arachnoid membrane from the dorsum sellae to the anterior edge of the mamillary body. It has a vertical mesencephalic segment as well.

• This membrane has neurosurgical importance especially in endoscopic and microinvasive surgery.

Imaging

• This membrane is not routinely visualized in imaging studies as it is very thin.

• However, Liliequist membrane can be visualized with heavily T2-weighted 3D constructive interference steady state (CISS) sequence.

• Cyst arising from Liliequist membrane can mimic Rathke cleft cyst and craniopharyngioma

Modified by Fushimi et al. Radiology 2003

Case 4

Chordoid Glioma

• Arise from the anterior 3rd ventricle • Rare tumor with both glial and chordoid feature (<1% of all gliomas)• Typically occurs in middle aged adults; 2:1 F:M• Visual field deficit is most common abnormality on exam

CT• Hyperdense solid mass (28%

may show central cystic change)

• Uniform enhancement• Calcifications present in 10-

15%

MRI• Mass separate from the pituitary

and infundibulum• Iso-intense to brain on T1- and

T2W• Uniform enhancement• These MRI characteristics may

vary depending on the presence and degree of necrosis within the tumor

Case 5

Clivus Chordoma

• Notochord remnant• 1% of intracranial tumors• May extend to nasopharynx • Visual symptoms, cranial nerve palsy

CT• Well-circumscribed hyperdense

mass• Variable enhancement• Intratumoral dystrophic

calcifications

MRI• Intermediate to low signal on

T1W• Typically hyperintense on T2W• Moderate enhancement

Case 5

Pituitary Gangliocytoma

• Slow growing neuroepithelial tumor• Most common in the temporal lobe (>75%) but can occur

anywhere • 50% enhance

CT• Variable density • Calcifications common (30-50%)

MR• Hypo-isointense to

grey matter • No surrounding

edema • Variable

enhancement, usually moderate

Case 6

CNS Lymphoma

• Primarily composed of B lymphocytes • Poor prognosis

CT• Iso-hyperdense • Hemorrhage and necrosis

may occur in immunocompromised patients

MR• Homogeneously iso-

hypointense to cortex on T1- and T2W − May be heterogeneous

from hemorrhage or necrosis

• Mild surrounding edema• Shows restricted diffusion• Homogenous enhancement

Case 7

Pituitary Apoplexy

• Hemorrhage or infarction of the pituitary gland/adenoma • Acute severe headache, visual loss• Can be life threatening due to acute adrenal insufficiency

CT• Sellar/suprasellar mass

with patchy or confluent hyperdensity

MR• Enlarged pituitary,

hyperintense on T1- and T2W in the subacute phase

• “Blooming on GRE”• May show rim

enhancement

Case 8

Lymphocytic Hypophysitis

• Idiopathic inflammation of the pituitary • 8-9:1 F:M• Delayed diagnosis and treatment may lead to death from

panhypopituitarism • Steroids and replacement therapy for deficient hormones

Imaging• Round pituitary gland and thick stalk (>2 mm and

nontapering)• 75% show loss of posterior pituitary “bright spot” on

T1W • Iso-hypointense on T2W• Uniform enhancement

Case 9

Sarcoidosis

• Granulomatous multisystem disorder– CNS involvement in 15%

• Unknown etiology • May cause hypothalamo-pituitary dysfunction

– Single hormone insufficiency or panhypopituitarism

Imaging• Iso-hypointense on T1- and T2W• Sellar disease may appear cystic• Variable enhancement

• 5-10% seen as hypothalamic and infundibular thickening and enhancement

Case 10

50 y/o patient being treated for metastatic melanoma.

Ipilimumab-Induced Hypophysitis

• Autoimmune secondary hypophysitis • Ipilimumab enhances immune-mediated destruction of metastatic

melanoma (FDA approved in March 2011)– Blocks CTLA-4 protein in the surface T cells – Proliferation and increase in T lymphocytes – Improves immune system for destruction of cancer cells

• Life-threatening complication related to hypocortisolism• Tx: High dose steroids and hormone replacement

Imaging• Pituitary enlargement ± masses• Thickening of the pituitary stalk

Ipilimumab-Induced Hypophysitis

Before medication

During/after

Follow up

Case 11

Cavernous Malformation (Cavernoma)

• Vascular malformation in the region of the third ventricle and tuber cinereum of the hypothalamus

• Patients may present with precocious puberty and intractable epilepsy

CT• Normal in 30-50%• Well-defined hyperdense lesion • 40-60% calcify

MR• “popcorn” like appearance • Mixed hyper-hypointense

blood-containing locules on T1W

• Mixed signal core and hypointense hemosiderin rim on T2W

• Prominent susceptibility effect on GRE

• Minimal or no enhancement

Case 12

Hamartoma of the Tuber Cinereum

• Non neoplastic heterotopic grey matter • Located between the mammillary bodies and infundibulum • May present with seizures, precocious puberty

CT• Homogenous, isodense

suprasellar mass• Calcification is

uncommon

MR• Hypo-isointense to grey

matter on T1W• Slightly hyperintense on

T2W• No enhancement

Case 13

Normal

Case 13

Hypermanganesemia

• More common in setting of chronic liver failure but may also result from occupational exposure

• Mn neurotoxicity is attributed to impaired dopaminergic, glutamatergic and GABAergic transmission, mitochondrial dysfunction, oxidative stress and neuroinflammation

• Preferential accumulation in the dopaminergic cells of the basal ganglia, particularly the globus pallidus, causing extrapyrramidal motor dysfunction

Imaging• High T1W signal in the adenohypophysis, hypothalamus and mesencephalon

due to accumulation of manganese • No contrast enhancement

Summary

Diverse pathologic processes that infrequently affect the sellar/suprasellar structures have characteristic features on MR, which help in narrowing the differential diagnosis.

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