Sara M. Koenig, MD Wilson B. Altmeyer, MD Carlos Bazan III, MD
Maria P. Valencia, MD
Slide 2
No financial disclosures
Slide 3
Our purpose is to review the collective radiographic findings
of common individual phakomatoses, focusing on: Neurofibromatosis I
and II Tuberous Sclerosis Sturge-Weber Ataxia Telangiectasia The
phakomatoses are multi-system disorders involving the
neurocutaneous tissues and other tissues throughout the body. These
disorders frequently demonstrate a large number of radiographic
findings that all radiologists should know, especially in
neuroradiologic imaging. Understanding the spectrum of the
radiographic findings for these diseases is important and may be
diagnostic, affect prognosis, or affect treatment.
Slide 4
A retrospective review of neuroradiology cases at the
University of Texas Health Science Center at San Antonio was
performed to identify patients with a diagnosis of phakomatosis.
Characteristic neurocutaneous findings and systemic manifestations
of the specific diseases were identified on imaging and organized
into a review of neuroradiologic and other findings in the
phakomatosis diseases. As well, we reviewed literature for imaging
of these diseases.
Slide 5
Multisystem neurocutaneous disorder Autosomal dominant
chromosome 17 mutation Most common phakomatosis The differential
includes: NF spectrum, Demyelination, Gliomatosis Cerebri
Diagnostic Criteria: (must have >2 of the following) ->6 cafe
au lait spots evident during 1 year -2 or > neurofibromas or 1
plexiform -Optic nerve glioma -Distinctive osseous lesion -Sphenoid
wing dysplasia -2 or > iris hamartomas (Lisch nodules) -Axillary
or inguinal freckling -1st relative with NF 1 with above criteria
Neuroimaging Findings -Focal areas of signal intensity in deep grey
/ white matter (myelin vacuolization) -Optic Nerve Glioma (manifest
with enlarged optic foramen) -Progressive sphenoid wing dysplasia
-Lambdoid suture defects -Dural calcification at vertex -Moya Moya
Phenomenon: rare -Buphthalmos
Slide 6
Sagittal T1WI shows enlarged isointense optic chiasm (arrow).
Coronal T1WI with Gd shows no abnormal enhancement of enlarged
optic chiasm (arrow). Coronal T2WI shows multiple bilateral rounded
paraspinal hyperintense lesions (arrows), consistent with
neurofibromas.
Slide 7
Coronal T1 + Gd and axial T2 weighted images demonstrating
optic pathway gliomas. Axial T2 FLAIR images showing hyperintense
supra and infratentorial lesions throughout the deep gray/white
matter, consistent with myelin vacuolization.
Slide 8
Axial T2 WI (top) and coronal FLAIR (bottom) images demonstrate
scattered hyperintense lesions throughout the deep gray/white
matter, most pronounced in the bilateral globus pallidi, thalami,
splenium of the corpus callosum and cerebellum.
Slide 9
Axial and coronal T2 FS images demonstrate thickening of the
bilateral optic nerves, right greater than left, consistent with
optic pathway gliomas.
Slide 10
Multisequence MRI demonstrates an infiltrative heterogeneous
solid enhancing right temporal scalp mass, extending into the right
orbit and right cavernous sinus. Please note the typical target
sign (arrow), presumable secondary to dense central area of
collagenous stroma. T1WI T2WI T1 + Gd
Slide 11
T2 FS sagittal and axial images of the lumbar spine demonstrate
multiple hyperintense well circumscribed lobulated lesions
consistent with neurofibromas along the bilateral nerve roots.
Slide 12
Multisystem neurocutaneous disorder secondary to an autosomal
dominant chromosome 22 abnormality. Diagnosis peaks in the 20s,
usually presenting with hearing loss from vestibular schwannomas.
Neuroimaging Findings -Schwannomas of cranial nerves and spinal
nerve roots -Meningiomas -Ependymomas -Most commonly intramedullary
spinal cord lesions
Slide 13
Axial T2WI shows bilateral intracanalicular lesions extending
from the porus acusticus (arrows). Axial T1WI + Gd shows solid
enhancement of the lesions (arrows), consistent with Schwannomas.
Sagittal T1WI + Gd shows dural based solid enhancing lesions along
the tentorium and anterior falx (arrows), consistent with
meningiomas.
Slide 14
Sagittal T1WI FS post contrast (left), Sagittal T2WI (center)
& Sagittal T2 STIR (right) images show well circumscribed,
solid enhancing, hyperintense T2/STIR expansile intramedullary
lesions, consistent with ependymomas.
Slide 15
-Axial T1WI and T2WI FS images (top) show an iso to
hyperintense intramedullary superior cervical cord lesion
consistent with ependymoma (white arrow). -Axial and Coronal T2WI
(bottom) show a circumscribed hyperintense lesion in the left
parapharyngeal space displacing the left carotid space vessels
antero-laterally, consistent with a left vagal nerve Schwannoma
(yellow arrow). T2WI T1WI T2WI
Slide 16
Sagittal T1W pre and post contrast images (left) showing
isointense solid enhancing spinal nerve root masses. Sagittal and
axial T2WI (right) showing hyperintense signal in those masses,
consistent with Schwannomas.
Slide 17
Autosomal dominant multisystem neurocutaneous disorder caused
by mutations of the TSC1 (9q) and TSC 2 (16p) genes. Can be
diagnosed with major and minor criteria. Clinical symptoms:
Seizures, facial nevus, mental deficiency Although there are many
features, most common are: Multiple partially calcified
subependymal nodules Subcortical tubers Radial migration of white
matter lines Subepependymal giant cell astrocytoma (SEGA) White
matter cyst-like lesions
Slide 18
Definite TS = 2 major OR 1 major + 2 minor criteria Probable TS
= 1 major + 1 minor criteria Possible TS = 1 major OR 2 minor
criteria Major Criteria Ungual or Periungual fibroma Facial
angiofibroma > 3 hypomelanotic macules Shagreen patch Multiple
retinal nodular hamartomas Cortical tubers Subependymal nodule
Subependymal Giant Cell Astrocytoma (SEGA) Cardiac Rhabdomyoma
Lymphangiomyosarcoma Renal angiomyolipoma Minor Criteria Multiple
dental/enamel pits Gingival fibromas Non-renal hamartoma Retinal
achromic patch Multiple renal cysts Bone cysts White matter
migration lines Multiple confetti-like hypopigmented skin
lesions
Slide 19
Axial CT image (left) demonstrating a calcified subependymal
nodule (arrow) at the atrium of the right lateral ventricle. Axial
and coronal T2W images (center & right) demonstrate multiple
hypointense subependymal nodules.
Slide 20
-Axial and Coronal FLAIR images (top) show multiple
hyperintense subcortical foci within the frontoparietal lobes
consistent with tubers. -Axial T2WI and T1 IR images (bottom)
demonstrate multiple subependymal nodules (arrows) and abnormal
subcortical and periatrial white matter signal consistent with
tubers (yellow arrows).
Slide 21
Coronal and axial T2WI demonstrate diffuse atrophy and
decreased signal intensity throughout the left temporal lobe
consistent with a calcified hamartomatous left temporal lobe.
Slide 22
T1WI T1+Gd FLAIR -Multisequence brain MRI demonstrates an
enhancing subpendymal mass within the right foramen of Monro
(arrow), with surrounding abnormal hyperintense FLAIR signal,
consistent with SEGA.
Slide 23
Also known as encephalotrigeminal angiomatosis. Clinically
patients demonstrate: Port wine stain and over growth of soft
tissue Seizures Mental deficiency Imaging findings include: Pial
angiomatosis and leptomeningeal enhancement Parenchymal volume loss
and atrophy Ipsilateral choroid plexus enlargement Gyriform
cortical calcifications
Slide 24
Axial T1W images post contrast demonstrate abnormal
leptomeningeal enhancement throughout the right hemisphere and
abnormal right facial/periorbital soft tissue enhancement (arrow)
consistent with likely port wine stain and pial angiomatosis.
Slide 25
Axial and coronal T1W post contrast images (left & center)
and Axial T2WI (right) demonstrate ipsilateral choroid plexus
enlargement (arrows) and right hemispheric atrophy.
Slide 26
Multisystem neurocutaneous disorder characterized by: CNS and
Retinal hemangioblastomas Hemangioblastoma and one: Renal,
pancreatic, hepatic, epididymal cyst Pheochromocytoma Renal cancer
Conditions associated with VHL include Angiomatosis
Hemangioblastomas Pheochromocytoma Renal cell carcinoma Pancreatic
cysts Endolymphatic sac tumor Bilateral papillary cystadenomas of
the epididymis or broad ligament of the uterus.
Slide 27
Axial T1(left), Axial T2 (center) & Axial T1W with Gd
images show circumscribed cystic lesion in the right cerebellum
with a peripheral solid enhancing nodule (arrow). This lesion was
resected and proven to be hemangioblastoma.
Slide 28
Axial head CT images in bone (left) & brain (right)
windows, show extensive bone erosion and the "moth-eaten" petrous
bone secondary endolymphatic sac tumor (ELST). Tissue sampling
confirmed the diagnosis.
Slide 29
Axial T1 pre and post contrast (top), Axial FLAIR, T2WI &
DWI (bottom) images demonstrate heterogeneous signal and
enhancement in the noncystic components of the left
cerebellopontine angle mass, without restricted diffusion, proven
to be ELST.
Slide 30
Rare multi system autosomal recessive neurocutaneous disorder.
Includes both ocular telangiectasia cerebellar ataxia Symptoms:
Cerebellar ataxia - progressive and present in all cases
Oculo-mucocutaneous telangiectasias Greater susceptibility to types
of infection (partial combined immunodeficiency) and neoplasms
Differential Diagnosis : Diffuse cerebellar atrophy Normal aging
EtOH Drugs (e.g phenytoin) Multisystem Atrophy Friedriech Ataxia
Paraneoplastic Degeneration Olivopontocerebellar Atrophy
Neuroimaging Findings There is cerebellar volume loss, compensatory
enlargement of the 4 th ventricle. Hemorrhages may be evident due
to telangiectatic vessel rupture.
Slide 31
Axial GRE images (top) show innumerable punctate foci of
susceptibility artifact in the bilateral cerebral hemispheres,
consistent with petechial hemorrhages. Axial T2W images (bottom)
show scattered hyperintense T2 weighted lesions (arrows) in the
frontoparietal subcortical white matter.
Slide 32
Coronal FLAIR images (top), demonstrate multiple abnormal long
TR subcortical white matter lesions. Sagittal T1WI (bottom left)
shows significant cerebellar atrophy and Axial DWI (bottom right),
demonstrates lack of restricted diffusion in the white matter
lesions.
Slide 33
Basal Cell Nevus Syndrome lesions of mandible and maxilla
resembling odontogenic keratocysts extensive calcification of falx
cerebri frontal and parietal bossing medulloblastoma PHACES
Syndrome posterior fossa malformations, often unilateral cerebellar
hypoplasia cortical dysplasia vascular abnormalities eye
abnormalities Neurocutaneous Melanosis giant or multiple benign
and/or malignant lesions of the central nervous system
leptomeningeal melanosis and melanoma
Slide 34
The phakomatoses are a collection of neurocutaneous disorders
which frequently involve multiple organ systems and tissues. In
radiology, it is important to understand the spectrum of findings
in these diseases as it may pertain to the patient's diagnosis,
prognosis, symptoms, and/or treatment.
Slide 35
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Correlation of Imaging findings with the Presence of
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