drpradeep1

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Imaging of Sellar , Parasellar and Pineal tumours

• Dr. Pradeep Kumar
• Radiology resident

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D/D Sellar and para sellar mass

• Tumours
• pituitary adenoma  commonest in the adult
  population
• meningioma 
• craniopharyngioma
• hypothalamic astrocytoma / glioma
• chiasmatic astrocytoma
• optic nerve glioma
• germinoma
• chordoma
• dermoid (CNS) / epidermoid / intracranial
  teratoma
• pituitary metastases- breast.gi tract
• Cellular inflitrates
• Langerhans cell histiocytosis (LCH)
• sarcoidosis
• lymphocytic hypophysitis
• Other lesions
• anterior circulation berry aneurysm
• hamartoma (tuber cinereum hamartoma)

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Anatomical approach to D/D
D/D by location
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D/D by location
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Pituitary Adenoma-Imaging of adenomas

• GENERAL FEATURES.
• A sellar or combined intra and suprasellar mass
  that cannot be identified separately from the
  pituitary gland-the most characteristic imaging
  finding.
• CT FINDINGS.
• Bone CT may show an enlarged, remodelled sella
  turcica.
• Macroadenomas are usually isodense with gray
  matter, but cysts (15-20) and haemorrhage (10)
  are common. Calcification is rare (less than 2).
• Moderate heterogeneous enhancement of
  macroadenomas is typical on CECT, but small
  microadenomas may be invisible.

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Macroadenoma MR FINDINGS

• T1-usually isointense with cortex.
• The posterior pituitary bright spot is absent
  (20) or displaced into supradiaphragmatic
  cistern (80).
• Small cysts and hemorrhagic foci are common.
• T2-generally isointense with gray matter but can
  also demonstrate heterogeneous SI .
• T2--Hemorrhagic adenomas bloom.
• T1 C-Most macroadenomas enhance strongly but
  heterogeneously.

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Imaging differential

• TOP DIFFERENTIAL DIAGNOSES Pituitary
  hyperplasia Saccular aneurysm Meningioma
  (diaphragma sellae) Metastasis Lymphocytic
  hypophysitis
• Craniopharyngioma

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Pituitary Microadenoma

• Unless they hemorrhage, small microadenomainappar
  ent in nonenhanced sequences.
• Hypo- isointense on non contrast T1W I
• T2 WI variable, but often a little hyperintense
• D/D Rathkes cyst- Microadenoma enhance whereas
  rathkes cyst are seen as a non enhancing mass
  within the intensely enhancing pitutary gland.

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Protocol advice

• ? Coronal thin-section T1WI obtained during
  contrastinfusion Scans obtained at 5-10 second
  intervals followingrapid bolus injection At
  least 3 sections (3 mm or less, no interslice
  gap)through pituitary gland

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• T1
• sequence small FOV coronal and sagittal
• purpose useful for anatomical depiction, in
  particular, the posterior pituitary bright spot
• T2
• sequence usually coronal, but axial or sagittal
  can also be useful with high resolution/thin
  slices 
• purpose identify blood product or dot sign
  in Rathke's cleft cysts and to visualise the
  diaphragma sellae and arterial flow-voids
• T1 C dynamic
• sequence small FOV coronal, obtained at multiple
  locations through the pituitary gland (e.g. 6) at
  multiple times (e.g. 0, 30, 60, 90, 120 and 180
  seconds)
• purpose useful to identify microadenomas (which
  have delayed enhancement) and identify displaced
  normal pituitary gland by a sellar mass, and to
  help distinguish between a residual or a
  recurrent tumour from postoperative tissues 1
• T1 C delayed
• sequence small FOV coronal and sagittal (same as
  T1 non-contrast)
• purpose valuable to assess the cavernous sinuses
  and to characterise other sellar region tumours
• Some institutions also include some whole brain
  sequences (e.g. DWI/ADC and FLAIR). 

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• Microadenomas enhance more slowly than the normal
  pituitary tissue.
• This discrepancy in enhancement timing can be
  exploited by using thin-section coronal dynamic
  contrast-enhanced scans.
• First min- greatest contrast between gland and PA
  but aftergt20 min tumour appear as hypertense as
  gland
• Between 10-30 of microadenomas are seen only on
  dynamic T1 C imaging

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Imaging differential

• TOP DIFFERENTIAL DIAGNOSES Rathke cleft cyst
  Craniopharyngioma
• Pituitary hyperplasia Other
  nonneoplastic cyst (e.g., pars intermedia cyst)

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Craniopharyngioma

• Most common non glial neoplasm- 6-10.
• benign, partly cystic sellar/suprasellar mass
  that arises from epithelial remnants of Rathke
  pouch.
• primarily suprasellar tumors (75).
• A small intrasellar component is present in
  20-25 of cases
• Solitary lesions.
• Size few mm-several cm. Lesions larger than five
  cms are common.
• Giant CPs may extend into both anterior and
  middle cranial fossa.
• Two types of CPs Adamantinomatous -90 and
  papillary- 10 .

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IMAGING

• GENERAL FEATURES.
• Partially calcified, mixed solid and cystic
  extraaxial suprasellar mass in a child.
• CT FINDINGS.
• Adamantinomatous CPs follow a rule of ninety,-
  90 are mixed cystic/solid, 90 are calcified,
  and 90 enhance.
• Papillary CPs rarely calcify, mostly solid.
• cystic, lobulated suprasellar mass with a solid
  mural nodule
• Nodular or rim calcification and nodular or rim
  enhancement in CECT

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MR FINDINGS

• Multiple cysts are common, and intracystic fluid
  within each cyst varies from hypo to hyperintense
  compared to brain on T1WI. High signal on T1-
  high protein concentration /- blood degradation
  products.
• T2WI and FLAIR-- CP cysts are variably
  hyperintense.
• Compressed pituitary gland.
• C -- The cyst walls and solid nodules shows
  Strong and heterogenous contrast enhancement
• MRS
• shows a large lipid-lactate peak, characteristic
  of the cholesterol and lipid constituents of a CP.

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Midline sagittal section shows a solid mass
filling the third ventricle. Papillary
craniopharyngioma Sagittal T1 C scan in a
37-year-old man shows a solidly enhancing mass in
the third ventricle, Papillary craniopharyngioma.
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Imaging differentials

• Rathkes cleft cyst
• Hypothalamic/chiastmatic astrocytoma
• Hypothalamic hamartoma
• Pituitary adenoma
• Dermoid cyst
• Epidemoid cyst

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Imaging of meningioma

• CT FINDINGS.
• NECT 75 mild to moderately hyperdense compared
  to cortex . 25 -isodense.
• Peritumoral vasogenic edema, seen as confluent
  hypodensity in the adjacent brain -- 60 of all
  cases.
• 25--calcification.
• Bone CT -Hyperostosis is often but not invariably
  associated with tumor invasion.
• CECT. The vast majority of meningiomas enhance
  strongly and uniformly.

hyperdense well defined mass in suprasellar
region.
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MRI

• T1WI
• Typically iso- to slightly hypointense compared
  to cortex
• T2WI--
• Iso- to moderately hyperintense compared to
  cortex .
• The CSF-vascular cleft
• FLAIR.
• SI varies from iso to hyperintense.
• T2 GRE-
• depict intratumoral calcification
• T1 C-- Over 95 enhance strongly and
  homogeneously.
• A dural tail--
• dural tail -- represents benign, reactive
  dural thickening.
• DWI-- Most meningiomas do not restrict on DWI

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Suprasellar meningioma. (a) Parasagitta
T1-weighted MR image -relatively hypointense
suprasellar mass (black arrow).The hypophysis
(open arrow) is compressed within the sella
turcica. (b) Axial T2weighted image reveals a
somewhat heterogeneous but principally
hypointense mass. (c) On enhanced axial T1
-weighted image, strong and near homogenous enh.
Vascular flow void
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Imaging differential

• Pituitary macroadenoma
• Craniopharyngioma

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Rathkes Cleft cyst Imaging

• CT FINDINGS.
• NECT- well-delineated round or ovoid mass within
  or just above the sella turcica. 75 of RCCs are
  hypodense on NECT whereas 20 are mixed hypo- and
  isodense. 5-10 are hyperdense . Ca uncommon.
• MR FINDINGS.
• SI varies with cyst contents.
• T1WIHalf are hypointense and half are
  hyperintense
• T2WI-- Majority hyperintense 25-30 are iso
  to hypointense ,intracystic nodule- 40-75 of
  cases
• FLAIR-- almost always hyperintens.
• C -An enhancing rim (claw sign) of compressed
  pituitary gland can often be seen surrounding the
  nonenhancing cyst.

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• very hyperintense lesion on FLAIR.
• Sagittal T1 C scan demonstrates a classic
  claw sign formed by a thin rim of compressed
  pituitary gland image that surrounds the
  nonenhancing mass.
• Rathke cleft cyst was confirmed at surgery.

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Imaging differential

• TOP DIFFERENTIAL DIAGNOSES Craniopharyngioma
  Cystic pituitary adenoma Arachnoid cyst Other
  nonneoplastic cyst (pars intermedia, colloid
  cyst)

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• HYPOTHALMIC HAMARTOMA GENERAL FEATURES
• CT FINDINGS.
• NECT -iso- to slightly hypodense homogenous mass
  compared to brain. cysts seen in larger HHs.
• HHs do not enhance on CECT.
• MR FINDINGS.
• Signal intensity is usually isointense to normal
  gray matter on T1WI and iso- to slightly
  hyperintense on T2/FLAIR.
• C -- do not enhance.

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Chordoma

• uncommon malignant tumours that account for 1 .
• originate from embryonic remnants of the
  primitive notochord.
• Fungating mass from clivus
• May calcify
• CT expansile soft-tissue mass with moderate
  enhancement.
• T1
• intermediate to low signal intensity
• small foci of hyperintensity (intratumoral
  haemorrhage or a mucus pool)
• T2 most exhibit very high signal 
• T1 C (Gd) heterogeneous enhancement with a
  honeycomb appearance.
• GE (gradient echo) confirms haemorrhage if
  present with blooming

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Summary of sellar and suprasellar tumor

• Macroadenoma
• Microadenoma
• Meningioma
• Craniophyrngioma
• Rcc
• Chordoma
• Dermoid
• Epidermoid

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Pineal Gland

• Size 10 to 14 mm
• Composed of pineocytes and astrocytes separate by
  fibrovscular stroma
• Tumors may cause headache, hydrocephalus,
  perinaud syndrome, precocious puberty and pineal
  apoplexy.

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Pineal gland tumors

• Pineal parenchymal tumors
• Pineocytoma (Grade I)
• Pineal parenchymal tumor of intermediate
  differentiation (PPTID) (Grade II/III)
• Pineoblastoma (Grade IV)
• Papillary tumor of pineal region
• Other tumors that may have pineal location
• Trilateral retinoblastoma
• Germ cell tumors( Germinoma, teratoma, embryonal
  ca, yolk sac tumor, choriocarcinoma, mixed)
• Pineal cysts, lipoma, dermoid, epidermoid,
  meningioma

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Pineocytoma

• Slow-growing lesion1460 of pineal
  parenchymal neoplasms. (Mean age 38 years)
• CSF dissemination- rare.
• CT well demarcated, usually less than 3 cm, and
  iso- to hyperattenuating lsions
• Expand and obliterate pineal architecture,
  exploding the normal pineal calcification
  toward the periphery.
• MR well-circumscribed hypo- to isointense on T1-
  and hyperintense on T2-weighted images. Avid,
  homogeneous enhancement
• Occasional Cystic or partially cystic changes may
  occur.
• Hemorrhage into the lesion (pineal apoplexy) -
  rare

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Pineocytoma in a 35-year-old man with a history
of headaches. Sagittal postcontrast T1-weighted
MR image shows an avidly enhancing mass in the
pineal region with resultant hydrocephalus.
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Pineal apoplexy Axial plain CT image shows a
hyperattenuating lesion with a posterior cystic
component in the pineal region with anterior
displacement of the pineal calcifications. A
hematocrit level is noted within the cystic
component (arrow), a finding consistent with
hemorrhage. Hydrocephalus is also present.
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Imaging differentials

• Differential Diagnosis Benign pineal cyst (may
  be indistinguishable) Germinoma ("engulfs"
  Ca, male adolescents) PPTID (more "aggressive
  looking"

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Pineal parenchymal tumor of intermediate
differentiation(PPTID)

• WHO grade III tumors
• Imaging findings similar to that of pineocytoma
• Diagnosis can only be made after histoloical
  examination.

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Imaging differentials

• Differential Diagnosis Pineocytoma gt gt
  pineoblastoma Germinoma

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Pineoblastoma

• Highly malignant WHO grade IV lesions (40 of
  pineal parenchymal tumors
• occur mostly in the first 2 decades but can occur
  at any age
• CSF dissemination- common
• CT large (typically 3 cm), lobulated, typically
  hyperattenuating mass. The pineal calcifications
  may appear exploded at the periphery of the
  lesion. Obstructive hydrocephalus- 100 cases.
• MR heterogeneous in appearance Necrotic regions
  and hemorrhage may be present. Extensive cystic
  change rarely occurs

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Imaging differentials

• The major differential diagnosis of PB is PPTID.
  PBs tend tooccur in children. CSF dissemination
  at diagnosis is morecommon. Germinoma may mimic
  PB on imaging studies, as italso frequently
  demonstrates CSF spread. Germinomas aremore
  common in adolescent and young adult male
  patients.They tend to "engulf" rather than
  "explode" pinealcalcifications.Nongerminomatous
  malignant germ cell tumors are aheterogeneous
  group of tumors that may be indistinguishableon
  imaging studies from PBs. Elevated tumor markers
  such asa-fetoprotein and ß-human chorionic
  gonadotropinallusually negative in germinoma
  and PBare helpful inestablishing the diagnosis

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• Imaging differentials
• PPTID
• Germinoma
• Non germinomatous malignant germ cell tumors
• Pineal anlage tumors

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Papillary Tumor of the Pineal Region

• Rare tumor- probably Grade II/III
• PTPRs are well-circumscribed lesions with
  variable signal intensity on T1, high signal
  intensity on T2-weighted images, and enhancement
  on postcontrast images.
• Cystic areas are commonly present.
• Hyperintensity on T1-weighted images has been
  described, which is hypothesized to be related to
  secretory inclusions containing protein or
  glycoprotein

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PTPR in a 17-year-old girl (a) Axial T2-weighted
MR image shows a small, heterogeneous, cystic and
solid lesion in the pineal region. Hydrocephalus
is present. (b) Postcontrast T1-weighted MR image
shows enhancement of the solid portion of the
lesion.
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Imaging differentials

• Differential Diagnosis
• Pineal parenchymal tumor of intermediate
  differentiation Germinoma

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Trilateral retinoblastoma in a 2-year-old girl
with a history of enucleation for retinoblastoma.
(a) Axial postcontrast fat-saturated T1-weighted
MR image shows a focus of enhancement along the
medial wall of the left globe a finding
consistent with retinoblastoma. The right globe
was removed due to retinoblastoma, and a
prosthesis is in place. (b) Axial postcontrast
T1-weighted MR image shows an associated
enhancing pineoblastoma with resultant
hydrocephalus.
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Summary of pineal tumor

• Pineoblastoma
• Pineocytoma
• Pineal parenchymal tumor of intermediate
  differentiation(PPTID)
• Papillary Tumor of the Pineal Region
• Germinoma

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Normal Pineal Gland Frequently calcifies. Attenuation is otherwise equal to that of gray matter. Pineal lacks blood-brain barrier, enhances uniformly with contrast administration May appear isointense to gray matter. May appear isointense to gray matter. May appear isointense to gray matter. No restricted diffusion. Uniformly enhances
Pineoblastoma Hyperdense. Calcifications may explode toward the periphery. May hemorrhage. Usually large and lobulated. Demonstrates moderate homogeneous enhancement. (No image available) Heterogeneous with the solid portion appearing hypo- to isointense. Heterogeneous, may be hyperintense relative to gray matter. Demonstrates high signal. Hyperintensity within the lesion, a finding suggestive of high cellularity. (No image.) Heterogeneous enhancement within the mass.
Pineocytoma Hyperdense. Calcification may engulf the pineal. Demonstrates moderate homogeneous enhancement. Lobular lesion which may be hypointense compared to brain parenchyma, but higher than CSF. Hyperintense lobular lesion. Hyperintense lobular lesion. Areas of restricted diffusion within the lesion. Avidly enhancing mass
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Germinoma Demonstrates intense homogenous enhancement. (No image available.) Iso- or hypointense to grey matter. Iso- or hyperintense to grey matter. Iso- or hyperintense to grey matter. High signal intensity in the lesion, a finding indicative of high cellularity. (No image available) Homogeneous enhancement
teratoma Variable. May contain fat, calcification, teeth.Hemorrhage is possible. Tooth is diagnostic. May demonstrate relative homogeneous enhancement of the noncalcified solid portions of the tumor. However, the cystic region does not enhance. Heterogeneous mass that may contain varying amounts of hyperintense lipid material. Cystic regions may have higher signal than that of CSF because of proteinaceous material.     May show enhancement of the soft tissue portions of the lesion.
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• Thank
  You