415 lines
41 KiB
Markdown
415 lines
41 KiB
Markdown
---
|
||
title: "Pineal Region Mass, General"
|
||
docid: "7eb4aa6f-a67b-4ed2-adee-469808038024"
|
||
authors:
|
||
- key: "f184750a-90b4-47a7-907b-23b05d70357a"
|
||
value: "Chang Yueh Ho, MD"
|
||
- key: "83f867a5-a183-4396-82ea-384015da4d2f"
|
||
value: "Gregory L. Katzman, MD, MBA"
|
||
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: "Pineal Region Mass, General"
|
||
slug: "pineal-region-mass-general"
|
||
treeNodeId: null
|
||
category: "Brain"
|
||
documentVersionId: "6168b658-5788-4456-9eb6-f1cd396df6ac"
|
||
imageCount: 56
|
||
lastUpdated: "02/02/23"
|
||
pageDescription: "Pineal Region Mass, General"
|
||
pageKeywords: "Brain, Differential Diagnosis, Sella/Juxtasellar, Pineal Region, Anatomically Based Differentials, Pineal Region Mass, General"
|
||
pageTitle: "Pineal Region Mass, General | STATdx"
|
||
enhancedTitle: "Pineal Region Mass, General"
|
||
type: "DDX"
|
||
references: true
|
||
breadcrumbs:
|
||
- "Brain"
|
||
- "Differential Diagnosis"
|
||
- "Sella/Juxtasellar, Pineal Region"
|
||
- "Anatomically Based Differentials"
|
||
- "Pineal Region Mass, General"
|
||
---
|
||
# ESSENTIAL INFORMATION
|
||
|
||
- ## Key Differential Diagnosis Issues
|
||
|
||
|
||
- Quadrigeminal cistern
|
||
- Bounded by quadrigeminal plate, splenium, vermis, & tentorial margin
|
||
- Extends between layers of 3rd ventricle tela choroidea
|
||
- Contents: Caudal internal cerebral veins → vein of Galen, distal parts of quadrigeminal artery, posterior cerebral artery P4 segment, & CNIX exit
|
||
- Synonyms: Cisterna quadrigeminalis, cistern of great cerebral vein, cisterna venae magnae cerebri, Bichat canal, cisternal quadrigeminalis, & superior cistern
|
||
- ## Helpful Clues for Common Diagnoses
|
||
|
||
|
||
- **Pineal Cyst**
|
||
- Homogeneous fluid-filled mass distinct from tectum
|
||
- 55-60% slightly T1 hyperintense to CSF; incomplete FLAIR suppression; 60% rim enhancement
|
||
- Cystic expansion of pineal in some female patients begins in adolescence, decreases with age
|
||
- Indistinguishable from cystic pineocytoma on basis of imaging studies alone
|
||
- **Germ Cell Tumors**
|
||
- Pineal region mass that engulfs pineal gland Ca⁺⁺
|
||
- Male predominance in pineal region
|
||
- **Germinoma**
|
||
- T1/T2 iso- or hyperintense to gray matter
|
||
- Strong uniform enhancement ± CSF seeding
|
||
- CT hyperdense, diffusion restriction
|
||
- **Teratoma**
|
||
- Mature tumors with Ca⁺⁺, cysts, & fat
|
||
- Immature tumors with heterogeneous enhancement & predominantly soft tissue
|
||
- Teratoma with somatic-type malignancy, typically sarcoma or carcinoma
|
||
- **Nongerminomatous germ cell tumors**
|
||
- Choriocarcinoma, endodermal sinus tumor, embryonal cell carcinoma, mixed germ cell tumor
|
||
- Heterogeneously enhancing pineal mass
|
||
- Elevation of serum β-hCG &/or α-fetal protein
|
||
- **Pineal Parenchymal Tumors**
|
||
- Enhancing, pineal mass that explodes pineal Ca⁺⁺
|
||
- **Pineoblastoma**
|
||
- Large heterogeneous mass, adjacent invasion
|
||
- Evaluate neuraxis for leptomeningeal dissemination
|
||
- ~ 35-45% of pineal parenchymal tumors
|
||
- WHO grade 4
|
||
- **Pineocytoma**
|
||
- Enhancing, circumscribed pineal mass
|
||
- May mimic normal pineal gland & cyst
|
||
- Compresses but does not invade adjacent structures
|
||
- ~ 25% of pineal parenchymal tumors
|
||
- WHO grade 1
|
||
- **Pineal parenchymal tumor of intermediate differentiation**
|
||
- Typically larger, heterogeneous, & more aggressive than pineocytomas
|
||
- Intermediate grade between blastoma & cytoma
|
||
- Leptomeningeal dissemination has been described
|
||
- ~ 20-45% of pineal parenchymal tumors
|
||
- WHO grade 2-3
|
||
- **Papillary tumor of pineal region**
|
||
- Rare tumors thought to arise from ependymocytes in subcommissural organ
|
||
- May have T1 hyperintensity from glycopeptides
|
||
- Heterogeneous enhancement, possible CSF dissemination
|
||
- WHO grade 2 or 3
|
||
- **Desmoplastic myxoid tumor of pineal region,***SMARCB1***-mutant**
|
||
- Rare adolescent to adult tumor, intermediate prognosis
|
||
- Similar appearance to other pineal gland tumors
|
||
- ## Helpful Clues for Less Common Diagnoses
|
||
|
||
|
||
- **Cyst of Velum Interpositum**
|
||
- Triangular CSF space between lateral ventricles
|
||
- Cavum velum interpositum common in infants, rare in adults
|
||
- Large cyst inferiorly displaces internal cerebral veins
|
||
- Splays & elevates fornices
|
||
- **Arachnoid Cyst**
|
||
- Sharply demarcated extraaxial cyst that follows CSF attenuation/signal
|
||
- Quadrigeminal arachnoid cysts (AC) are 3rd most common infratentorial AC
|
||
- Symptoms depend on compression of brainstem, cerebellum, & aqueduct
|
||
- Elevates internal cerebral veins
|
||
- **Midbrain & Thalamic Neoplasms**
|
||
- Astrocytomas of tectal plate most common
|
||
- Diffuse midline glioma, H3 K27-altered, atypical teratoid/rhabdoid tumor, CNS embryonal tumors
|
||
- **Tectal plate glioma**
|
||
- Tectal distortion or thickening by localized mass
|
||
- T1 hypointense, T2 hyperintense, rare enhancement
|
||
- Onset aqueductal stenosis often without brainstem signs
|
||
- Indolent, often remaining stable in size for many years
|
||
- **Neurocysticercosis**
|
||
- May involve cisterns > parenchyma > ventricles
|
||
- Basal cistern cysts may be racemose or grape-like
|
||
- Cysts variable in size & may contain 1- to 4-mm scolex
|
||
- Cystic lesion isointense to CSF, may see discrete, eccentric scolex
|
||
- **Lipoma**
|
||
- Well-delineated lobulated extraaxial mass with fat attenuation/intensity
|
||
- 40-50% interhemispheric fissure (over corpus callosum)
|
||
- Ca⁺⁺ varies from none to extensive
|
||
- Fat-suppressed MR is diagnostic
|
||
- **Intracranial Hypotension**
|
||
- Corpus callosal descent can efface quadrigeminal cistern
|
||
- Sagittal image shows brain descent in 40-50%
|
||
- Diffusely, intensely enhancing dura in 85%
|
||
- Bilateral subdural fluid collections in 15%
|
||
- ## Helpful Clues for Rare Diagnoses
|
||
|
||
|
||
- **Epidermoid Cyst**
|
||
- Lobulated, irregular, CSF-like mass with fronds insinuates cistern
|
||
- Incomplete FLAIR suppression; decreased diffusion
|
||
- ~ 1-2% of all primary intracranial tumors
|
||
- Congenital inclusion cysts; rare malignant degeneration into squamous cell CA
|
||
- **Dermoid Cyst**
|
||
- Fat-suppression sequence or negative HU to confirm fat
|
||
- Rupture → fat droplets in subarachnoid spaces with diffuse enhancement from chemical meningitis
|
||
- < 0.5% of primary intracranial tumors
|
||
- Rare malignant degeneration into squamous cell carcinoma
|
||
- **Vein of Galen Malformation**
|
||
- Misnomer: Arteriovenous fistula draining into enlarged median prosencephalic vein
|
||
- Dilated arteries feeding into large midline venous pouch
|
||
- < 1% cerebral vascular malformations at any age
|
||
- Neonatal > infant presentation most common; rare adult presentation
|
||
- **Meningioma**
|
||
- Avidly enhancing mass, trapped pools of CSF common
|
||
- Arise from posterior portion of velum interpositum, falx, or tentorium
|
||
- Velum interpositum meningiomas: M = F, in both pediatric & adult populations
|
||
- May be symptomatic from compression of quadrigeminal plate
|
||
|
||
## References
|
||
|
||
# Selected References
|
||
|
||
1. [Takase H et al: Pineal parenchymal tumor of intermediate differentiation: a systematic review and contemporary management of 389 cases reported during the last two decades. Neurosurg Rev. 45(2):1135-55, 2022](http://www.ncbi.nlm.nih.gov/pubmed/?term=34668090%5Bpmid%5D)
|
||
1. [Favero G et al: Pineal gland tumors: a review. Cancers (Basel). 13(7), 2021](http://www.ncbi.nlm.nih.gov/pubmed/?term=33801639%5Bpmid%5D)
|
||
1. [Tanaka T et al: Pineal cysts: does anyone need long-term follow up? J Clin Neurosci. 83:146-51, 2021](http://www.ncbi.nlm.nih.gov/pubmed/?term=33272885%5Bpmid%5D)
|
||
1. [Gilbert AR et al: Extending the neuroanatomic territory of diffuse midline glioma, K27M mutant: pineal region origin. Pediatr Neurosurg. 53(1):59-63, 2018](http://www.ncbi.nlm.nih.gov/pubmed/?term=29131126%5Bpmid%5D)
|
||
1. [Tamrazi B et al: Pineal region masses in pediatric patients. Neuroimaging Clin N Am. 27(1):85-97, 2017](http://www.ncbi.nlm.nih.gov/pubmed/?term=27889025%5Bpmid%5D)
|
||
1. [Smith AB et al: From the archives of the AFIP: lesions of the pineal region: radiologic-pathologic correlation. Radiographics. 30(7):2001-20, 2010](http://www.ncbi.nlm.nih.gov/pubmed/?term=21057132%5Bpmid%5D)
|
||
|
||
|
||
## Images
|
||
|
||
|
||
### Selected Images
|
||
|
||
|
||
**Pineal Cyst**
|
||
*Sagittal T1 C+ MR shows a nonenhancing cyst <img src='img/arrows/CS.png'/> in the pineal region related to a pineal cyst. These benign cysts typically require no follow-up.*
|
||
|
||
|
||
**Pineal Cyst**
|
||
*Sagittal T1 C+ MR shows a nonenhancing cyst <img src='img/arrows/CS.png'/> in the pineal region related to a pineal cyst. These benign cysts typically require no follow-up.*
|
||
|
||
|
||
**Germinoma**
|
||
*Axial b=1000 DWI shows a pineal region mass with decreased diffusion & thalamic invasion. Note the central susceptibility artifact from engulfed Ca++ <img src='img/arrows/CS.png'/>. Pure germinomas are hypercellular & typically show decreased diffusion. Engulfed Ca++ favors germinoma over pineoblastoma. Germinomas are the most common pineal region mass.*
|
||
|
||
|
||
**Teratoma**
|
||
*Sagittal T1 MR shows a heterogeneous mass with intrinsic T1 shortening, consistent with fat <img src='img/arrows/CS.png'/>. In this infant, fat content & midline location suggest teratoma.*
|
||
|
||
|
||
**Pineoblastoma**
|
||
*Sagittal T1 C+ MR shows an enhancing mass of the pineal region with mass effect on the tectal plate <img src='img/arrows/CO.png'/> & midbrain with resulting hydrocephalus <img src='img/arrows/CC.png'/>. Pineoblastomas often have CSF dissemination.*
|
||
|
||
|
||
**Pineoblastoma**
|
||
*Axial b=1000 DWI (same patient) shows the almond-shaped mass has intense decreased diffusion, consistent with hypercellularity. Pineoblastomas are WHO grade 4 small round blue cell embryonal tumors & should be considered for any pineal region tumor with decreased diffusion.*
|
||
|
||
|
||
**Pineocytoma**
|
||
*Sagittal T2 MR shows a bubbly, cystic mass of pineal gland <img src='img/arrows/CS.png'/> in a patient with a headache likely from hydrocephalus. Note lack of flow void through cerebral aqueduct <img src='img/arrows/CC.png'/> from mass effect on tectal plate, a WHO grade 1 pineocytoma at resection.*
|
||
|
||
|
||
**Pineal Parenchymal Tumor of Intermediate Differentiation**
|
||
*Sagittal T1 C+ MR shows a lobular enhancing mass <img src='img/arrows/CS.png'/> in the pineal region causing obstructive hydrocephalus <img src='img/arrows/CC.png'/>. This was a pineal parenchymal tumor of intermediate differentiation at resection.*
|
||
|
||
|
||
**Papillary Tumor of Pineal Region**
|
||
*Sagittal T2 MR shows a bubbly cystic tumor in the pineal region <img src='img/arrows/CS.png'/> causing mass effect on the tectum. A papillary tumor of the pineal region may show greater cystic changes than other pineal parenchymal tumors. Associated hydrocephalus is common. These rare tumors may be WHO grade 2 or 3.*
|
||
|
||
|
||
**Cyst of Velum Interpositum**
|
||
*Axial T2 MR shows a cystic structure between the leaves of the velum interpositum <img src='img/arrows/CC.png'/>. Note there is a lack of extension anteriorly to involve the septum pellucidum.*
|
||
|
||
|
||
**Cyst of Velum Interpositum**
|
||
*Sagittal T1 C+ MR shows the nonenhancing cyst <img src='img/arrows/CS.png'/> that displaces the internal cerebral veins inferiorly <img src='img/arrows/CC.png'/>. The majority of cysts or masses in the pineal region will typically splay or elevate the internal cerebral veins.*
|
||
|
||
|
||
**Arachnoid Cyst**
|
||
*Axial FLAIR MR demonstrates a FLAIR- suppressed cyst in the pineal region <img src='img/arrows/CS.png'/>. This follows CSF on all sequences & is related to an arachnoid cyst.*
|
||
|
||
|
||
**Tectal Plate Glioma**
|
||
*Axial FLAIR MR shows a T2-hyperintense mass in the tectal plate & dorsal brainstem <img src='img/arrows/CS.png'/>. This did not demonstrate enhancement (not shown) & causes aqueductal obstruction leading to hydrocephalus <img src='img/arrows/CC.png'/>. Tectal gliomas are commonly low-grade tumors. However, a variety of of tumor types may involve the tectal plate.*
|
||
|
||
|
||
**Lipoma**
|
||
*Axial T1 MR shows an intrinsic T1-hyperintense homogeneous mass along the tectal plate <img src='img/arrows/CS.png'/>. This is consistent with lipoma. Intracranially, lipomas typically occur midline from maldifferentiation of the embryologic meninx primitiva & can be associated malformations.*
|
||
|
||
|
||
**Epidermoid Cyst**
|
||
*Axial b=1000 DWI shows a hyperintense lobular mass in the pineal region & 3rd ventricle. This had cyst-like T1 & T2 signal with incomplete FLAIR suppression & no enhancement (not shown), classic for epidermoid cyst.*
|
||
|
||
|
||
**Vein of Galen Malformation**
|
||
*Sagittal T2 MR shows a large flow void from enlargement of the median prosencephalic vein <img src='img/arrows/CS.png'/>. Note the enlargement of the pericallosal arteries <img src='img/arrows/CO.png'/> & vertebrobasilar arteries <img src='img/arrows/CC.png'/>, which fistulize into the aneurysmal vein. This causes steal phenomenon & high-output cardiac failure with resulting cerebral atrophy.*
|
||
|
||
|
||
**Meningioma**
|
||
*Axial T1 C+ MR shows a homogeneous enhancing mass in the pineal region. Note the border with the posterior falx <img src='img/arrows/CS.png'/>, suggesting a broad dural base, typical of meningioma.*
|
||
|
||
|
||
### Additional Images
|
||
|
||
|
||
**Pineal Cyst**
|
||
*Sagittal T1 C+ MR shows how difficult pineal cysts <img src='img/arrows/WS.png'/> can be to distinguish from pineocytoma. Pineal cysts can display a spectrum of enhancement from thin to thick rim to nodular.*
|
||
|
||
|
||
**Pineal Cyst**
|
||
*Axial FLAIR MR shows the classic finding of a presumed pineal cyst <img src='img/arrows/WS.png'/> that does not suppress & is moderately hyperintense.*
|
||
|
||
|
||
**Germinoma**
|
||
*Axial T1 C+ MR demonstrates that germinomas can present with synchronous masses. These will typically be in the pineal <img src='img/arrows/BS.png'/> & suprasellar <img src='img/arrows/BO.png'/> locations.*
|
||
|
||
|
||
**Germinoma**
|
||
*Sagittal T1 C+ MR shows an enhancing germinoma <img src='img/arrows/BC.png'/>. Note compression of the tectal plate <img src='img/arrows/BS.png'/> and CSF tumor seeding <img src='img/arrows/WO.png'/>.*
|
||
|
||
|
||
**Pineal Parenchymal Tumors**
|
||
*Coronal T1 C+ MR shows a typical MR case of small, cystic, centrally & peripherally enhancing <img src='img/arrows/WC.png'/> pineocytoma.*
|
||
|
||
|
||
**Pineal Parenchymal Tumors**
|
||
*Axial CECT shows a typical CT case of a pineocytoma with "exploded" preexisting Ca++ <img src='img/arrows/WS.png'/>. Also note the typical lack of significant mass effect.*
|
||
|
||
|
||
**Cyst of Velum Interpositum**
|
||
*Axial CECT shows a CSF collection between the fornices <img src='img/arrows/WS.png'/>, splaying the internal cerebral veins & choroid plexus inferolaterally <img src='img/arrows/WO.png'/>. Note the septum pellucidum <img src='img/arrows/WC.png'/> is intact.*
|
||
|
||
|
||
**Cyst of Velum Interpositum**
|
||
*Axial T2WI MR demonstrates a classic CVI appearance: Triangular-shaped CSF collection between the fornices <img src='img/arrows/BS.png'/>.*
|
||
|
||
|
||
**Arachnoid Cyst**
|
||
*Axial FLAIR MR shows a quadrigeminal cistern arachnoid cyst which followed CSF on all sequences & shows complete FLAIR suppression <img src='img/arrows/WS.png'/>.*
|
||
|
||
|
||
**Arachnoid Cyst**
|
||
*Sagittal T1WI MR shows an arachnoid cyst extending posteroinferiorly from the quadrigeminal cistern, compressing the superior vermis inferiorly <img src='img/arrows/BS.png'/>.*
|
||
|
||
|
||
**Midbrain & Thalamic Neoplasms**
|
||
*Sagittal T2WI MR demonstrates a typical tectal plate low-grade astrocytoma as a predominantly homogeneous, slightly hyperintense mass involving the tectal plate proper <img src='img/arrows/BS.png'/>.*
|
||
|
||
|
||
**Neurocysticercosis**
|
||
*Axial T2WI FS MR shows multiple cysticercosis cysts in the quadrigeminal cistern <img src='img/arrows/BS.png'/>, atrium right lateral ventricle <img src='img/arrows/BO.png'/>. (Courtesy E. Bravo, MD.)*
|
||
|
||
|
||
**Neurocysticercosis**
|
||
*Axial T2WI MR shows a typical case of racemose (grape-like) cisternal neurocysticercosis within the quadrigeminal plate & ambient cisterns <img src='img/arrows/BC.png'/>.*
|
||
|
||
|
||
**Lipoma**
|
||
*Axial T1WI MR reveals a fat-intensity lesion <img src='img/arrows/WS.png'/> within the quadrigeminal cistern exerting mass effect upon the quadrigeminal plate (R > L). Fat suppression (not shown) confirmed lipoma.*
|
||
|
||
|
||
**Lipoma**
|
||
*Axial T1 C+ FS MR confirms the presence of a lipoma <img src='img/arrows/WS.png'/> that was T1 hyperintense (not shown).*
|
||
|
||
|
||
**Intracranial Hypotension**
|
||
*Sagittal T1 C+ MR in a patient with intracranial hypotension shows cisternal effacement by the splenium <img src='img/arrows/WS.png'/> impacting the internal cerebral veins <img src='img/arrows/WC.png'/> & quadrigeminal plate <img src='img/arrows/WO.png'/>. Note loss of the suprasellar cistern <img src='img/arrows/BS.png'/> & dural enhancement <img src='img/arrows/BO.png'/>.*
|
||
|
||
|
||
**Epidermoid Cyst**
|
||
*Axial T2WI MR shows a T2 hyperintense lobulated mass centered in ambient cistern <img src='img/arrows/WS.png'/> extending into suprasellar <img src='img/arrows/WC.png'/> & quadrigeminal cisterns <img src='img/arrows/WO.png'/> displacing the quadrigeminal plate <img src='img/arrows/BO.png'/>.*
|
||
|
||
|
||
**Epidermoid Cyst**
|
||
*Coronal T1WI MR reveals a small T1 hypointense epidermoid <img src='img/arrows/WS.png'/> within the quadrigeminal cistern with mild mass effect displacing bilateral cerebral & cerebellar hemispheres.*
|
||
|
||
|
||
**Dermoid Cyst**
|
||
*Sagittal T1WI MR shows a ruptured dermoid with intrinsic mixed signal <img src='img/arrows/WO.png'/>, lipid droplets present throughout the subarachnoid spaces <img src='img/arrows/WC.png'/>, & hydrocephalus <img src='img/arrows/WS.png'/> from chemical meningitis.*
|
||
|
||
|
||
**Dermoid Cyst**
|
||
*Axial CECT demonstrates a low-density ruptured dermoid in the pineal region <img src='img/arrows/WO.png'/> with fat droplets in subarachnoid spaces <img src='img/arrows/WS.png'/>. Note ventricular shunt <img src='img/arrows/WC.png'/> placed for chemical meningitis.*
|
||
|
||
|
||
**Vein of Galen Malformation**
|
||
*Lateral angiography shows an enlarged vein of Galen, falcine sinus, & augmented flow into superior sagittal sinus <img src='img/arrows/BS.png'/>, supplied by enlarged choroidal & thalamoperforating arteries <img src='img/arrows/BC.png'/>.*
|
||
|
||
|
||
**Vein of Galen Malformation**
|
||
*Sagittal T1WI MR shows a large well-delineated area of signal loss behind the 3rd ventricle <img src='img/arrows/WO.png'/>. Note phase artifact from high flow <img src='img/arrows/WC.png'/> & large persistent primitive falcine sinus <img src='img/arrows/WS.png'/>.*
|
||
|
||
|
||
**Meningioma**
|
||
*Sagittal T2WI FS MR shows an isointense mass <img src='img/arrows/WS.png'/> with flow voids <img src='img/arrows/WC.png'/>. Visualization of a normal pineal gland <img src='img/arrows/BS.png'/> & elevation of midbrain tectum <img src='img/arrows/BO.png'/> helps exclude pineal tumors from the differential diagnosis.*
|
||
|
||
|
||
**Meningioma**
|
||
*Sagittal T1 C+ MR reveals a small, rounded, avidly enhancing, falcotentorial meningioma without quadrigeminal plate abutment.*
|
||
|
||
|
||
**Pineal Cyst**
|
||
*Axial T2 MR shows a cystic lesion <img src='img/arrows/CS.png'/> in the expected location of the pineal gland. This large pineal cyst is causing obstruction of the distal 3rd ventricle & aqueduct with hydrocephalus <img src='img/arrows/CO.png'/>.*
|
||
|
||
|
||
**Germinoma**
|
||
*Sagittal T1 C+ FS MR shows a lobular enhancing mass in the pineal region. The central hypointensity <img src='img/arrows/CS.png'/> is consistent with an engulfed pineal calcification consistent with germ cell tumors. Compared with other germ cell tumors, germinomas are typically homogeneous with rapid response to chemotherapy.*
|
||
|
||
|
||
**Teratoma**
|
||
*Axial T1 C+ MR in an infant shows a lobular heterogeneously enhancing tumor <img src='img/arrows/CS.png'/> in the pineal region causing obstructive hydrocephalus <img src='img/arrows/CO.png'/>. This was a mature teratoma at resection.*
|
||
|
||
|
||
**Nongerminomatous Germ Cell Tumors**
|
||
*Sagittal T1 C+ FS MR shows a heterogeneous enhancing mass in the pineal region with a central hypointensity <img src='img/arrows/CS.png'/> from an engulfed pineal Ca++. There is a large lobular enhancing lesion in the 4th ventricle <img src='img/arrows/CO.png'/> from leptomeningeal dissemination of this mixed germ cell tumor.*
|
||
|
||
|
||
**Pineoblastoma**
|
||
*Axial NECT shows an isodense pineal mass <img src='img/arrows/CO.png'/> with eccentric pineal Ca++ <img src='img/arrows/CS.png'/> causing hydrocephalus. Pineoblastomas & other pineal parenchymal tumors typically explode calcifications. Germ cell tumor arises from germ cell rests outside of the pineal gland & engulfs Ca++.*
|
||
|
||
|
||
**Pineocytoma**
|
||
*Sagittal T1 C+ MR shows a homogeneous enhancing mass <img src='img/arrows/CS.png'/> in the pineal region with mass effect on the tectal plate. This was a low-grade pineocytoma at resection.*
|
||
|
||
|
||
**Pineal Parenchymal Tumor of Intermediate Differentiation**
|
||
*Axial T1 C+ FS shows an oblong pineal tumor, which causes obstructive hydrocephalus. Pineal parenchymal tumors of intermediate differentiation are WHO grade 2 tumors in between pineocytoma & pineoblastoma.*
|
||
|
||
|
||
**Cyst of Velum Interpositum**
|
||
*Sagittal T1 MR shows a cystic mass causing anterior displacement of the fornix <img src='img/arrows/CS.png'/> & downward displacement of the tectal plate & internal cerebral veins <img src='img/arrows/CO.png'/>. Note the pineal parenchyma posterior to the cyst <img src='img/arrows/CC.png'/>. This is an arachnoid cyst within a cavum velum interpositum.*
|
||
|
||
|
||
**Arachnoid Cyst**
|
||
*Axial T2 FS MR shows a cyst <img src='img/arrows/CS.png'/> in the pineal region causing mass effect on the midbrain with resulting hydrocephalus. This cyst was inferior to the pineal gland (not shown).*
|
||
|
||
|
||
**Tectal Plate Glioma**
|
||
*Axial FLAIR MR shows a hyperintense mass arising from the tectal plate <img src='img/arrows/CS.png'/>. This is consistent with a tectal plate glioma. These are low-grade astrocytomas, which typically grow very slowly. Hydrocephalus from aqueductal stenosis is typically managed with shunting. Note the artifact from a shunt reservoir <img src='img/arrows/CO.png'/>.*
|
||
|
||
|
||
**Lipoma**
|
||
*Axial T1 MR shows a T1 hyperintense mass associated with the quadrigeminal plate. This mass showed signal loss on a fat saturation sequence (not shown) consistent with lipoma.*
|
||
|
||
|
||
**Meningioma**
|
||
*Sagittal T1 C+ MR shows a homogeneous enhancing mass arising below the pineal gland <img src='img/arrows/CS.png'/>. Note the broad dural base <img src='img/arrows/CO.png'/> with the tentorium & inferior displacement of the cerebellum from an extraaxial mass consistent with meningioma.*
|
||
|
||
|
||
**Epidermoid Cyst**
|
||
*Axial DWI shows a mass with central decreased diffusion arising from the pineal region & causing mass effect & hydrocephalus. On T1- & T2-weighted images, this approximated the appearance of a cyst typical for epidermoids. Incomplete FLAIR suppression is also typical.*
|
||
|
||
|
||
**Vein of Galen Malformation**
|
||
*Sagittal T1 C+ MR shows a heterogeneous mass in the pineal region with extension along the straight sinus <img src='img/arrows/CO.png'/> to a dilated torcula <img src='img/arrows/CS.png'/>. This child has a history of vein of Galen malformation treated with coiling, which causes the internal hypointense signal.*
|
||
|
||
|
||
**Neurocysticercosis**
|
||
*Sagittal T1 C+ MR shows a cystic lesion <img src='img/arrows/CC.png'/> below the pineal gland with faint wall enhancement. Another ring enhancing cyst with central enhancement is noted between the occipital lobes <img src='img/arrows/CO.png'/> consistent with the colloidal vesicular phase of neurocysticercosis.*
|
||
|
||
|
||
**Dermoid Cyst**
|
||
*Sagittal T1 MR shows a heterogeneous cystic lesion with internal T1 hyperintensity <img src='img/arrows/CS.png'/>. In addition, there are droplets of T1 hyperintensity along the adjacent leptomeninges <img src='img/arrows/CO.png'/> consistent with rupture of a dermoid cyst.*
|
||
|