Transcript Not an Adenoma, Now What?

Not an Adenoma, Now What?:
A review of non-adenomatous sellar
lesions
Sara Koenig, MD
Carlos Bazan, MD
Disclosures
 Sara Koenig – no financial interests to disclose.
 Carlos Bazan – no financial interests to disclose.
Purpose
 The purpose of this exhibit is to review the wide differential of
non-adenomatous lesions of the sella with relevant individual
clinical imaging cases.
 Greater than 90% of sellar lesions are adenomatous.
 However, not all pituitary lesions are adenomas.
Approach/Methods
 A retrospective review of neuroradiology cases at the
University of Texas Health Science Center at San Antonio was
performed to identify cases of non-adenomatous sellar lesions
based on imaging characteristics, some with confirmed
pathologic tissue diagnosis. Additionally, a review of literature
of sellar lesions was performed.
 Lesions were classified into four categories:




Congenital
Neoplastic
Vascular
Infectious
CONGENITAL SELLAR LESIONS
 Empty Sella
 Rathke’s Cleft Cyst
 Sellar Spine
 Cephalocele
 Transected Stalk
 Epidermoid Cyst
 Hypothalamic Hamartoma
 Lipoma
Empty Sella
XR
 Due to protrusion of an arachnoid lined CSFfilled portion of the suprasellar cistern through
wide diaphragma sellae into the bony sella
turcica.
 Filled partially with CSF
 Rarely completely "empty“.
 Pituitary gland is almost never completely absent.
 Case Imaging Findings:
 Skull radiographs demonstrate a ballooned sella
with undercutting anteriorly.
 CT images demonstrate a large sella, hypodense.
CT
CT
Empty Sella (continued)
 MR images demonstrate a sella filled with cerebrospinal fluid
with thin rim of pituitary tissue.
 Dark CSF on T1.
 Bright CSF on T2.
 Dark CSF on T1 + Gd and normal enhancement of remaining
pituitary tissue (arrow).
T1
T2
Gd
Rathke's Cleft Cyst
 Nonenhancing,
noncalcified, intra/suprasellar cyst with
intracystic nodule.
 Completely intrasellar
(40%), suprasellar
extension (60%).
 Density/intensity varies
with cyst content
(serous vs. mucoid).
T1
T1
T2
Gd
Gd
Gd
 Most symptomatic
when at 5-15 mm in
diameter.
 Case Imaging
Findings:
 T1W and post contrast
images demonstrate
“claw sign,” an
enhancing rim of
compressed pituitary
surrounding a
nonenhancing cyst.
 T2W images
demonstrate a
hypointense cystic
lesion.
Sellar Spine
CT
 A sellar spine is an
anatomical variant
characterized by an osseous
spine that arises in the
midline from the dorsum
sellae and protrudes into the
pituitary fossa.
 Case Imaging Findings:
 CT images demonstrate the
osseous spine protruding into the
pituitary fossa (arrows).
 T1W axial image demonstrates
the osseous spine appearing
isointense to the skull and
hyperintense to brain
parenchyma, protruding into the
sella.
T1
CT
Transphenoidal Cephalocele
 Rare 1 in 700,000.
 Assoc with other midline defects:
cleft palate, CC dysgenesis,
hypertelorism.
 Present with craniofacial deformities,
CSF rhinorrhea, meningitis.
 T1 sag and cor images help define
the lesion.
 CT better for defining bone defect
and cisternography shows continuity
with subarachnoid space.
T1
T1
CT
CT Cisternogram
Transected Stalk
 Associated with breech deliveries in children.
 In adults can be acquired by head trauma.
 Typically presents with hormone deficiency in both children and adults.
 Case Imaging findings:
 Small anterior pituitary gland is demonstrated in the sagittal T1W image below.
 Absence or hypoplasia of pituitary stalk, as is shown below on the T1W images.
T1
T1
T1
Epidermoid Cyst
 An epidermoid cyst is a
congenital inclusion of
ectodermal epithelial
elements.
 Case Imaging Findings:
 CT images demonstrate
a sellar hypodense
lesion.
 T1W images
demonstrate an isodense
sellar lesion with post
contrast pituitary rim
enhancement.
 T2W images
demonstrate
heterogenous
hyperintense signal, as
expected with a cyst.
CT
CT
T1
T2
CT
Gd
Hypothalamic Hamartoma
T1
Gd
 Caused by congenital gray
matter heterotopia in region of
tuber cinereum (arrow).
 Also known as a tuber
cinereum hamartoma.
 Can be either sessile or
pedunculated.
 Classically a mass located
between mammillary bodies and
infundibulum.
 Case Imaging Findings:
 Nonenhancing hypothalamic
mass contiguous with tuber
cinereum.
 Isointense to gray matter on
T1/T2.
Gd
T2
T1
T1
Lipoma
 Rare cause of sellar
region lesions.
 Congenital abnormal
rest of fat cells due to
abnormal resorption of
the meninx primitiva.
 Has classic fat MR
signal.
 Case Imaging
Findings:
 T1W image
demonstrates a well
circumscribed rounded
hyperintense
suprasellar lesion.
 T2W image
demonstrates a
hypointense
suprasellar lesion,
consistent with fat.
T2
NEOPLASTIC LESIONS
 Meningioma
 Germ cell tumor – Germinoma
 Craniopharyngioma
 Chiasm Astrocytoma
 Pituicytoma
 Schwannoma
 Lymphoma
 Teratoma
 Metastasis
Meningioma
 Well circumscribed
mass about the sella
with MR
characteristics of a
meningioma.
 Case Imaging
Findings:
 T1W images
demonstrate a mass
isointense to brain
parenchyma.
 T2W images
demonstrate a lesion
nearly isointense to
gray matter.
 T1W post contrast
images demonstrate
an intensely
enhancing
sellar/suprasellar
mass consistent with
a meningioma
(arrow).
T1
T2
Gd
Germ Cell Tumor: Germinoma
 Germinal cell tumor of
the CNS.
T1
T2
Gd
Gd
Gd
 80-90% of CNS
germinomas are midline
near 3rd ventricle
 May have multiple
locations, such as sellar
and pineal (arrows).
 Case Imaging findings:
 Isointense sellar lesions
on T1 and T2 images
with associated mild
dilatation of the third
ventricle.
 Post contrast images
demonstrate intense
homogenous
enhancement.
 Although not shown,
restriction on DWI is
expected.
Gd
Craniopharyngioma
T1
T1
FLAIR
 Benign, usually partially cystic
sellar tumor.
 Derived from the Rathke pouch
epithelium.
 There are 2 types:
 Adamantinomatous, cystic, in
children.
 Papillary – solid, in adults.
 Common Imaging Findings




Large multilobulated sellar mass.
Frequently >5cm in size.
Ca++ common in children.
MR signal changes with the
contents.
 Case Imaging Findings:
 T1W images demonstrate an iso
to hyperintense cystic lesion with
scattered hypointense dark foci
consistent with Ca++.
 T2W images demonstrate a sellar
lesion with predominant cystic
component.
 Intense epithelial/cyst wall
enhancement with faint
enhancement of solid
components.
Gd
Gd
T2
Chiasm astrocytoma
 Occurrence:
 60% cerebellum.
 25-30% optic
nerve/chiasm.
 10-15% along the third
ventricle or brain stem.
T1
FLAIR
T1
Gd
T2
 Case Imaging findings:
 T1W images demonstrate
a large heterogeneous
predominantly solid mass
in the suprasellar region
isodense to parenchyma.
 T2 and FLAIR images
demonstrate a
heterogeneous mass with
solid components
hyperintense to gray
matter and cystic
components vs. necrosis
isointense to CSF.
 T1 + Gd images
demonstrate an intensely
enhancing suprasellar
mass with central cystic
formation vs. necrosis.
T2*
Pituicytoma
T1
T2
 Rare tumor that arises from
pituicytes in the posterior
pituitary/stalk.
 20% are intrasllar, 40% are
suprasellar, and 40% are
combined.
 Case Imaging Findings:
 T1 isointense lesion.
 T2 hyperintense lesion
 Strong uniform
enhancement.
Case courtesy of
Geoffrey Fletcher, MD
Gd
Gd
Schwannoma – 5th Cranial Nerve
 Benign nerve sheath tumor composed of neoplastic Schwann cells.
 Locations:
 99% of all schwannomas are along cranial nerves.
 95% involve the vestibulocochlear nerve.
 < 1% of all intracranial schwannomas are intraparenchymal.
 Case Imaging findings:
 T1W image demonstrates a parasellar mass along CN5 with classic isointensity.
 T2W image demonstrates a parasellar mass along CN5 with classic hyperintensity.
 Post contrast image demonstrates a parasellar intensely enhancing mass arising from
the CN5.
T1
T2
Gd
Lymphoma
 CNS malignancy due to proliferation of B-cells.
 98%are diffuse large B-cell, non-Hodgkin lymphoma.
 Case Imaging Findings:
 A lateral skull radiographs demonstrates an enlarged osseous sella.
 CT shows an isodense-to-parenchyma lesion with enhancement.
CT-
CT+
Lymphoma (continued)
 T1W images
demonstrate a
large isointense
sellar mass.
 T2W images
demonstrate an
isointense-togray matter
homogenous
mass.
 Contrast
enhanced
images
demonstrate an
enhancing
pituitary mass.
 This lesion was
biopsy to
proven to be
lymphoma.
T1
T2
Gd
Teratoma
 Most common
perinatal brain tumor.
 Male > Female
prevalence.
 Case Imaging
findings:
 T1W images
demonstrate a
hetrogeneous mass
with bright foci of fat
and hypointense
regions consistent
with Ca++.
 T2W images
demonstrate a
heterogeneous
primarily hyperintense
mass (both fat and
fluid components are
bright).
 Contrast enhanced
images demonstrate
an intensely
enhancing mass with
demonstration of
Ca++.
T1
T2
Gd
Metastasis
T1
T1
Gd
T1
Gd
Gd
 Typically breast or lung
cancer.
 6-8% of breast
metastasis.
 Case Imaging Findings:
 T1W image
demonstrates a
sellar/suprasellar mass
isointense to
parenchyma.
 Post contrast images
demonstrate an
enhancing
sellar/suprasellar mass.
 This lesion resected and
found to be metastatic
hepatocellular carcinoma.
Vascular
 Aneurysm
 Pseudoaneurysm
 Kissing Carotids
 Carotid-Cavernous fistula
Carotid Cavernous Aneurysm
CT
 Rare intracranial
aneurysms.
 May cause erosion of
the lateral sellar
margin or
compression of the
pituitary gland.
 Case Imaging
Findings:
 CT images
demonstrate an
isodense intrasellar
lesion.
 T1W MR
demonstrates flow
void in the suprasellar
region, which is the
key diagnostic clue.
 There is compression
of the pituitary gland.
T1
T1
Carotid Cavernous Aneurysm
(continued)
 Cavernous internal
carotid artery (ICA)
aneurysms represent
approximately 3-5% of
all intracranial
aneurysms.
 Can arise from any
segment of cavernous
carotid.
 Most common in the
horizontal ICA segment.
 Case Imaging Findings:
 CTA and Carotid
angiography
demonstrate a large
intrasellar carotid
cavernous aneurysm.
CTA
Carotid Angio
Pseudoaneurysm
CTA
 A pseudoaneurysm is defined
as a focal arterial dilatation not
contained by the normal
arterial wall.
 A postoperative complication
of adenoma or other mass
resection.
 Case Imaging Findings:
 CTA and carotid angiography
demonstrates a hypervascular
lesion within a partially
resected adenoma (orange
arrow) consistent with a
pseudoaneurysm (blue arrow).
Carotid Angio
Kissing carotids
T2
 Medially deviated
supraclinoid/cavernous carotid
arteries are in close
approximation in the midline, or
“kissing” carotids.
 Case Imaging Findings:
 A T2 weighted image
demonstrates closely
approximated cavernous carotid
flow voids consistent with
“kissing” carotids (arrow).
Carotid-Cavernous Fistula
 Nontrauamtic or traumatic
arteriovenous shunt in the
cavernous sinus.
 Case Imaging Findings:
 Arteriogram images
demonstrate a carotid
cavernous fistula.
 Also note postsurgical
craniotomy changes of recent
epidural hematoma evacuation.
Infectious
 Sarcoidosis
 Histiocytosis
 Lymphocytic hypophysitis
 Abscess
Sarcoidosis
T1
Gd
 Systemic disorder with
granulomas in multiple
organ systems
 CNS Locations:
 35% are dural
 35% are leptomeningeal
 30% are within the cranial
nerves, pituitary, or
hypothalamus
Post Therapy Gd
 T1 Isointense
 T2 Hypointense or
hyperintense foci.
 Hypointense when with
fibrocollagenous/gliotic
tissue
 Hyperintense when contains
Inflammatory tissue
 Case Imaging Findings
 T1 image demonstrates an
enlarged infundibulum
(orange arrow).
 Post contrast images
demonstrate an Intensely
enhancing infundibulum
and enlarged VR spaces
(blue arrow).
 Post treatment T1 image
with normal size of the
infundibulum.
Gd
Gd
Histiocytosis
 Proliferation of histiocytes
 Forms granulomas in
hypothalamus and pituitary
gland.
 Presents with:
T1
FLAIR
Gd
Gd
 Visual disturbance
 Endocrine dysfunction
 Diabetes insipidus
 Common Imaging findings:
 Thick pituitary stalk.
 Hypothalamic mass.
 Posterior lobe bright spot
often absent.
 Case Imaging Findings:
 Images demonstrate a T1
hypointense, FLAIR
hyperintense, and intensely
enhancing hypothalamic
chiasmatic mass.
Lymphocytic Hypophysitis
 Caused by granulomatous
inflammation, typically in
post partum women.
 Common imaging findings:
 Thick stalk (> 2 mm).
 Loss of normal tapering ±
enlarged pituitary gland.
 75% show loss of posterior
pituitary "bright spot“ on T1.
 T2 iso to hypointense.
 T1 + Gd with intense
enhancement usually.
 Case imaging findings:
 Case of lymphocytic
hypophysitis with intensely
enhancing enlarged pituitary
gland which is isointense on
T1 and iso to hyperintense
on T2.
 The lesion was biopsy
proven to be lymphocytic
hypophysitis.
T1
T2
Gd
Pituitary Abscess
 Pituitary infections are very rare.
 Infectious route:
 Hematogenous.
 Spread from infected sphenoid
sinus or cavernous sinus.
 Often predisposing mass.
 Presents with headache and
visual disturbance.
 Common imaging findings:
 Similar to microadenoma
 Ring enhancing capsule.
 Case imaging findings:
 A hypoenhancing lesion in the
pituitary, representing abscess
secondary to sphenoid sinus
infection, confirmed at surgery.
Summary
 There is a wide differential that should be considered when
evaluating sellar lesions.
 It is important to correlate these imaging findings with the
clinical presentation.
 Not all pituitary and sellar lesions are adenomas!
Resources
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Patients. J Clin Endocrinol Metab 2011:96:1633–1641
 Gezer A, Paraiba DB, Bronstein MD. Rare Sellar Lesions. Endocrinol
Metab Clin 2008:37:195-211
 Huang BY, Castillo M. Nonadenomatous Tumors of the Pituitary and
Sella Turcica. Topics in Mag Res Img. 2005:16: 289-299
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J Neuroradiol 2012 33: 795originally published online on August 11,
2011