SELLAR AND SUPRASELLAR MIMICS A CASE REVIEW SERIES

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SELLAR AND SUPRASELLAR MIMICS A CASE REVIEW SERIES ANGELA SNEIDER, D. O. , NATALYA

SELLAR AND SUPRASELLAR MIMICS A CASE REVIEW SERIES ANGELA SNEIDER, D. O. , NATALYA NAGORNAYA, M. D. CHARIF SIDANI M. D. , RITA BHATIA, M. D. Presentation #e. Ed. E-140 -7366

Disclosures The authors have no disclosures

Disclosures The authors have no disclosures

Purpose Mimics of typical sellar and suprasellar lesions are relatively rare and can present

Purpose Mimics of typical sellar and suprasellar lesions are relatively rare and can present a diagnostic dilemma with vital therapeutic implications. The authors report a pictorial review of various common and uncommon mimics of sellar and suprasellar lesions. Also included are atypical presentations of common lesions.

Approach/Methods Retrospective case review of patients presenting to the Department of Radiology at Jackson

Approach/Methods Retrospective case review of patients presenting to the Department of Radiology at Jackson Memorial Hospital and the University of Miami MRI Center. Included are atypical lesions of the sellar and suprasellar spaces, as well as more common lesions found at these locations with atypical imaging characteristics.

Findings We present multiple cases in which uncommon sellar or suprasellar lesions have the

Findings We present multiple cases in which uncommon sellar or suprasellar lesions have the appearance of other more often encountered masses of this location. We also present atypical imaging characteristics of more common lesions.

Case #1

Case #1

Optic Chiasm Cavernoma Clinical � May be Asymptomatic (>30% become symptomatic, usually in 20

Optic Chiasm Cavernoma Clinical � May be Asymptomatic (>30% become symptomatic, usually in 20 s or 30 s) � Behave as all cavernomas � Hemorrhage rate of all cavernomas: 0. 7 -1. 7%/lesion/year 20% familial, autosomal dominant Imaging � Acute: Visual disturbance, subarachnoid hemorrhage, seizures Chronic: Progressive visual loss, headache, endocrine dysfunction CT: Well-delineated hyperdense mass +/- calcification, negative in up to 50% MRI: Popcorn appearance on T 1 and T 2 common, hypointense hemosiderin ring on T 2, blooming on GRE, minimal/no enhancement, look for associated developmental venous anomaly DDx: AVM, aneurysm, optic glioma, craniopharyngioma, pituitary apoplexy Tx: Somewhat controversial; 50% stable vision and 50% progressive visual loss � � With resection (partial or complete): 87% improved vision Stereotactic radiation therapy proposed but not well documented; anterior optic pathway sensitive to radiation “Cavernous Malformations, ” American Association of Neurological Surgeons, 2008 Jul. http: //www. aans. org/Patient%20 Information/Conditions%20 and%20 Treatments/Cavernous%20 Malformations. aspx Accessed September 22, 2014 Crocker, M, De. Souza R, King A, at el. Cavernous Hemangioma of the Optic Chiasm: A Surgical Review, Skull Base 2008: 18(3): 201 -12.

Case #2

Case #2

Case #2 (continued) Early Right ICA Late Right ICA

Case #2 (continued) Early Right ICA Late Right ICA

Arteriovenous Malformation Clinical � � Imaging � � About half present with headache secondary

Arteriovenous Malformation Clinical � � Imaging � � About half present with headache secondary to hemorrhage More than half have an associated aneurysm ~1/4 have associated seizures Patients may have progressive neurologic dysfunction secondary to related hypoperfusion or microhemorrhage “Bag of worms, ” tangle of vessels MRI: “Honeycomb” of flow voids, may have blooming on GRE if hemorrhage, nidus enhances, enlarged feeding artery/-ies and early draining vein(s) DDx: Other vascular malformation such as dural AV fistula or cavernoma, vascular neoplasm/metastasis, meningioma Tx: � � � Embolization Stereotactic radiation therapy Surgical resection Spetzler-Martin score utilized (surgery typically avoided with a score of 4 or 5) Based on size of nidus, venous drainage and involvement of eloquent cortex Geibprasert S, Pongpech S, Jiarakongmun P, et al. Radiologic assessment of brain arteriovenous malformations: what clinicians need to know. Radio. Graphics 2010: 30(2): 483 -501 Santos M, Demartini Z, Matos L, et al. Angioarchitecture and clinical presentation of brain arteriovenous malformations. Arq Neuropsiquiatr 2009: 67(2 A): 316 -21

Case #3

Case #3

Case #3 (continued)

Case #3 (continued)

Bilateral Petrous Apex ICA Aneurysms, Partially Thrombosed Clinical � � Imaging � � �

Bilateral Petrous Apex ICA Aneurysms, Partially Thrombosed Clinical � � Imaging � � � May present with sensorineural hearing loss (most common), cranial neuropathy, pulsatile tinnatus, epistaxis, stroke Underlying causes (i. e. connective tissue disorder) are atypical Possible causes of acquired aneurysm: radiation therapy to the skull base, prior trauma, skull base infection Important to evaluate for additional intracranial aneurysms, especially with those suspected to be congenital CT: Osseous erosion, curvilinear calcification, enhancement MRI: T 1 and T 2 heterogeneous, may see a swirl pattern on T 2, clot may bloom on GRE, enhancement CTA preferred diagnostically; MRA can demonstrate hyperintense T 1 signal with cholesterol granuloma that appears as flow-related signal DDx: Cholesterol granuloma, fibrous dysplasia, encephalocele, petrous apicitis Tx: Balloon trapping, stent placement, sacrifice of ICA with ECA to MCA bypass Chapman P, Shah R, Curé J, et al. Petrous apex lesions: pictorial review. American Journal of Roentgenology 2011: 196: WS 26 -37 Razek A, Huang B. Lesions of the petrous apex: classification and findings at CT and MR imaging. Radiographics 2012: 32(1): 151 -73

Case #4 a

Case #4 a

Case #4 b

Case #4 b

Macroadenoma (mimicking tuberculum sella meningioma (4 a) & craniopharyngioma (4 b)) Clinical � �

Macroadenoma (mimicking tuberculum sella meningioma (4 a) & craniopharyngioma (4 b)) Clinical � � � Imaging � � Typically present with endocrinopathy or visual disturbance Most common suprasellar mass in adults “snowman” appearance End-organ failure in adolescent males can lead to pituitary hyperplasia with an adenomalike mass No separate pituitary gland identified MRI: T 1 and T 2 isointense, heterogeneously enhancing By definition, >10 mm; if >4 cm, giant macroadenoma May appear invasive, however pituitary carcinoma is extremely rare DDx: Pituitary hyperplasia, metastasis, meningioma, craniopharyngioma, aneurysm Tx: Surgical resection, typically transsphenoidal � � Transsphenoidal resection likely to fail when lesions are solid and enhancing with restricted diffusion ~35% recurrence rate over 20 years Boxerman J, Rogg J, Donahue J, et al. Preoperative MRI evaluation of pituitary macroadenoma: imaging features predictive of successful transsphenoidal surgery. Amer J Roentgen 2010: 195(3): 720 -8 Ehirim P, Kerr D, Cohen A. Primary hypothyroidism mimicking a pituitary macroadenoma. Pediatric Neurosurgery 1998: 28(4): 195 -7

Case #5

Case #5

Macroadenoma with Apoplexy Clinical � � Typically present with sudden onset headache, severe nausea,

Macroadenoma with Apoplexy Clinical � � Typically present with sudden onset headache, severe nausea, visual disturbance, altered mental status Most patients have an underlying macroadenoma Imaging � � � ~1% of macroadenomas will hemorrhage Usually middle-aged, more common in males; peripartum females also at risk CT hyperdensity, MRI blooming within the sella; rim enhancement suggests underlying hemorrhage; may have associated subarachnoid hemorrhage MRI characteristics depend on age of hemorrhage; acute hemorrhage is T 1 isointense and T 2 hypointense; may see diffusion restriction early Commonly see associated dural thickening/enhancement and/or mucosal thickening of the sphenoid sinuses DDx: Craniopharyngioma, Rathke cleft cyst, nonhemorrhagic macroadenoma, aneurysm, abscess Tx: Surgical decompression/resection of underlying macroadenoma, supportive therapy Boellis A, Napoli A, Romano A, et al. Pituitary apoplexy: an update on clinical and imaging features. Insights into Imaging 2014: 5(6): 753 -62 Semple P, Jane J, Lopes M, et al. Pituitary apoplexy: correlation between magnetic resonance imaging and histopathological results. Journal of Neurosurgery 2008: 108(5): 909 -15

Case #6 (two different patients)

Case #6 (two different patients)

Meningioma Clinical � � � Imaging � � 1/3 of all incidental intracranial neoplasms

Meningioma Clinical � � � Imaging � � 1/3 of all incidental intracranial neoplasms ~3 -10% of meningiomas arise from the tuberculum sellae More common in women, typically between 30 -60 years old Sx: Headache, visual disturbance, anosmia Up to 2/3 involve at least one of the optic canals CT: 3/4 hyperdense, 1/4 at least partially calcified, underlying bone hyperostotic MRI: Hypo- to isointense on T 1 and T 2, look for dural tail, early and prolonged enhancement (mother-in-law sign) DDx: Macroadenoma, metastasis, sarcoid, nerve sheath tumor Tx: Watchful waiting if asymptomatic, surgical resection if symptomatic � � Immediate postoperative improvement in vision in ~2/3 presenting with visual disturbance Resection complicated by proximity to adjacent arteries, optic nerves/chiasm and hypothalamus Sklar E, Schatz N, Glaser J, et al. Optic tract edema in a meningioma of the tuberculum sellae. AJNR Am J Neuroradiol 2000: 21: 1661 -63 Nakamura M, Roser, F, Struck M, et al. Tuberculum sellae meningiomas: clinical outcome considering different surgical approaches. Neurosurgery 2006: 59(5): 1019 -28 Mahmoud M, Nader R, Al-Mefty O. Optic canal involvement in tuberculum sellae meningiomas: influence on approach, recurrence, and visual recovery. Neurosurgery 2010: 67(3 Suppl Operative): 108 -19

Case #7

Case #7

Chondrosarcoma Clinical � � � Only ~7% of all chondrosarcomas are craniocervical Sx: Headache,

Chondrosarcoma Clinical � � � Only ~7% of all chondrosarcomas are craniocervical Sx: Headache, cranial nerve palsies (CN 6 most common) Symptoms usually present long before diagnosis Imaging � � � Typically centered at the petro-ocipital fissure Chondroid matrix calcification on CT, osseous destruction in >50% MRI: T 1 iso- to hypointense, T 2 hyperintense, heterogeneously enhancing (may have whorls of enhancement) ADC values may show benefit in distinguishing from chordoma Chondrosarcoma typically has a much higher ADC value (~2000 mm 2/s compared to ~1500 mm 2/s for classic chordoma and ~900 mm 2/s for poorly differentiated chordoma) DDx: Chordoma, chondromyxoid fibroma, metastasis, plasmacytoma, meningioma Tx: Typically combined radical resection and adjuvant radiotherapy Bloch O, Parsa A. Skull base chondrosarcoma: evidence-based treatment paradigms. Neurosurgery Clinics of North America 2013: 24(1): 89 -96 Günes M, Günaldi O, Tuğcu B, et al. Intracranial chondrosarcoma: a case report and review of the literature. Minim Invasive Neurosurg 2009: 52(5 -6): 23841 Yeom K, Lober R, Mobley B, et al. Diffusion-weighted MRI: distinction of skull base chordoma from chondrosarcoma. AJNR Am J Neuroradiol 2012 Nov 1. [Epub ahead of print]

Case #8

Case #8

Case #8 (continued)

Case #8 (continued)

Chondromyxoid Fibroma Clinical � � Imaging � � 2/3 occur in long bones, 1/4

Chondromyxoid Fibroma Clinical � � Imaging � � 2/3 occur in long bones, 1/4 in flat bones, craniofacial extremely rare Slow-growing and locally destructive, no tendency to metastasize About half present in the 2 nd decade, males more common than females Most present with very slowly worsening bone pain CT: Geographic lesion with a sclerotic margin, thinning of cortex, usually expansile MRI: T 1 isointense, T 2 hyperintense with lobulations, periphery T 1 and T 2 hypointense, minimal diffuse central contrast enhancement DDx: Chondrosarcoma, aneurysmal bone cyst, fibrous dysplasia Tx: Surgical excision with curettage and bone grafting – recur in~20%, may radiate if recurrent Crocker M, Corns R, Bodi I, et al. Chondromyxoid fibroma of the skull base invading the occipitocervical junction: report of a unique case and discussion. Skull Base 2010: 20(2): 101 -4 Haygood T, Herndon M, Chitkara P, et al. Chondromyxoid fibroma involving the sphenoid sinus: case report and literature review. Radiology Case Reports 2010: 5(2)

Case #9

Case #9

Primary Pituitary Lymphoma Clinical � Incidence of primary CNS lymphoma has significantly increased over

Primary Pituitary Lymphoma Clinical � Incidence of primary CNS lymphoma has significantly increased over the last 30 years due to increased survival rates of patients with AIDS and increased rate of successful organ transplantation � Based on the 28 reported cases of primary pituitary lymphoma as of 2012 � Equal incidence in men and women Typically in the 6 th decade Presenting symptoms included endocrine dysfunction (50%), headache, visual disturbance, and other cranial neuropathies Imaging � ~2. 5% of AIDS patients will develop primary CNS lymphoma Typically hyperdense on CT, although may be isodense; may see areas of hemorrhage and/or necrosis T 1 and T 2 iso- or hypointense, may show diffusion restriction, may homogeneously enhance except for possible areas of necrosis DDx: Metastasis, sarcoid, lymphocytic hypophysitis (in our patient); toxoplasmosis, glioblastoma multiforme, metastasis Tx: Chemotherapy +/- radiation therapy +/- surgical resection Mansour, A, Qandeel M, Abdel-Razeq H, et al. MR imaging features of intracranial primary CNS lymphoma in immune competent patients. Cancer Imaging 2014: 22 -30 Rainsbury P, Mitchell-Innes A, Clifton N, et al. Primary lymphoma of the pituitary gland: an unusual cause of hemianopia in an immunocompetent patient. JRSM Short Rep 2012: 3(8): 55 -9

Case #10 (two different patients) a b

Case #10 (two different patients) a b

Metastatis (lung cancer (10 a) & GBM (10 b)) Clinical � � Only 1

Metastatis (lung cancer (10 a) & GBM (10 b)) Clinical � � Only 1 -2% of intracranial metastases are extraparenchymal or non-meningeal; typically more infiltrative Breast cancer is most common, followed by lung, kidney and colon; glioblastoma multiforme and anaplastic astrocytoma are the most common primary sites from the brain May present with diabetes insipidus, anterior pituitary insufficiency, retroorbital pain Median survival after diagnosis is 4. 1 months Imaging � � � Positive prognostic indicators include solitary pituitary metastasis, good performance status and receipt of local therapy; NOT age, gender or primary cancer type Enhancing lesion; typically small, round and infiltrating May mimic many other lesions; no pathognomonic distinguishing feature Must include in patients with a known primary and enhancing pituitary mass DDx: Macroadenoma, lymphoma, sarcoid, lymphocytic hypophysitis Tx: Radiation therapy and/or chemotherapy and/or surgical resection Akio M, Meyer F, Laws E. Symptomatic pituitary metastases. Journal of Neurosurgery 1998: 89(1): 69 -73 Lin C, Huang W, Chung F, et al. Prognostic factors in cancer patients with symptomatic pituitary metastasis: a clinical case study. Anticancer Research 2015: 35(2): 983 -7 Hermet M, Trouillier S, André M, et al. Pituitary metastasis presenting as diabetes insipidus: a report of four cases and literature review. Review of Internal Medicine 2009: 30(5): 425 -9

Case #11

Case #11

Case #11 (continued)

Case #11 (continued)

Epidermoid Clinical � � � May present with headache, cranial neuropathy, visual disturbance, hypopituitarism,

Epidermoid Clinical � � � May present with headache, cranial neuropathy, visual disturbance, hypopituitarism, diabetes insipidus Mean age of presentation 40 years, equally common in males and females Usually very slow growing, rarely degenerates into squamous cell carcinoma Rupture may lead to chemical meningitis ~10% are parasellar Imaging � � � Predominantly nonenhancing – may have minimal peripheral enhancement CT: Lobulated, hypodense mass; ~3% hyperdense due to prior hemorrhage/high proteinaceous content MRI: Cauliflower-like lobulated mass, slightly hyperintense to CSF on T 1 and T 2, diffusion restricting, insinuates cisterns and encases neurovascular structures “White” epidermoids hyperintense to grey matter on T 1 due to high triglyceride/fatty acid content “Black” epidermoids hypointense to CSF on T 1 due to solidification of cholesterol and keratin DDx: Rathke cleft cyst, craniopharyngioma, neurocysticercosis, abscess Tx: Surgical resection with tendency to recur Costa F, Fornari M, Felisati G, et al. Epidermoid cyst of the pituitary stalk: case report and review of the literature. Neurosurgery Quarterly 2013: 23(2): 108 -11 Law E, Lee R, Ng A, et al. Atypical intracranial epidermoid cysts: rare anomalies with unique radiological features. Case Reports in Radiology 2015: 4

Case #12

Case #12

Mucoepidermoid Carcinoma (mimicking craniopharyngioma) Clinical � � Imaging � � � Typically a salivary

Mucoepidermoid Carcinoma (mimicking craniopharyngioma) Clinical � � Imaging � � � Typically a salivary gland (parotid most commonly) neoplasm containing mucoussecreting cells and epidermoid cells Most common primary malignancy of the parotid gland Those with prior radiation therapy are predisposed May present with facial nerve paralysis, facial pain, enlarging facial mass Low-grade lesions are well-circumscribed, while high-grade lesions are invasive and irregular with associated lymphadenopathy Low-grade lesions tend to have cystic areas while high-grade lesions do not Hypointense T 2 areas are characteristic Heterogeneous enhancement Must evaluate for perineural spread (CN 7) DDx: Craniopharyngioma, macroadenoma or Rathke cleft cyst (in our patient), benign mixed tumor, Warthin tumor, lymphoma, adenoid cystic carcinoma Tx: Surgical resection +/- adjuvant radiation, neck dissection if high-grade Triantafillidou K, Dimitrakopoulos J, Iordanidis F, et al. Mucoepidermoid carcinoma of minor salivery glands: a clinical study of 16 cases and review of the literature. Oral Diseases 2006: 12(4): 364 -70 Van Furth W, Smyth H, Horvath E, et al. Salivery gland-like tumor of the sella. The Canadian Journal of Neurological Sciences 2007: 34(4): 478 -82

Case #13

Case #13

Lymphocytic Hypophysitis Clinical � � � Imaging � � � Inflammation of the anterior

Lymphocytic Hypophysitis Clinical � � � Imaging � � � Inflammation of the anterior pituitary gland which is idiopathic Much more common in females, typically in the 4 th decade Up to 40% misdiagnosed as adenoma Features more indicative of LH: symmetric enlargement of pituitary gland, thickened pituitary stalk (>2 mm), intact sellar floor Homogeneous enhancement Parasellar T 2 dark sign – hypointense T 2 signal around the pituitary gland cavernous sinus, NOT seen in patients with adenoma and often progresses with chronicity in patients with LH (our patient did not display this sign) DDx: Adenoma, pituitary hyperplasia, metastasis, sarcoid Tx � � Steroids and hormone replacement therapy Secondary panhypopituitarism may lead to death if untreated, however can be self-limiting Gutenberg A, Larsen J, Lupi I, et al. A radiologic score to distinguish autoimmune hypophysitis from nonsecreting pituitary adenoma preoperatively. AJNR Am J Neuroradiol 2009: 30: 1766 -72 Nakata Y, Sato N, Masumoto T, et al. Parasellar T 2 dark sign on MR imaging in patients with lymphocytic hypophysitis. AJNR Am J Neuroradiology 2010: 31: 1944 -50 Quencer R. Lymphocytic adenohypophysitis: autoimmune disorder of the pituitary gland. AJNR Am J Neuroradiol 1980: 1: 343 -5

Case #14

Case #14

Rosai Dorfman (Sinus Histiocytosis) Clinical � � � Imaging � � � Unknown etiology;

Rosai Dorfman (Sinus Histiocytosis) Clinical � � � Imaging � � � Unknown etiology; may be autoimmune or infectious Typically present in 1 st or 2 nd decade with painless neck mass(es) Massive bilateral cervical lymphadenopathy Other Sx: anosmia, facial pain, epistaxis, visual disturbance Benign entity, however morbidity increases if superimposed immune disorder present More common in males; African and West Indian heritage predominance May see involvement of dura, orbits, bone, skin and salivary glands; rarely involves airway, mediastinum Huge, enhancing lymph nodes MRI: T 1 and T 2 hypointense, enhancing and infiltrating extranodal lesions DDx: Lymphoma, meningioma, metastasis, histiocytosis Tx: Watchful waiting, steroids, surgical debulking if compression of adjacent neurovascular structures La Barge D, Salzman K, Harnsberger H, et al. Sinus histiocytosis with massive lymphadenopathy (Rosai Dorfman disease): imaging manifestations in the head and neck. American Journal of Roentgenology 2008: 191(6): W 299 -W 306 Symss N, Cugati G, Vasudevan M, et al. Intracranial Rosai Dorfman disease: report of three cases and literature review. Asian Journal of Neurosurgery 2010: 5(2): 19 -30

Case #15

Case #15

Case #15 (continued) Prior to Tx 5 days later, after steroids

Case #15 (continued) Prior to Tx 5 days later, after steroids

Paraneoplastic Syndrome Clinical � � Less than 1% of cancer patients develop paraneoplastic syndrome;

Paraneoplastic Syndrome Clinical � � Less than 1% of cancer patients develop paraneoplastic syndrome; most do not have imaging findings Most commonly due to small cell lung cancer, followed by breast cancer, gynecologic tumors and hematologic malignancies May present with seizure, altered mental status, memory loss Immune-mediated response; >50% have autoantibodies and/or specific surface antigens (as were found in this patient) Imaging � � � NMDA receptor Ab, m. Glu. R 1 Ab, voltage-gated K+ channel Ab, Hu Ab, Yo Ab, Ri Ab, CV 2 Ab Limbic encephalitis: T 2 hyperintensity throughout the mesial temporal lobes and limbic system Brainstem encephalitis: T 2 hyperintensity throughout the brainstem, as well as the cerebellar peduncles and basal ganglia Cerebellar degeneration: atrophy DDx: Metastasis/lymphoma (in our patient), herpes encephalitis, glioma Tx: Treatment of primary tumor, supportive therapy including immunosuppression and electrolyte/hormonal correction Dalmau J, Rosenfeld M. Paraneoplastic syndromes of the CNS. Lancet Neurol 2008: 7(4): 327 -40 Pelosof L, Gerber D. Paraneoplastic syndromes: an approach to diagnosis and treatment. Mayo Clinic Proceedings 2010: 85(9): 838 -54

Key Points Cavernoma � Arteriovenous Malformation � No separate pituitary gland identified Pituitary apoplexy

Key Points Cavernoma � Arteriovenous Malformation � No separate pituitary gland identified Pituitary apoplexy � CTA preferred diagnostically; MRA can demonstrate hyperintense T 1 signal with cholesterol granuloma that appears as flow-related signal Macroadenoma � “Bag of worms, ” tangle of vessels; MRI: “Honeycomb” of flow voids, enlarged feeding artery/ies and early draining vein(s) Petrous apex aneurysms � CT: Well-delineated hyperdense mass +/- calcification; MRI: popcorn appearance, hypointense hemosiderin ring on T 2, blooming on GRE, minimal/no enhancement, look for associated DVA CT hyperdensity, MRI blooming within the sella; rim enhancement suggests underlying hemorrhage; may have associated subarachnoid hemorrhage Meningioma � CT: most hyperdense, may be partially calcified, underlying bone hyperostotic; MRI: Hypoto isointense on T 1 and T 2, look for dural tail, early and prolonged enhancement (mother -in-law sign)

Key Points Chondrosarcoma � Chodromyxoid fibroma � Typically hyperdense on CT; MRI: T 1

Key Points Chondrosarcoma � Chodromyxoid fibroma � Typically hyperdense on CT; MRI: T 1 and T 2 iso- or hypointense, may restrict, homogeneous enhancement except for possible areas for necrosis Metastasis � CT: Geographic lesion with a sclerotic margin, thinning of cortex, usually expansile; MRI: T 1 isointense, T 2 hyperintense with lobulations, minimal enhancement Pituitary lymphoma � Typically centered at the petro-ocipital fissure, chondroid matrix calcification on CT; MRI may demonstrate whorls of enhancement, ADC values may show benefit in distinguishing from chordoma Must include in patients with a known primary and enhancing pituitary mass Epidermoid � Nonenhancing, cauliflower-like lobulated mass, slightly hyperintense to CSF on T 1 and T 2, diffusion restricting, insinuates cisterns and encases neurovascular structures “White” epidermoids hyperintense to grey matter on T 1 due to high triglyceride/fatty acid content “Black” epidermoids hypointense to CSF on T 1 due to solidification of cholesterol and keratin

Key Points Mucoepidermoid carcinoma � Lymphocytic Hypophysitis � Symmetric enlargement of pituitary gland, thickened

Key Points Mucoepidermoid carcinoma � Lymphocytic Hypophysitis � Symmetric enlargement of pituitary gland, thickened pituitary stalk (>2 mm); homogeneous enhancement; parasellar T 2 dark sign – low T 2 signal around the pituitary gland/cavernous sinus Rosai Dorfman � Hypointense T 2 areas are characteristic, must evaluate for perineural spread (CN 7) Huge, enhancing lymph nodes; MRI: T 1 and T 2 hypointense, enhancing and infiltrating extranodal lesions Paraneoplastic syndrome � Limbic/brainstem encephalitis: T 2 hyperintensity; cerebellar degeneration with atrophy; serum markers necessary in atypical cases

Summary Many less commonly encountered pathologies of the sellar and suprasellar spaces may mimic

Summary Many less commonly encountered pathologies of the sellar and suprasellar spaces may mimic those lesions which present more commonly in practice. In contrast, typical lesions of the sellar and suprasellar spaces may have atypical imaging characteristics, altering our differentials. Here, we review a set of cases which challenge both our knowledge of sellar and suprasellar lesions, as well as our eyes. Attanasio R, Cozzi R, Lasio G, et al. Diagnositc evaluation of the lesions of the sellar and parasellar region. Explicative Cases of Controversial Issues in Neurosurgery. Rijeka: Signorelli; 2012: 97 -166 Shah L, Phillips C. Imaging sellar and suprasellar pathology. Applied Radiology 2009 Apr: 9 -21 Patel Z, Gupta S. Imaging in common anterior and sellar/parasellar skull base lesions. Otorhinolaryngology Clinics 2011: 3(3): 135 -50