Making Sense of Sellar Region Pathology: Image-based

Diagnostic Algorithm

Ammar Chaudhry, MDRajesh Gupta, MDLuboslav Woroch, DOAlexander Filatov, MDRobert Peyster, MDLev Bangiyev, DO

eEdE-69SN: 960

Disclosures

• No relevant disclosures

Objective

• Review of anatomy of sellar and parasellar regions

• Review common indications for imaging of the pituitary gland

• Discuss imaging techniques of the pituitary gland

• Review common pathology of the pituitary gland and the adjacent structures

• Image-based diagnostic algorithm

Sphenoid Bone Anatomy

• Pituitary fossa• Tuberculum sellae• Optic nerve canal• Chiasmatic sulcus• Superior orbital fissure• Anterior clinoid• Posterior clinoid• Greater wing of sphenoid• Lesser wing of sphenoid• Planum sphenoidale

Pituitary Gland Anatomy• Lies within sella turcica• Composed of two major parts– Anterior lobe – Adenohypophysis• Pars distalis – bulk of the gland,

hormone secretion• Pars intermedia• Pars tuberalis• GH, TSH, ACTH, prolactin, LH, FSH

– Posterior lobe – Neurohypophysis• Vsopressin, oxytocin

• Laterally bounded by cavernous sinus• Optic chiasm superiorly• Diaphragma sella

http://mystatdx.com

Embryology• Posterior lobe

– Neural primordia– Outpouching from the third

ventricle– Anatomic extension of the

CNS– Specialized glial cells

pituicytes• Anterior lobe

– Derives from the oral ectoderm Rathke’s pouch

– Gives rise to pars distalis and tuberalis

Blood Supply

• Posterior lobe supplied by inferior hypophysial arteries

• Anterior lobe – Little or no arterial supply– Portal venous system from the

pituitary stalk– Venous blood from posterior

pituitary– Humeral regulation from the

hypothalamus, posterior pituitary, and substances in the peripheral circulation

Indications for Imaging

Imaging of the Pituitary Radiol Clin N Am 49 (2011) 549–571

Imaging

• MR Protocol

Imaging

• MR– Demonstrate relationship to chiasm

and cavernous sinus– Distinguishing solid, cystic, and

hemorrhagic components– Vascular structures– Anterior lobe is isointense to brain

on T1WI and T2WI– Posterior lobe is bright on T1WI and

lower intensity on T2WI

Imaging

• Enhancement• Size

– children (<12 years) : 6mm (upper surface flat or slightly concave)

– puberty : 10mm (upper surface convex; more striking in females)

– young adult– male : 8mm– female : 9mm– pregnancy : 12mm– older adult ( > 50 years) : gradually

decreases in size

Imaging

• CT– Calcifications– Bony septa assessment for transsphenoidal pre-

surgical planning– Involvement of the adjacent osseous structures– Contraindications to MRI

Common Pathology• Macroadenoma• Microadenoma• Rathke’s cleft cyst• Craniopharyngioma• Langerhans Cell Histiocytosis• Germinoma• Apoplexy• Empty sella• Hypophysitis• Meningioma• Optic glioma• Hamartoma• Arachnoid cyst• Epidermoid• Lipoma• Ectopic posterior pituitary bright spot• Aneurysm• Sarcoid• Base of the skull tumors

Location Based AlgorhithmParasellar

Suprasellar Enhancing

Craniopharyngioma Germ Cell Tumors Menigioma Aneurysm

Non-enhancing Hamartoma

Pituitary Stalk Lymphocytic Hypophysitis Langherhans Histiocytosis Germ Cell Tumors Sarcoid Mets Ectopic Posterior Pituitary Lipoma

Clivus Chordoma Nasopharyngeal Carcinoma Mets

Chiasm Glioma

SellarExpanding Sella Turcica

Pituitary MacroadenomaNon-expansile

Intensity Hyperintense T1

Rathke’s Cleft Cyst (if protein)

Dermoid Cyst (children)

Hyperintense T2 Meningioma Rathke’s Cleft

Cyst Hypointense T1

Pituitary Microadenoma

Hypointense T2 Pituitary

Apoplexy

Macroadenoma

• 55-year-old female with history of glaucoma patients was followed with serial visual field testing. The visual field deteriorated and began to show a bitemporal hemianopsia.

Cor T2WI Sag Pre T1WI Cor Pre T1WI Cor Post T1WI

• Similar imaging characteristics as microadenoma• Normal pituitary tissue often not identified• Expands the sella• “Snowman” appearance where the waist is the imprint from rigid

dura• May extend into the suprasellar region and compress the chiasm• May invade the cavernous sinus

Microadenoma

• 19 yo female with hyperprolactinemia

Dyn Cor Pre T1WI Dyn Cor Post T1WI • Approximately 10% to 15 % of all intracranial neoplasms• Most common sellar tumor• Benign• Classified based on size

– Microadenomas <10mm – Macroadenomas >10mm

• Clinically classified based on endocrinological activity or lack– Functional pituitary adenomas usually secrete single hormone– Prolactin most common followed by GH and ACTH

• Microadenomas are hypovascular compare to normal pituitary tissue

Invasive Pituitary Adenoma• Clival invasion is rare but potentially significant complication of pituitary adenoma• Difficult to detect on MR imaging, easily seen on CT• Risk factor for clival invasion:

• female sex • large tumor volume • null-cell subtype • Larger tumor volume correlated with null-cell subtype (Mann-Whitney U test, P = .006), incidence of clival invasion (P < .001), and

extent of clival invasion

• Clival invasion was associated with a significantly higher ratio of operative complications and recurrence

Pituitary Apoplexy

• 40 yo male with progressive visual decline in the right eye over several weeks, presents with rapid visual loss, slight droopiness of the right eye, and severe headache. Pituitary adenoma with hemorrhage.

Sag Pre T1WI Ax T2WI Cor Post T1WI

Lack of direct arterial supply to anterior pituitary lobe makes it susceptible to ischemia with or without hemorrhage

Clinical syndrome

HeadacheVisual changesOphthalmoplegiaMental status change

Underlying adenoma is often present

Empty Sella• Patulous diaphragma

sellae• Aging• Pseudotumor cerebri• Infarction• Surgery• Radiation therapy• Hypopituitarism is rare

Rathke’s Cleft Cyst

25 yo female with headaches

Sag Pre T1WI Sag Post T1WI Cor T2WI Cor Post T1WI

• Derive from Rathke’s pouch (primitive oral ectoderm)• Lined by single layer of columnar or cuboidal epithelium• Frequently asymptomatic• May present with bitemporal hemianopsia or pituitary

dysfunction• Intrasellar and non-invasive• May contain serous or mucoid material

– Serous – hypodense on CT, T1 hypointense and T2 hyperinstense– Mucoid – hyperdense on CT, T1 hyperintense

• Rarely calcify• May demonstrate mild enhancement of the wall

• 8 yo female presented with progressive double vision and papilledema• Left CN VI palsy

• Adamantinomatous type craniopharyngioma

• 73 yo female with headache and visual disturbance

• Papillary craniopharyngioma

Ax Pre T1WI

Cor Post T1WI

Sag Post T1WI

Ax Post T1WI

Ax T2WI

Craniopharyngioma• Benign neoplasm arising from

squamous epithelial remnants of Rathke’s pouch

• Tend to recur and invade adjacent structures

• Commonly present with – Headaches – Endocrine dysfunction – Visual disturbance

• Bimodal age at presentation – 5 to 14 years in children – 65 to 74 years in adults

• Usually suprasellar, but may extend into the sella– Preachasmatic – visual disturbance– Retrochiasmatic – increased ICP,

compression of the hypothalamus and protrusion into the third ventricle

• Imaging characteristics– Vary in size and composition– Cystic and/or solid

• CT– Enhancing solid/cystic mass– Calcifications +/-

• MRI– T1WI – vary intensity depending on

contents (proteinaceous debris, cholesterol, and hemoglobin)

– Enhancement of the solid component

– T2WI – predominantly hyperintense– Calcifications are hypointense on all

pulse sequences

Histopathologic Types of Craniopharyngiomas

Adamatinous Squamous-Papillary

Location Suprasellar Intrasellar/suprasellar or suprasellar

Age Children, occasionally adults Adults

Tissue structure Predominantly cystic Predominantly solid

T1 without contrast Hyperintense cysts typical If ever, hypointense cysts

Shape Lobulated Spherical

Encase vessel Yes No

Tumor recurrence +++ +

Calcifications +++ +

Meningioma

25 yo female with history of meningioma

Sag Pre T1WI

Ax Post T1WI

Cor Post T1WISag Post T1WI

Ax T2WI

• May arise from the tuberculum sellae, anterior clinoid, diaphragma sellae, planum sphenoidale, cavernous sinus, and upper clivus

• Commonly present with progressive visual symptoms• CT – hyperdense mass with homogenious enhancement• MRI – T1 isointense, T2 iso-hyperintense, avid

enhancement• Distinguished from pituitary adenoma by

– Normal size of the sella turcica– Identification of the normal pituitary tissue – Can invade cavernous sinus with narrowing and/or occlusion of ICA – Hyperostosis

Optic Glioma

6 yo male with progressive left eye vision loss over a year

Ax Pre T1WI Cor Pre T1WI Cor Post T1WI Cor Post T1WI

Cor T2WI

• Tumor of childhood• Majority benign and slow growing• Often associated with NF1• Separate from pituitary gland• T1 isointense and T2 hyperintense with

variable enhancement• Presence of cystic component suggests JPA

Germ Cell Tumor• Lesion of childhood and young adults• Germinoma is the most common type• 20 % in sellar/suprasellar region and remainder in

pineal region• Commonly present with DI, hypopituitarism, and

optic chiasm compression• CT – hyperdense and homogeneously enhancing

• MR Findings– T1WI – Iso-/hyperintense to gray matter– T2WI – Iso-/hyperintense to gray matter– Calcification, hemorrhage (rare)– DWI: Restricted diffusion due to high

cellularity– Strong, homogeneous enhancement, ± CSF

seeding, ± brain invasion

Sag T2WI Sag Pre T1WI Sag Post T1WI Cor Post T1WI

• 21 yo male presented with progressive vomiting, polyuria and polydipsia for months, progressive loss of his peripheral vision in both eyes bitemporal inferior quadrantsanopsia, panhypopituitarism and diabetes insipidus

• HCG serum ↑, BhCG CSF ↑ ↑ ↑

Lymphocytic Hypophysitis

23 yo female with hypopituitarism

Sag Post T1WI Cor Post T1WICor T2WI Sag Pre T1WI

• Inflammatory disease of the pituitary• Can involve infundibulum• Young women during late pregnancy or postpartum• Imaging shows enlarged enhancing pituitary gland and thickened

infundibulum• May regress spontaneously or with steroids

Hamartoma of the Tuber Cinereum

2 yo female with gelastic sezures consisted of laughing, turning her head to left side and tonic motor activity of the extremities

Sag Pre T1WI Sag Post T1WI Ax FLAIR Ax T2WI

• Congenital non-neoplastic heterotopias• Known cause of

– Precaucious puberty due to secretion of LH-releasing hormone– Gelastic seizures may be related to connection of the lesion with limbic system or possibly presence

of other abnormalities (callosal agenesis, heterotopias, and microgiria)• Just anterior to mamillary bodies• T1 isointense and T2 hyperintense to gray matter• Do not enhance, calcify, or contain cysts

Langerhans Cell Histiocytosis

13 yo male presented with diabetes insipidus

Sag Post T1WI Cor Post T1WI

• Proliferation of Langerhans cell histiocytes forming granulomas within any organ system

• Etiology: Uncertain: Inflammatory ↔ neoplastic• Peak age at onset 1 year (isolated), 2-5 years (multifocal disease)• Common presentation – DI, ± visual disturbance, ± hypothalamic

dysfunction• On imaging thick enhancing infundibulum, absent posterior pituitary

bright spot

Lymphocytic Hypophysitis

23 yo female with hypopituitarism

Sag Post T1WI Cor Post T1WICor T2WI Sag Pre T1WI

• Inflammatory disease of the pituitary• Can involve infundibulum• Young women during late pregnancy or postpartum• Imaging shows enlarged enhancing pituitary gland

and thickened infundibulum• May regress spontaneously or with steroids

Granulomatous Disease

• Sarcoid, TB, Wegener etc.• Cranial nerve involvement• Cannot be differentiated by imaging• Sarcoid may present with sellar or suprasellar mass

and masquerade as pituitary adenoma or meningioma

Epidermoid

• Cystic lesion filled with keratin• Signal characteristics are similar to CSF on T1 and T2, however

not FLAIR• Show restricted diffusion• Usually do not enhance• Insinuate throughout the suprasellar region

Ax T2WI Ax FLAIR Sag Pre T1WI Ax DWI

Lipoma

• Incidentally found lipoma. Patient was imaged for headache.

Sag Pre T1WI

• Characterized by T1 hyperintensity due to fat

• Lipomas are usually circumscribed

• Teratomas and dermoids can grow large and compress adjacent structures

• Teratomas may contain calcification or ossification

Chordoma

58 yo male with jerking motions during sleep and progressive memory loss. No visual changes or endocrine symptoms

Ax NECT Sag Pre T1WI Sag Post T1WI

Cor T2WI

• Imaging– CT

• Soft tissue mass with bone destruction and calcifications

– MRI• T1WI – isointense to brain parenchyma with

hypointense calcifications • T2WI – hyperintensity is a rule• Enhance

Metastasis

• 53 yo female with history of breast CA

Ax Pre T1WI Ax T2WI Sag Post T1WI

Aneurysm

• 51 yo male with acute onset of headache and left CN III palsy

NECT Ax T2WI Ax Pre T1WI Cor Post T1WI

AP Lt CCALat Lt CCA

CONCLUSION Location

Sellar

Intensity

Isointense T1

Hypo T2

Pit apoplexy-subacute

(hyper T1/T2)-comp of adenoma

Hyperintense T2

Gender

Both

Pituitary Macroadenoma

- >10 mm-mild

enhancement

Female

Enhancement

Intense

Meningioma

-Calcify

-can be

supras ellar

Rare

Rathke’s Cleft cyst

Hypointense T1

Pituitary Micr oadenoma- <10 mm

-hypoenhancement

Hyperintense T1

Gender

Male

Dermoid Cyst

-Children-Calcify

Female

Rathke’s cleft cyst

-if protein content-Adults

Eccentric mass (cavernous carotid

aneurysm)

Suprasellar

Heterogeneous

Craniopharyngioma-cystic – high T1/T2-solid – enhances

-bimodal age-calcify

Homogeneous

Germ Cell Tumors-iso T1/T2-uniform

enhancement

Pituitary Stalk

Young age

Histiocytosis (Eosinophilic Granuloma)

Intensity

Hypo

T1/hyper T2

Mets-enhances

Iso T1/T2

Sar co i d-en h an ces

-femal e

Lymphocytic Hypophysitis

Chiasm/Hypothalamus

Enhancement

Yes

Glioma-iso T1/hyper T2

-young age-hyperintense FLAIR

No

Hamartoma-iso T1/T2

-floor of 3rd vent

End PresentationPlease send correspondence to: Ammarchaudhry84@gmail.com

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