An axial T1-weighted MRI scan showing ventriculomegaly and a superiorly displaced posterior fossa cyst. (medscape.com)
The sagittal T1-weighted MRI shows a large posterior fossa cyst that is compressing the cerebellar hemispheres, vermis, fourth ventricle (arrow), and brainstem. (medscape.com)
A sagittal T1-weighted magnetic resonance imaging (MRI) scan in a 5-year-old girl (also see the following 2 images) shows a large posterior fossa cyst elevating the torcular herophili and sinus rectus (short arrow). (medscape.com)
The hypoplastic vermis is everted over the posterior fossa cyst (long arrow). (medscape.com)
Cerebellar hemispheres1
An axial T2-weighted MRI scan that shows hydrocephalus, a large cerebrospinal fluid cyst in the posterior fossa, thinned occipital bone (arrows), and hypoplastic cerebellar hemispheres with a winged appearance (c). (medscape.com)
Atresia2
Dandy-Walker malformation may be associated with atresia of the foramen of Magendie and, possibly, the foramen of Luschka. (medscape.com)
Not until 1954 did Benda first emphasize that atresia of the cerebellar outlet foramina is not an essential feature of the condition and suggested the now widely accepted term Dandy-Walker malformation. (medscape.com)
Tumors1
Spontaneous nonparasitic actual tumors are those that develop early in life at the anterior pole of the splenic and are typically epidermoid, dermoid, or endodermal. (bvsalud.org)
Cystic2
Classically, posterior fossa cystic malformations have been divided into Dandy-Walker malformation, Dandy-Walker variant, mega cisterna magna, and posterior fossa arachnoid cyst. (medscape.com)
Background: Epidermoid cysts (ECs) are uncommon benign cystic lesions derived from the germinative epithelium. (bvsalud.org)
Uncommon1
Retrocerebellar arachnoid cysts of developmental origin (see the image below) are uncommon but clinically important. (medscape.com)
Surgical2
Because there are different surgical therapy approaches for posterior fossa arachnoid cyst and Dandy-Walker malformation, it is essential to differentiate between the 2 entities. (medscape.com)
Surgical therapy is suggested for symptomatic, large (more than 5 cm) cysts or complicated. (bvsalud.org)
Vermis1
Since the vermis is present in posterior fossa arachnoid cyst , this is considered separately from Dandy-Walker malformation. (medscape.com)
Significantly2
[ 15 ] A retrospective analysis of fetal MRIs with posterior fossa malformations found that Dandy-Walker malformation could be differentiated from Blake pouch cyst by a significantly higher tegmentovermian angle (TVA) at any gestational age. (medscape.com)
Using HFUS, the accuracy improved significantly for epidermoid cysts (59.6% vs. 86.7%), lipomas (50.6% vs. 94.8%), pilomatrixomas (0% vs. 48.0%), haemangiomas (23.8% vs. 57.1%), and DFSPs (0% vs. 81.8%) (all p (bvsalud.org)
Colloid cyst2
Endoscopic ultrasonic aspirator-assisted removal of a third ventricular colloid cyst. (amedeo.com)
For general consideration, diagnosis, evaluation, indications for the procedure and preoperative considerations related to colloid cysts , please refer to the chapter on Colloid Cyst: Transcallosal Approach . (neurosurgicalatlas.com)
Ventral2
7. Meningiomas of the ventral foramen magnum and lower clivus: factors influencing surgical morbidity, the extent of tumour resection, and tumour recurrence. (nih.gov)
An axial T2-weighted MRI scan that shows hydrocephalus, a large cerebrospinal fluid cyst in the posterior fossa, thinned occipital bone (arrows), and hypoplastic cerebellar hemispheres with a winged appearance (c). (medscape.com)
An axial T1-weighted MRI scan showing ventriculomegaly and a superiorly displaced posterior fossa cyst. (medscape.com)
Classically, posterior fossa cystic malformations have been divided into Dandy-Walker malformation, Dandy-Walker variant, mega cisterna magna, and posterior fossa arachnoid cyst. (medscape.com)
Since the vermis is present in posterior fossa arachnoid cyst, this is considered separately from Dandy-Walker malformation. (medscape.com)
Because there are different surgical therapy approaches for posterior fossa arachnoid cyst and Dandy-Walker malformation, it is essential to differentiate between the 2 entities. (medscape.com)
A posterior fossa arachnoid cyst in a 15-month-old girl with a lumbar pilonidal sinus. (medscape.com)
The sagittal T1-weighted MRI shows a large posterior fossa cyst that is compressing the cerebellar hemispheres, vermis, fourth ventricle (arrow), and brainstem. (medscape.com)
The membrane-wrapped cyst may lift and displace the posterior portion of the brain, as well as cause an internal obstruction of normal CSF flow, with resultant hydrocephalus. (medscape.com)
If the cyst is large, the foramen may be enlarged via transection of the septal vein as it joins the thalamostriate vein at the posterior edge of the foramen (upper image, inset). (neurosurgicalatlas.com)
Cerebellar1
CIM can be classified according to the extent of cerebellar tonsil tip into the foramen magnum being a protrusion over five mm considered pathological. (bvsalud.org)
Lateral2
Frameless stereotactic navigation is used to place a standard ventricular catheter into the frontal horn of the lateral ventricle aimed at the cyst or foramen of Monro (right image). (neurosurgicalatlas.com)
When compared with its transcallosal counterpart, it depends upon dilation of the ventricle, its exposure is somewhat limited, especially in its anteroposterior and lateral-medial working angles, and is therefore more appropriate for smaller lesions such as colloid cysts. (neurosurgicalatlas.com)
Frontal2
The frontal bone houses the supraorbital foramina, which, along with the frontal sinuses, form 2 important surgical landmarks during approaches involving the anterior skull base. (medscape.com)
The foramen cecum sits between the frontal crest and the prominent crista galli and is a site of communication between the draining veins of the nasal cavity and the superior sagittal sinus. (medscape.com)
Approach1
Endoscopic trans-septal interforniceal approach for excision of colloid cysts of the third ventricle using the rotational technique. (amedeo.com)
Lower1
The final view of the operative field after transection of the septal vein and removal of the cyst is shown (lower photo). (neurosurgicalatlas.com)
Image1
Retrocerebellar arachnoid cysts of developmental origin (see the image below) are uncommon but clinically important. (medscape.com)