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---
title: "Hypothalamus Lesion"
docid: "0fc29bff-9f20-4e19-a436-04c7791e3972"
authors:
- key: "318f80ab-6abb-4067-a809-2ebdaa5a30c9"
value: "Kalen Riley, MD, MBA"
- key: "f184750a-90b4-47a7-907b-23b05d70357a"
value: "Chang Yueh Ho, MD"
- key: "5cff4116-3654-4b3a-bb75-5ebe0b8c9850"
value: "Anne G. Osborn, MD, FACR"
breadcrumbs:
-
name: "Brain"
slug: "brain"
treeNodeId: "6d8829f1-14d7-45af-8675-255189aa526a"
-
name: "Differential Diagnosis"
slug: "differential-diagnosis"
treeNodeId: "a7fdd139-664e-4bb8-8d18-400e4733ff60"
-
name: "Sella/Juxtasellar, Pineal Region"
slug: "sellajuxtasellar-pineal-region"
treeNodeId: "5e38b9c1-3137-47e3-aa83-1fc82cb4099a"
-
name: "Anatomically Based Differentials"
slug: "anatomically-based-differentials"
treeNodeId: "7a51b2ca-8fee-4c16-aff3-b7189f68ea60"
-
name: "Hypothalamus Lesion"
slug: "hypothalamus-lesion"
treeNodeId: null
category: "Brain"
documentVersionId: "16e05176-4cdf-4ac0-a619-ad1f294263ce"
imageCount: 38
lastUpdated: "03/15/23"
pageDescription: "Hypothalamus Lesion"
pageKeywords: "Brain, Differential Diagnosis, Sella/Juxtasellar, Pineal Region, Anatomically Based Differentials, Hypothalamus Lesion"
pageTitle: "Hypothalamus Lesion | STATdx"
enhancedTitle: "Hypothalamus Lesion"
type: "DDX"
references: true
breadcrumbs:
- "Brain"
- "Differential Diagnosis"
- "Sella/Juxtasellar, Pineal Region"
- "Anatomically Based Differentials"
- "Hypothalamus Lesion"
---
# ESSENTIAL INFORMATION
- ## Key Differential Diagnosis Issues
- Anatomic essentials
- Hypothalamus lies below level of anterior, posterior commissures
- Inferior hypothalamus formed by
- Anterior recesses of 3rd ventricle
- Tuber cinereum
- Mammillary bodies
- Infundibular stalk
- ## Helpful Clues for Common Diagnoses
- **Astrocytoma**
- Most common primary neoplasm arising from hypothalamic-optic chiasm structures
- Usually low grade (pilocytic astrocytoma WHO grade1)
- Age < 5 years
- Endocrine dysfunction in 20%
- Look for evidence for neurofibromatosis type 1
- 20-50% of patients with pilocytic astrocytoma
- **Craniopharyngioma**
- **Adamantinomatous**
- Most common suprasellar mass in children
- Occurs anywhere from intrasellar to stalk to anteroinferior 3rd ventricle
- 90% calcify, 90% have multiple cysts (mixed signal intensity), 90% calcify
- **Papillary**
- Occurs along hypothalamic-pituitary axis, often infundibulum and tuber cinereum of 3rd ventricle floor
- Often solid, may be cystic and solid
- ## Helpful Clues for Less Common Diagnoses
- **Germ Cell Tumor**
- Can be primary in hypothalamus/stalk
- M = F (vs. male predominance in pineal gland)
- 10% "double" midline lesions (pineal and hypothalamus)
- Diabetes insipidus, diencephalic syndrome, precocious puberty common
- Thick, enhancing stalk, 3rd floor, absent posterior pituitary bright spot
- Pure germinoma demonstrates more homogeneous enhancement with rapid response to chemotherapy
- Intermediate and mixed germ cell tumors are more heterogeneous without rapid treatment response
- Mature teratomas may have calcification, fat, and other differentiated cell types (hair, teeth, etc.)
- **Neurosarcoid**
- Adult with stalk, meningeal lesions
- Other infectious/inflammatory lesions that can mimic sarcoid
- Granulomatosis with polyangiitis (GPA)
- Tuberculosis, syphilis
- **Langerhans Cell Histiocytosis**
- Stalk/hypothalamus lesion in child
- **Lipoma**
- Lipoma: Sessile T1-hyperintense lesion on subpial surface of hypothalamus
- Osteolipoma: Rare; fat-density/signal intensity and calcification
- **Lymphocytic****H****y****pophysitis**
- Peripartum female common; other etiologies include granulomatous, Ig-G4-related, drug-related, etc.
- Can mimic macroadenoma
- **Metastases**
- **Hypothalamic-pituitary axis metastases**
- 1-25% of systemic cancers at autopsy
- Less common at imaging
- Breast, lung most common primary tumors
- **Lymphoma**
- Pituitary/stalk/hypothalamus uncommon site
- Can be primary or metastatic
- **Tuber****C****inereum Hamartoma**
- Children with gelastic seizures, males with isosexual precocious puberty
- Can be pedunculated or sessile
- Density/signal intensity typically isointense with cortex
- No calcification, enhancement
- Sessile lesion may be difficult to distinguish from hypothalamic astrocytoma (no change on follow-up)
- **Ectopic Posterior Pituitary**
- Failure of neurohypophysis to migrate from hypothalamus
- T1-hyperintense lesion anywhere from hypothalamus through stalk
- Associated with septo-optic dysplasia
- **Dermoid Cyst**
- Inclusion of surface ectoderm with neural tube closure
- Includes fat: Fat-suppression MR techniques and negative HU on CT
- May rupture with leptomeningeal fat deposits
- Can cause chemical meningitis
- No fat with decreased diffusion = epidermoid
- **Rathke Cleft Cyst**
- Like craniopharyngioma, arises from squamous cell rests migrating through craniopharyngeal duct, forming sellar/suprasellar mass
- Nonenhancing cysts with central protein: Variable T1 hyperintensity and T2 hypointensity
- When large, can involve hypothalamus
- ## Helpful Clues for Rare Diagnoses
- **Other****G****liomas**
- **Chordoid g****lioma**
- Floor of 3rd ventricle
- Hyperintense with strong, uniform enhancement
- **Pilomyxoid a****strocytoma**
- Infant/young child
- H-shaped tumor of hypothalamus; extension into medial temporal lobes common
- Often large, bulky ± hemorrhage (rare in pilocytic astrocytoma)
- WHO grade1, subtype of pilocytic astrocytoma
- **Pituicytoma**
- Stalk, posterior pituitary lobe
- Low-grade astrocytoma
- Enhances strongly, uniformly
- **Ganglioglioma**
- Very rare in hypothalamus/chiasm
- Young adult (mean age = 20 years)
- **Wernicke Encephalopathy**
- Acute: Abnormal hyperintensity/enhancement of mammillary bodies, inferolateral walls of 3rd ventricle, periaqueductal gray matter
- Chronic: Mammillary atrophy
- Note: Occurs in both alcoholics, nonalcoholics (e.g., longstanding parenteral nutrition, hyperemesis, bariatric surgery)
- **Demyelinating****D****isease**
- Optic chiasm involvement > > hypothalamus
- Enhancing, slightly enlarged optic nerves/chiasm seen with both multiple sclerosis, ADEM
## References
# Selected References
1. [Pascual JM et al: Duct-like recess in the infundibular portion of third ventricle craniopharyngiomas: an MRI sign identifying the papillary type. AJNR Am J Neuroradiol. 43(9):1333-40, 2022](http://www.ncbi.nlm.nih.gov/pubmed/?term=35953277%5Bpmid%5D)
1. [Tierney TS et al: Initial experience with magnetic resonance-guided focused ultrasound stereotactic surgery for central brain lesions in young adults. J Neurosurg. 1-8, 2022](http://www.ncbi.nlm.nih.gov/pubmed/?term=35171812%5Bpmid%5D)
1. [Shields R et al: Magnetic resonance imaging of sellar and juxtasellar abnormalities in the paediatric population: an imaging review. Insights Imaging. 6(2):241-60, 2015](http://www.ncbi.nlm.nih.gov/pubmed/?term=25794595%5Bpmid%5D)
1. [Zhang Y et al: Hypothalamus syndrome in opticospinal multiple sclerosis. AJNR Am J Neuroradiol. 32(8):E153-5, 2011](http://www.ncbi.nlm.nih.gov/pubmed/?term=21051517%5Bpmid%5D)
1. [Hamilton BE et al: Anatomic and pathologic spectrum of pituitary infundibulum lesions. AJR Am J Roentgenol. 188(3):W223-32, 2007](http://www.ncbi.nlm.nih.gov/pubmed/?term=17312027%5Bpmid%5D)
1. [Saleem SN et al: Lesions of the hypothalamus: MR imaging diagnostic features. Radiographics. 27(4):1087-108, 2007](http://www.ncbi.nlm.nih.gov/pubmed/?term=17620469%5Bpmid%5D)
## Images
### Selected Images
![Axial T2 MR shows a T2-hyperintense mass <img src='img/arrows/CS.png'/> centered in the hypothalamus and optic chiasm with associated cysts <img src='img/arrows/CO.png'/>. This was a pilocytic astrocytoma at resection. Low-grade astrocytomas typically have T2-hyperintense solid components.](images/app.statdx.com_image_thumbnail_05e9ecd8-142c-4ed8-9f8f-0848cc8337d9_annotated_true_size_900_quality_90_2a281ef1.jpg)
**Astrocytoma**
*Axial T2 MR shows a T2-hyperintense mass <img src='img/arrows/CS.png'/> centered in the hypothalamus and optic chiasm with associated cysts <img src='img/arrows/CO.png'/>. This was a pilocytic astrocytoma at resection. Low-grade astrocytomas typically have T2-hyperintense solid components.*
![Axial T2 MR shows a T2-hyperintense mass <img src='img/arrows/CS.png'/> centered in the hypothalamus and optic chiasm with associated cysts <img src='img/arrows/CO.png'/>. This was a pilocytic astrocytoma at resection. Low-grade astrocytomas typically have T2-hyperintense solid components.](images/app.statdx.com_image_thumbnail_05e9ecd8-142c-4ed8-9f8f-0848cc8337d9_size_174_quality_85_4c7b12ad.jpg)
**Astrocytoma**
*Axial T2 MR shows a T2-hyperintense mass <img src='img/arrows/CS.png'/> centered in the hypothalamus and optic chiasm with associated cysts <img src='img/arrows/CO.png'/>. This was a pilocytic astrocytoma at resection. Low-grade astrocytomas typically have T2-hyperintense solid components.*
![Sagittal T1 C+ MR shows a lobular, intensely enhancing suprasellar mass involving the hypothalamus and optic chiasm <img src='img/arrows/CO.png'/>. A nonenhancing cyst <img src='img/arrows/CS.png'/> is seen anteriorly to the mass. This was a pilocytic astrocytoma, WHO grade 1 at resection.](images/app.statdx.com_image_thumbnail_d7cd41c7-9f98-42c1-a9c7-cef3f4d8da82_annotated_true_size_900_quality_90_54be4a42.jpg)
**Astrocytoma**
*Sagittal T1 C+ MR shows a lobular, intensely enhancing suprasellar mass involving the hypothalamus and optic chiasm <img src='img/arrows/CO.png'/>. A nonenhancing cyst <img src='img/arrows/CS.png'/> is seen anteriorly to the mass. This was a pilocytic astrocytoma, WHO grade 1 at resection.*
![Sagittal NECT shows a cystic mass <img src='img/arrows/CS.png'/> with a solid and densely calcified component <img src='img/arrows/CO.png'/> in the sella of this child. The mass involves the entire hypothalamic pituitary axis and extends into the 3rd ventricle.](images/app.statdx.com_image_thumbnail_cda7e009-9633-45b9-b5fe-5d02acb1e12b_annotated_true_size_900_quality_90_86b09026.jpg)
**Craniopharyngioma**
*Sagittal NECT shows a cystic mass <img src='img/arrows/CS.png'/> with a solid and densely calcified component <img src='img/arrows/CO.png'/> in the sella of this child. The mass involves the entire hypothalamic pituitary axis and extends into the 3rd ventricle.*
![Sagittal T1 C+ MR shows rim enhancement <img src='img/arrows/CS.png'/> of the cystic component of the suprasellar mass with heterogeneous enhancement of the solid component in the sella <img src='img/arrows/CO.png'/>. The solid portion showed dense calcification on a prior CT scan, consistent with adamantinomatous craniopharyngioma.](images/app.statdx.com_image_thumbnail_4738c212-17e9-43a9-9c2f-4d054f22c562_annotated_true_size_900_quality_90_336b2fef.jpg)
**Craniopharyngioma**
*Sagittal T1 C+ MR shows rim enhancement <img src='img/arrows/CS.png'/> of the cystic component of the suprasellar mass with heterogeneous enhancement of the solid component in the sella <img src='img/arrows/CO.png'/>. The solid portion showed dense calcification on a prior CT scan, consistent with adamantinomatous craniopharyngioma.*
![Coronal T1 C+ FS MR shows a lobular, enhancing mass <img src='img/arrows/CS.png'/> centered in the hypothalamus and pituitary stalk. This was a germinoma at surgery. Suprasellar and pineal midline locations are the most common location for intracranial germinomas.](images/app.statdx.com_image_thumbnail_c41ad38b-6ffb-4793-b485-f2d62b6a8c49_annotated_true_size_900_quality_90_0e182843.jpg)
**Germ Cell Tumor**
*Coronal T1 C+ FS MR shows a lobular, enhancing mass <img src='img/arrows/CS.png'/> centered in the hypothalamus and pituitary stalk. This was a germinoma at surgery. Suprasellar and pineal midline locations are the most common location for intracranial germinomas.*
![Sagittal T1 C+ FS MR shows heterogeneous pial and parenchymal enhancement of the hypothalamus, anterior 3rd ventricle, lateral ventricles, and rostrum of the corpus callosum <img src='img/arrows/CS.png'/>. In addition, there is leptomeningeal enhancement <img src='img/arrows/CO.png'/> seen in the midline sulci.](73261ea0-fb3d-4e63-abd0-f385fc9be2f8)
**Neurosarcoid**
*Sagittal T1 C+ FS MR shows heterogeneous pial and parenchymal enhancement of the hypothalamus, anterior 3rd ventricle, lateral ventricles, and rostrum of the corpus callosum <img src='img/arrows/CS.png'/>. In addition, there is leptomeningeal enhancement <img src='img/arrows/CO.png'/> seen in the midline sulci.*
![Sagittal T1 C+ FS MR shows a heterogeneously enhancing hypothalamic mass <img src='img/arrows/CS.png'/> in a child with known Langerhans cell histiocytosis (LCH). This significantly decreased in size after treatment. An absent posterior pituitary &quot;bright spot&quot; is common in LCH.](8fff7426-bd04-4330-8077-6a3bd0c1bd25)
**Langerhans Cell Histiocytosis**
*Sagittal T1 C+ FS MR shows a heterogeneously enhancing hypothalamic mass <img src='img/arrows/CS.png'/> in a child with known Langerhans cell histiocytosis (LCH). This significantly decreased in size after treatment. An absent posterior pituitary &quot;bright spot&quot; is common in LCH.*
![Sagittal T1 MR shows an intrinsically T1- hyperintense hypothalamic/suprasellar mass, consistent with lipoma <img src='img/arrows/CS.png'/>. Fat-saturated images (not shown) demonstrated complete suppression of hyperintense signal.](a39529ba-6f3f-4b50-a4d9-4ab6bf1aac42)
**Lipoma**
*Sagittal T1 MR shows an intrinsically T1- hyperintense hypothalamic/suprasellar mass, consistent with lipoma <img src='img/arrows/CS.png'/>. Fat-saturated images (not shown) demonstrated complete suppression of hyperintense signal.*
![Sagittal T1 C+ FS MR in a postpartum female with lymphocytic hypophysitis shows an enhancing, heterogeneous lesion involving the pituitary infundibulum and anterior pituitary gland <img src='img/arrows/CS.png'/>. There is reactive thickening of adjacent meninges <img src='img/arrows/CO.png'/>.](efdecbe2-7e09-4ab8-9d5b-4a6a8b3a0b8d)
**Lymphocytic Hypophysitis**
*Sagittal T1 C+ FS MR in a postpartum female with lymphocytic hypophysitis shows an enhancing, heterogeneous lesion involving the pituitary infundibulum and anterior pituitary gland <img src='img/arrows/CS.png'/>. There is reactive thickening of adjacent meninges <img src='img/arrows/CO.png'/>.*
![Sagittal T1 C+ FS MR shows a newly developed, avidly enhancing hypothalamic mass <img src='img/arrows/CS.png'/> in a patient with known metastatic genitourinary malignancy. Lung and breast cancer are the most common primary tumors to metastasize to the hypothalamic region.](de757b75-f35f-424a-adf6-7854bfc8c485)
**Metastases**
*Sagittal T1 C+ FS MR shows a newly developed, avidly enhancing hypothalamic mass <img src='img/arrows/CS.png'/> in a patient with known metastatic genitourinary malignancy. Lung and breast cancer are the most common primary tumors to metastasize to the hypothalamic region.*
![Sagittal T1 C+ MR shows a nonenhancing mass arising from the tuber cinereum <img src='img/arrows/CS.png'/>, which follows brain parenchyma in intensity. In a child with gelastic seizures, this is a hypothalamic hamartoma.](c5a4e3c6-3d82-457f-bac5-e9a67be49ed8)
**Tuber Cinereum Hamartoma**
*Sagittal T1 C+ MR shows a nonenhancing mass arising from the tuber cinereum <img src='img/arrows/CS.png'/>, which follows brain parenchyma in intensity. In a child with gelastic seizures, this is a hypothalamic hamartoma.*
![Coronal T1 MR shows a hyperintense lesion in the hypothalamus in this infant with hormonal abnormality. This is consistent with ectopic posterior pituitary <img src='img/arrows/CS.png'/>. Note the intact septum pellucidum <img src='img/arrows/CO.png'/>, which does not suggest septo-optic dysplasia. Ectopic posterior pituitary is often associated with septo-optic dysplasia.](d37cf870-62ea-44d4-a539-f786408a3528)
**Ectopic Posterior Pituitary**
*Coronal T1 MR shows a hyperintense lesion in the hypothalamus in this infant with hormonal abnormality. This is consistent with ectopic posterior pituitary <img src='img/arrows/CS.png'/>. Note the intact septum pellucidum <img src='img/arrows/CO.png'/>, which does not suggest septo-optic dysplasia. Ectopic posterior pituitary is often associated with septo-optic dysplasia.*
![Sagittal T1 MR shows a cystic lesion with T1 hyperintensity involving the sella and stalk <img src='img/arrows/CS.png'/>. This demonstrates loss of signal on fat saturation technique (not shown) and is consistent with a dermoid cyst confirmed at surgery. No leptomeningeal fatty deposits were seen to suggest rupture.](6669894b-3e81-46d8-8a51-9d5181bb67bd)
**Dermoid Cyst**
*Sagittal T1 MR shows a cystic lesion with T1 hyperintensity involving the sella and stalk <img src='img/arrows/CS.png'/>. This demonstrates loss of signal on fat saturation technique (not shown) and is consistent with a dermoid cyst confirmed at surgery. No leptomeningeal fatty deposits were seen to suggest rupture.*
![Axial T2 FS MR shows a unilocular cyst involving the stalk and hypothalamus with a fluid-fluid level <img src='img/arrows/CS.png'/>. This was a Rathke cleft cyst at surgery. Fluid levels in a Rathke cleft cyst may be from layering protein or recent hemorrhage.](8bc21a58-fb5a-4c18-8b54-41bb869d1869)
**Rathke Cleft Cyst**
*Axial T2 FS MR shows a unilocular cyst involving the stalk and hypothalamus with a fluid-fluid level <img src='img/arrows/CS.png'/>. This was a Rathke cleft cyst at surgery. Fluid levels in a Rathke cleft cyst may be from layering protein or recent hemorrhage.*
![Axial T1 C+ MR shows a heterogeneous, enhancing mass involving the chiasm, hypothalamus, and left optic tract <img src='img/arrows/CS.png'/>. A cyst <img src='img/arrows/CO.png'/> is seen associated with the mass with effacement of the left temporal horn <img src='img/arrows/CC.png'/>. This was a ganglioglioma at resection.](2fd549e0-7f95-4a18-b982-f1ce27f76245)
**Ganglioglioma**
*Axial T1 C+ MR shows a heterogeneous, enhancing mass involving the chiasm, hypothalamus, and left optic tract <img src='img/arrows/CS.png'/>. A cyst <img src='img/arrows/CO.png'/> is seen associated with the mass with effacement of the left temporal horn <img src='img/arrows/CC.png'/>. This was a ganglioglioma at resection.*
![Sagittal FLAIR MR shows T2 hyperintensity and swelling involving the ependymal margins at the foramen of Monro <img src='img/arrows/CS.png'/> and hypothalamus/optic chiasm <img src='img/arrows/CO.png'/>. The patient later developed myelitis and was diagnosed with neuromyelitis optica.](3c6d205d-cc2b-474b-94de-66fae6ea11d8)
**Demyelinating Disease**
*Sagittal FLAIR MR shows T2 hyperintensity and swelling involving the ependymal margins at the foramen of Monro <img src='img/arrows/CS.png'/> and hypothalamus/optic chiasm <img src='img/arrows/CO.png'/>. The patient later developed myelitis and was diagnosed with neuromyelitis optica.*
### Additional Images
![Sagittal T1 C+ MR shows a newly developed enhancing solid and cystic suprasellar and hypothalamic mass <img src='img/arrows/CS.png'/> in a patient with known metastatic lung cancer.](a966af20-cc22-4d8e-bb15-40c37442d2fe)
**Metastases**
*Sagittal T1 C+ MR shows a newly developed enhancing solid and cystic suprasellar and hypothalamic mass <img src='img/arrows/CS.png'/> in a patient with known metastatic lung cancer.*
![Sagittal T1 C+ MR shows an enhancing, thickened infundibular stalk <img src='img/arrows/WS.png'/> in patient with known systemic cancer. This was the only intracranial lesion identified.](94f50504-c494-4027-aa5e-bf37a9da78b2)
**Metastases**
*Sagittal T1 C+ MR shows an enhancing, thickened infundibular stalk <img src='img/arrows/WS.png'/> in patient with known systemic cancer. This was the only intracranial lesion identified.*
![Sagittal T1 MR shows a lobulated, hyperintense lesion <img src='img/arrows/WS.png'/> extending posteriorly along the hypothalamus from the tuber cinereum to the mammillary bodies.](950bdd82-0eda-4000-bd0c-74a41b4a1e36)
**Lipoma**
*Sagittal T1 MR shows a lobulated, hyperintense lesion <img src='img/arrows/WS.png'/> extending posteriorly along the hypothalamus from the tuber cinereum to the mammillary bodies.*
![Sagittal T1 C+ MR shows small pituitary fossa <img src='img/arrows/BO.png'/> with absent posterior pituitary &quot;bright spot&quot; and bulbous enlargement of infundibulum <img src='img/arrows/WC.png'/> at its origin from the hypothalamus.](695b77be-38c6-4643-bd02-b2cc74047d87)
**Ectopic Posterior Pituitary**
*Sagittal T1 C+ MR shows small pituitary fossa <img src='img/arrows/BO.png'/> with absent posterior pituitary &quot;bright spot&quot; and bulbous enlargement of infundibulum <img src='img/arrows/WC.png'/> at its origin from the hypothalamus.*
![Axial FLAIR MR shows multiple subcortical white matter hyperintensities <img src='img/arrows/WS.png'/> with hyperintense hypothalamus and optic tracts <img src='img/arrows/WO.png'/> in a child with ADEM.](8da64dd1-b711-403a-a9e1-abc258cd7523)
**Demyelinating Disease**
*Axial FLAIR MR shows multiple subcortical white matter hyperintensities <img src='img/arrows/WS.png'/> with hyperintense hypothalamus and optic tracts <img src='img/arrows/WO.png'/> in a child with ADEM.*
![Sagittal T2 MR shows classic pilocytic astrocytoma <img src='img/arrows/WS.png'/> originating from hypothalamus and optic chiasm. (Courtesy P. Rodriguez, MD).](images/app.statdx.com_image_thumbnail_515fc21f-f42d-409c-afc8-76fc1d6d4070_annotated_true_size_900_quality_90_b0c03410.jpg)
**Astrocytoma**
*Sagittal T2 MR shows classic pilocytic astrocytoma <img src='img/arrows/WS.png'/> originating from hypothalamus and optic chiasm. (Courtesy P. Rodriguez, MD).*
![Sagittal T1 C+ MR shows an inhomogeneously enhancing mass in the anterior 3rd ventricle, hypothalamus <img src='img/arrows/WS.png'/>.](images/app.statdx.com_image_thumbnail_d4da8508-123e-44f5-9394-817f216bb0dd_annotated_true_size_900_quality_90_96da8382.jpg)
**Astrocytoma**
*Sagittal T1 C+ MR shows an inhomogeneously enhancing mass in the anterior 3rd ventricle, hypothalamus <img src='img/arrows/WS.png'/>.*
![Sagittal T1 MR shows large, hyperintense craniopharyngioma originating from the 3rd ventricle <img src='img/arrows/BS.png'/> and hypothalamus. Note sparing of the suprasellar cistern <img src='img/arrows/BO.png'/>.](images/app.statdx.com_image_thumbnail_00698622-649b-49d5-a2cf-587247acab43_annotated_true_size_900_quality_90_6e54bad0.jpg)
**Craniopharyngioma**
*Sagittal T1 MR shows large, hyperintense craniopharyngioma originating from the 3rd ventricle <img src='img/arrows/BS.png'/> and hypothalamus. Note sparing of the suprasellar cistern <img src='img/arrows/BO.png'/>.*
![Sagittal T1 C+ MR in 13-year-old boy with central diabetes insipidus shows an enhancing mass in the anterior 3rd ventricle/hypothalamus <img src='img/arrows/WS.png'/> displacing the pituitary stalk <img src='img/arrows/WC.png'/> anteriorly.](707ec5e7-4e75-45fc-91a2-f5bebc3e98ad)
**Germ Cell Tumor**
*Sagittal T1 C+ MR in 13-year-old boy with central diabetes insipidus shows an enhancing mass in the anterior 3rd ventricle/hypothalamus <img src='img/arrows/WS.png'/> displacing the pituitary stalk <img src='img/arrows/WC.png'/> anteriorly.*
![Sagittal T1 C+ MR shows an enhancing mass infiltrating the hypothalamus <img src='img/arrows/WS.png'/> and infundibular stalk. The patient is an adult who presented with diabetes insipidus (DI).](1ad25312-dfdc-4eae-bb8f-ec4cb3f91874)
**Neurosarcoid**
*Sagittal T1 C+ MR shows an enhancing mass infiltrating the hypothalamus <img src='img/arrows/WS.png'/> and infundibular stalk. The patient is an adult who presented with diabetes insipidus (DI).*
![Sagittal T1 C+ MR in child with DI shows enhancing mass <img src='img/arrows/WS.png'/> infiltrating the hypothalamus, tuber cinereum, infundibular stalk, and pituitary gland.](e822f905-eff2-4b22-8231-04e49357f357)
**Langerhans Cell Histiocytosis**
*Sagittal T1 C+ MR in child with DI shows enhancing mass <img src='img/arrows/WS.png'/> infiltrating the hypothalamus, tuber cinereum, infundibular stalk, and pituitary gland.*
![Sagittal T1 C+ MR shows enhancing mass in anterior 3rd ventricle, hypothalamus <img src='img/arrows/WS.png'/>. The pituitary stalk <img src='img/arrows/WO.png'/> is slightly thickened.](55f14ad7-1168-45df-a768-38bb65ab25b4)
**Lymphocytic Hypophysitis**
*Sagittal T1 C+ MR shows enhancing mass in anterior 3rd ventricle, hypothalamus <img src='img/arrows/WS.png'/>. The pituitary stalk <img src='img/arrows/WO.png'/> is slightly thickened.*
![Sagittal T1 C+ FS MR shows pituitary <img src='img/arrows/WS.png'/>, hypothalamic <img src='img/arrows/WO.png'/> masses in this patient with proven B-cell lymphoma.](13dd8ba0-0338-411e-b549-ddf6b260c3d4)
**Lymphoma**
*Sagittal T1 C+ FS MR shows pituitary <img src='img/arrows/WS.png'/>, hypothalamic <img src='img/arrows/WO.png'/> masses in this patient with proven B-cell lymphoma.*
![Sagittal T2WI MR in a 12-year-old child with gelastic seizures shows a sessile hypothalamic mass <img src='img/arrows/WS.png'/> with a cyst <img src='img/arrows/WO.png'/>. No enhancement was seen on T1 C+ MR Variant cases may mimic astrocytoma.](0f44d562-1b8d-4194-817a-2bfdf12cc80b)
**Tuber Cinereum Hamartoma**
*Sagittal T2WI MR in a 12-year-old child with gelastic seizures shows a sessile hypothalamic mass <img src='img/arrows/WS.png'/> with a cyst <img src='img/arrows/WO.png'/>. No enhancement was seen on T1 C+ MR Variant cases may mimic astrocytoma.*
![Sagittal T1 MR in this 65-year-old patient shows an isointense hypothalamic/3rd ventricular mass <img src='img/arrows/WS.png'/> displacing and compressing optic chiasm <img src='img/arrows/WC.png'/>. Intense homogeneous enhancement was seen on T1 C+ study.](038aacce-b74b-4dc4-a99d-9500ba650cb7)
**Chordoid Glioma**
*Sagittal T1 MR in this 65-year-old patient shows an isointense hypothalamic/3rd ventricular mass <img src='img/arrows/WS.png'/> displacing and compressing optic chiasm <img src='img/arrows/WC.png'/>. Intense homogeneous enhancement was seen on T1 C+ study.*
![Sagittal T2 MR in a 3-year-old child with neurofibromatosis type 1 and diencephalic syndrome shows a large, hyperintense hypothalamic mass bulging into the anterior 3rd ventricle <img src='img/arrows/BS.png'/>.](82dcf44d-4527-458f-8f1a-40825822f3d8)
**Pilomyxoid Astrocytoma**
*Sagittal T2 MR in a 3-year-old child with neurofibromatosis type 1 and diencephalic syndrome shows a large, hyperintense hypothalamic mass bulging into the anterior 3rd ventricle <img src='img/arrows/BS.png'/>.*
![Sagittal T1 C+ MR in a 22-year-old woman with hypopituitarism shows a large, enhancing hypothalamic/infundibular stalk mass <img src='img/arrows/WC.png'/>.](77bec59a-d7f2-41a4-89c4-59cc60f1aa08)
**Pituicytoma**
*Sagittal T1 C+ MR in a 22-year-old woman with hypopituitarism shows a large, enhancing hypothalamic/infundibular stalk mass <img src='img/arrows/WC.png'/>.*
![Sagittal FLAIR MR shows multifocal hyperintensities along the callososeptal interface and in the hemispheric white matter as well as optic chiasm/hypothalamus <img src='img/arrows/BO.png'/>. This is a known patient with multiple sclerosis.](b003778f-f961-4af7-a1db-b858f2f54d44)
**Demyelinating Disease**
*Sagittal FLAIR MR shows multifocal hyperintensities along the callososeptal interface and in the hemispheric white matter as well as optic chiasm/hypothalamus <img src='img/arrows/BO.png'/>. This is a known patient with multiple sclerosis.*
![Axial FLAIR MR in a patient with longstanding hyperalimentation shows hyperintensity in mammillary bodies as well as periaqueductal gray matter <img src='img/arrows/WS.png'/>.](353868cf-f797-449b-b065-f35d8757d6b9)
**Wernicke Encephalopathy**
*Axial FLAIR MR in a patient with longstanding hyperalimentation shows hyperintensity in mammillary bodies as well as periaqueductal gray matter <img src='img/arrows/WS.png'/>.*
![Axial T2 FS MR with fat saturation shows a hypointense hypothalamic mass <img src='img/arrows/CS.png'/>, which was hyperintense on noncontrast T1 images (not shown). Loss of signal with fat saturation is compatible with fatty composition in this hypothalamic lipoma.](abd4645d-1afc-43a6-a353-4bfc1a3fe222)
**Lipoma**
*Axial T2 FS MR with fat saturation shows a hypointense hypothalamic mass <img src='img/arrows/CS.png'/>, which was hyperintense on noncontrast T1 images (not shown). Loss of signal with fat saturation is compatible with fatty composition in this hypothalamic lipoma.*
![Coronal T1 C+ FS MR shows multiple heterogeneous masses, consistent with metastases in a patient with known lung cancer. A specific metastatic lesion involves the hypothalamus <img src='img/arrows/CS.png'/>. There is edema and midline shift <img src='img/arrows/CO.png'/> from another metastatic mass (not shown).](02015ea3-14d9-42d7-9828-557c90ce1ffa)
**Metastases**
*Coronal T1 C+ FS MR shows multiple heterogeneous masses, consistent with metastases in a patient with known lung cancer. A specific metastatic lesion involves the hypothalamus <img src='img/arrows/CS.png'/>. There is edema and midline shift <img src='img/arrows/CO.png'/> from another metastatic mass (not shown).*
![Sagittal T1 C+ FS MR shows enhancing mass of the stalk and pituitary gland extending to the hypothalamus <img src='img/arrows/CS.png'/>. In a child with diabetes insipidus, this is consistent with Langerhans cell histiocytosis. There is an incidental pineal cyst <img src='img/arrows/CO.png'/>.](c8f20dbd-13ef-4948-94b4-01617752a1d7)
**Langerhans Cell Histiocytosis**
*Sagittal T1 C+ FS MR shows enhancing mass of the stalk and pituitary gland extending to the hypothalamus <img src='img/arrows/CS.png'/>. In a child with diabetes insipidus, this is consistent with Langerhans cell histiocytosis. There is an incidental pineal cyst <img src='img/arrows/CO.png'/>.*