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