Sara M. Koenig, MD
Wilson B. Altmeyer, MD
Carlos Bazan III, MD
Maria P. Valencia, MD
• No financial disclosures
• Our purpose is to review the collective radiographic findings of common
individual phakomatoses, focusing on:
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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.
• 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.
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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)
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>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
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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
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.
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.
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.
Axial and coronal T2 FS images demonstrate thickening of the bilateral optic nerves, right
greater than left, consistent with optic pathway gliomas.
T1WI
T2WI
T1 + Gd
T1 + Gd
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.
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.
• 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
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Schwannomas of cranial nerves and spinal
nerve roots
Meningiomas
Ependymomas
- Most commonly intramedullary spinal cord lesions
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.
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.
T1WI
T2WI
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Axial T1WI and T2WI FS
images (top) show an iso to
hyperintense intramedullary
superior cervical cord lesion
consistent with ependymoma
(white arrow).
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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
T2WI
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.
• 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:
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Multiple partially calcified subependymal nodules
Subcortical tubers
Radial migration of white matter lines
Subepependymal giant cell astrocytoma (SEGA)
White matter cyst-like lesions
• 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
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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
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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
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.
- 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).
Coronal and axial T2WI demonstrate diffuse atrophy and decreased
signal intensity throughout the left temporal lobe consistent with a calcified
hamartomatous left temporal lobe.
- Multisequence brain MRI
demonstrates an enhancing
subpendymal mass within the
right foramen of Monro
(arrow), with surrounding
abnormal hyperintense FLAIR
signal, consistent with SEGA.
T1WI
FLAIR
T1+Gd
T1 + Gd
• Also known as encephalotrigeminal angiomatosis.
• Clinically patient’s demonstrate:
• Port wine stain and over growth of soft tissue
• Seizures
• Mental deficiency
• Imaging findings include:
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Pial angiomatosis and leptomeningeal enhancement
Parenchymal volume loss and atrophy
Ipsilateral choroid plexus enlargement
Gyriform cortical calcifications
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.
Axial and coronal T1W post contrast images (left & center) and Axial
T2WI (right) demonstrate ipsilateral choroid plexus enlargement (arrows)
and right hemispheric atrophy.
• 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
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Angiomatosis
Hemangioblastomas
Pheochromocytoma
Renal cell carcinoma
Pancreatic cysts
Endolymphatic sac tumor
• Bilateral papillary cystadenomas of the epididymis or broad ligament of the uterus.
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.
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.
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.
• 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
Neuroimaging Findings
• Normal aging
• EtOH
• There is cerebellar volume loss,
• Drugs (e.g phenytoin)
compensatory enlargement of the 4th
• Multisystem Atrophy
ventricle.
• Friedriech Ataxia
• Hemorrhages may be evident due to
• Paraneoplastic Degeneration
telangiectatic vessel rupture.
• Olivopontocerebellar Atrophy
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.
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.
• Basal Cell Nevus Syndrome
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lesions of mandible and maxilla resembling odontogenic keratocysts
extensive calcification of falx cerebri
frontal and parietal bossing
medulloblastoma
• PHACES Syndrome
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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
• 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.
• Aoki S, Barkovich JA, Mishimura K, et al. Neurofibromatosis types 1
and 2: Cranial MR findings. Radiology 1989: 172: 527-534
• Baron Y, Barkovich AJ. MR imaging of tuberous sclerosis in neonates
and young infants. AJNR Am J Neuroradiol 1999: 20: 907-916
• Kornreich L, Blaser S, Schwarz M, et al. Optic Pathway Glioma:
Correlation of Imaging findings with the Presence of
Neurofibromatosis. AJNR Am J Neuroradiol 2001: 22: 1963-1969
• Muniz, IS. Neurofibromatosis Type 1. In: Martinez-Leon MI, Ceres-Ruiz
L, Gutierrez JE, eds. Learning Pediatric Imaging. New York: Springer;
2011: 44-45
• Nozaki T, Nosaka S, Miyazaki O. Syndromes Associated with Vascular
Tumors and Malformations: A Pictorial Review. Radiographics 2013:
33: 175-195