192 lines
16 KiB
Markdown
192 lines
16 KiB
Markdown
---
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title: "Sella/Pituitary Normal Variants"
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docid: "ad280a2d-6df3-4f2d-a195-623332ca7634"
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authors:
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- key: "318f80ab-6abb-4067-a809-2ebdaa5a30c9"
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value: "Kalen Riley, MD, MBA"
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- key: "5cff4116-3654-4b3a-bb75-5ebe0b8c9850"
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value: "Anne G. Osborn, MD, FACR"
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- key: "8d5254e9-8dda-478b-8f08-bdee97a32c79"
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value: "Karen L. Salzman, MD, FACR"
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breadcrumbs:
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-
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name: "Brain"
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slug: "brain"
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treeNodeId: "6d8829f1-14d7-45af-8675-255189aa526a"
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-
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name: "Differential Diagnosis"
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slug: "differential-diagnosis"
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treeNodeId: "a7fdd139-664e-4bb8-8d18-400e4733ff60"
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-
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name: "Sella/Juxtasellar, Pineal Region"
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slug: "sellajuxtasellar-pineal-region"
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treeNodeId: "5e38b9c1-3137-47e3-aa83-1fc82cb4099a"
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-
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name: "Anatomically Based Differentials"
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slug: "anatomically-based-differentials"
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treeNodeId: "7a51b2ca-8fee-4c16-aff3-b7189f68ea60"
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-
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name: "Sella/Pituitary Normal Variants"
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slug: "sellapituitary-normal-variants"
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treeNodeId: null
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category: "Brain"
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documentVersionId: "6f83a5f1-4d99-417f-bafe-faba264f4b2e"
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imageCount: 16
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lastUpdated: "01/26/23"
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pageDescription: "Sella/Pituitary Normal Variants"
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pageKeywords: "Brain, Differential Diagnosis, Sella/Juxtasellar, Pineal Region, Anatomically Based Differentials, Sella/Pituitary Normal Variants"
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pageTitle: "Sella/Pituitary Normal Variants | STATdx"
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enhancedTitle: "Sella/Pituitary Normal Variants"
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type: "DDX"
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references: true
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breadcrumbs:
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- "Brain"
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- "Differential Diagnosis"
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- "Sella/Juxtasellar, Pineal Region"
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- "Anatomically Based Differentials"
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- "Sella/Pituitary Normal Variants"
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---
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# ESSENTIAL INFORMATION
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- ## Key Differential Diagnosis Issues
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- Prior to evaluating sella/pituitary, essential to know patient age, sex
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- Maximum height varies with age, sex
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- Children: 6 mm
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- Males, postmenopausal females: 8 mm
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- Young females: 10 mm; up to 12 mm may be normal
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- Pregnant/lactating females: 12 mm; up to 14 mm may be normal
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- ## Helpful Clues for Common Diagnoses
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- **Pituitary Hyperplasia (Physiologic)**
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- Enlarged pituitary gland
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- 10-15 mm, convex upward margin
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- Enhances strongly, uniformly
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- Indistinguishable from pathologic hyperplasia from end-organ failure or neuroendocrine tumor
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- May be indistinguishable from macroadenoma, lymphocytic hypophysitis
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- Beware: Macroadenoma-appearing pituitary in young male patients may be physiologic hyperplasia, not tumor
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- **Pituitary "Incidentaloma"**
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- Pituitary lesions in 15-20% of asymptomatic patients
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- Cystic changes common, may be transient
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- May represent incidental nonfunctional microadenoma, Rathke cleft cyst, or pars intermedia cyst
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- **"Empty" Sella**
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- Rarely (if ever) truly empty, more often partially empty
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- Intrasellar CSF, pituitary gland flattened against sellar floor
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- Primary "empty" sella
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- Considered normal variant
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- Usually asymptomatic, incidental finding
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- 5-10% prevalence
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- Peak age: 40-49 years; 4:1 female predominance
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- Secondary "empty" sella
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- Surgery, radiation, bromocriptine therapy
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- Sheehan syndrome (postpartum pituitary necrosis)
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- Commonly associated with idiopathic intracranial hypertension
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- ## Helpful Clues for Less Common Diagnoses
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- **"Bright" Pituitary Gland**
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- Neonate: Adenohypophysis large, hyperintense on T1 MR
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- Size, signal ↓ during first 6 weeks
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- **Absent Posterior Pituitary "Bright Spot"**
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- Neurohypophysis normally has T1 shortening
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- Found in up to 20% of normal patients
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- Commonly absent in central diabetes insipidus
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- Consider Langerhans cell histiocytosis, germinoma
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- May be associated with pituitary hypoplasia, look for ectopic posterior bright spot
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- **Small Sella Turcica**
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- Small or shallow bony sella can be normal
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- Causes pituitary gland to protrude upward
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## References
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# Selected References
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1. [Lubomirsky B et al: Sellar, suprasellar, and parasellar masses: imaging features and neurosurgical approaches. Neuroradiol J. 35(3):269-23, 2022](http://www.ncbi.nlm.nih.gov/pubmed/?term=34856828%5Bpmid%5D)
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1. [Shih RY et al: Primary tumors of the pituitary gland: radiologic-pathologic correlation. Radiographics. 41(7):2029-46, 2021](http://www.ncbi.nlm.nih.gov/pubmed/?term=34597177%5Bpmid%5D)
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1. [Go JL et al: Imaging of the sella and parasellar region. Radiol Clin North Am. 55(1):83-101, 2017](http://www.ncbi.nlm.nih.gov/pubmed/?term=27890190%5Bpmid%5D)
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1. [Seeburg DP et al: Imaging of the sella and parasellar region in the pediatric population. Neuroimaging Clin N Am. 27(1):99-121, 2017](http://www.ncbi.nlm.nih.gov/pubmed/?term=27889026%5Bpmid%5D)
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1. [Vasilev V et al: Management of endocrine disease: pituitary 'incidentaloma': neuroradiological assessment and differential diagnosis. Eur J Endocrinol. 175(4):R171-84, 2016](http://www.ncbi.nlm.nih.gov/pubmed/?term=27068689%5Bpmid%5D)
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1. [Sioshansi PC et al: considering the ectopic pituitary gland in evaluation of the nasopharyngeal mass. JAMA Otolaryngol Head Neck Surg. 141(7):649-53, 2015](http://www.ncbi.nlm.nih.gov/pubmed/?term=25974707%5Bpmid%5D)
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1. [Ranganathan S et al: Magnetic resonance imaging finding of empty sella in obesity related idiopathic intracranial hypertension is associated with enlarged sella turcica. Neuroradiology. 55(8):955-61, 2013](http://www.ncbi.nlm.nih.gov/pubmed/?term=23708942%5Bpmid%5D)
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1. [Hess CP et al: Imaging the pituitary and parasellar region. Neurosurg Clin N Am. 23(4):529-42, 2012](http://www.ncbi.nlm.nih.gov/pubmed/?term=23040741%5Bpmid%5D)
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## Images
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### Selected Images
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**Pituitary Hyperplasia (Physiologic)**
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*Sagittal T1 MR in a young, postpartum, lactating female shows an upwardly bulging pituitary gland <img src='img/arrows/CO.png'/> related to physiologic pituitary hyperplasia with the gland measuring almost 12 mm in height. Physiologic hyperplasia is most common in young, menstruating females and postpartum/lactating women.*
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**Pituitary Hyperplasia (Physiologic)**
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*Sagittal T1 MR in a young, postpartum, lactating female shows an upwardly bulging pituitary gland <img src='img/arrows/CO.png'/> related to physiologic pituitary hyperplasia with the gland measuring almost 12 mm in height. Physiologic hyperplasia is most common in young, menstruating females and postpartum/lactating women.*
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**Pituitary "Incidentaloma"**
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*Coronal T2 MR in an asymptomatic adult shows a hyperintense pituitary cyst <img src='img/arrows/CS.png'/>, possibly a small Rathke cleft cyst or nonfunctioning cystic adenoma. Such findings are common at both imaging (15-20% of cases) and autopsy.*
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**Pituitary "Incidentaloma"**
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*Coronal T1 C+ MR shows a pituitary "incidentaloma" as a small, nonenhancing lesion <img src='img/arrows/CO.png'/> in the pituitary gland in an asymptomatic patient being evaluated for metastatic disease. This cyst remained stable for many years. Findings are likely related to a nonfunctioning pituitary microadenoma and requires no therapy.*
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**"Empty" Sella**
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*Sagittal T1 MR shows marked flattening of the pituitary gland against the floor of the sella <img src='img/arrows/CO.png'/> with associated enlargement of the suprasellar cistern CSF space <img src='img/arrows/CS.png'/> in this young adult.*
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**"Bright" Pituitary Gland**
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*Sagittal T1 MR in a newborn shows a large, hyperintense adenohypophysis <img src='img/arrows/CS.png'/>, a normal finding.*
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**Absent Posterior Pituitary "Bright Spot"**
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*Coronal T1 MR shows an ectopic posterior pituitary bright spot. The posterior pituitary gland is located at the median eminence of the hypothalamus <img src='img/arrows/WO.png'/> in between the normal optic tracts <img src='img/arrows/CC.png'/>. No normal infundibulum is seen in this patient. The median eminence is the typical location for an ectopic posterior pituitary gland. These patients often have short stature and midline CNS anomalies.*
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**Small Sella Turcica**
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*Sagittal T1 C+ MR shows a small, shallow sella turcica <img src='img/arrows/WC.png'/>. This causes the normal-sized pituitary gland <img src='img/arrows/CS.png'/> to protrude superiorly, mimicking a macroadenoma. The overall height of the pituitary gland was normal at 10 mm in this young patient.*
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**Paramedian ("Kissing") Internal Carotid Arteries**
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*Axial T1 MR shows the flow voids of both cavernous internal carotid arteries, which curve much more medially than usual <img src='img/arrows/CS.png'/>. "Kissing carotids" are normal variants. The pituitary gland often appears enlarged in these patients given the decreased transverse dimension of the pituitary.*
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### Additional Images
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**Pituitary Hyperplasia (Physiologic)**
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*Coronal T1 C+ MR in a young, postpartum, lactating female shows an upwardly bulging pituitary gland <img src='img/arrows/CS.png'/>. Physiologic hyperplasia with gland measured almost 12 mm in height.*
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**Pituitary Hyperplasia (Physiologic)**
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*Sagittal T1 C+ MR shows physiologic enlargement of the pituitary gland <img src='img/arrows/WS.png'/> in a young, asymptomatic patient.*
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**Pituitary Hyperplasia (Physiologic)**
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*Coronal T1 C+ MR in a young, menstruating female shows slight, inhomogeneous enhancement <img src='img/arrows/WS.png'/> in this gland with mild upward bulging <img src='img/arrows/CC.png'/>. No frank intrapituitary cysts are identified; the mild inhomogeneity in enhancement is normal.*
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**Pituitary "Incidentaloma"**
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*Sagittal T1 C+ MR in an asymptomatic adult shows a nonenhancing pituitary cyst <img src='img/arrows/CS.png'/>, possibly a small Rathke cleft cyst. Such findings are common at both imaging (15-20% of cases) and autopsy.*
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**Pituitary "Incidentaloma"**
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*Coronal CECT in an asymptomatic patient shows a nonenhancing, hypodense focus <img src='img/arrows/CS.png'/> in the pituitary gland. This lesion is likely related to a nonneoplastic pituitary cyst or a nonfunctioning microadenoma.*
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**"Empty" Sella**
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*Sagittal T1 MR shows the expected findings of a secondary empty sella after transsphenoidal hypophysectomy. The enlarged sella is mostly filled with CSF <img src='img/arrows/WS.png'/>.*
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**Small Sella Turcica**
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*Sagittal T1 MR shows a small, shallow sella <img src='img/arrows/WS.png'/> and pituitary <img src='img/arrows/WO.png'/> in a patient with Kallmann syndrome with hypopituitarism. Small sella also occurs as a normal variant, indistinguishable on imaging alone.*
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**Small Sella Turcica**
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*Coronal T1 C+ MR shows a flat, shallow sella turcica <img src='img/arrows/WO.png'/> causing upward bulging of the pituitary gland <img src='img/arrows/WS.png'/>. Gland height measured 9 mm, normal in this young woman.*
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