Pediatric Neurofibromatosis Type 1

  • Etiology: Phakamatosis, hamartomatous disorder involving ectoderm and mesoderm
  • Imaging MRI Orbit:
    — Bilateral optic nerve gliomas
  • Imaging Skull:
    — Macrocephaly
    — Dysplasia of greater wing of sphenoid
  • Imaging MRI Brain Focal areas of signal intensity (FASI):
    — T2 hyperintense foci in peduncles or deep gray of cerebellum and brainstem (especially pons) and basal ganglia (especially globus pallidus) and supratentorial white matter
    — More central than tuberous sclerosis which is more peripheral
    — May decrease with age especially in cerebellum
    — Rarely enlarge in adulthood
    — If enlarges or enhances after adolescence consider neoplasm and short term followup
    — If growing than usually low grade pilocytic astrocytoma
  • Imaging MRI Brainstem:
    — Brainstem glioma
  • Imaging MRI Spine:
    — Dural ectasia manifesting as scalloping of posterior aspect of vertebral body and widening of spinal canal
    — Enlarged neuroforamina due to nerve sheath tumors
    — Kyphoscoliosis from neurofibromas
    — Pseudoarthrosis
  • Imaging Bones:
    — Pseudoarthrosis
    — Anterior bowing of long bones
    — Inferior rib notching (ribbon ribs)
    — Tibial dysplasia
    — Multiple non-ossifying fibromas around knees
  • Imaging Gastrointestinal:
    — 10-25% of neurofibromatosis Type-1 patients have gastrointestinal involvement
    — Neurofibroma is most common gastrointestinal tract neoplasm in the form of myenteric plexiform neurofibromas which appear as polyps that can cause gastrointestinal bleeding and intussusception and obstruction and volvulus
    — Can have GIST tumors
  • Imaging Genitourinary:
    — Pheochromocytoma
  • Imaging Vascular:
    — Moya Moya syndrome
    — Aneurysms
    — Mid aortic syndrome
    — Renal artery stenosis
  • Imaging Throughout Body:
    — Plexiform neurofibromas
    — Macrodystrophia lipomatosa
  • DDX:
  • Complications: 5-10% of neurofibromas degenerate into malignant peripheral nerve sheath tumors
  • Treatment:
  • Clinical: For diagnosis of neurofibromatosis type 1 you need at least 2 of the following:
    — Greater than 6 cafe au lait spots
    — Greater than 2 pigmented iris hamartomas (Lisch nodules)
    — Greater than or equal to 2 neurofibromas or greater than or equal to 1 plexiform neurofibroma
    — Axillary or inguinal freckling
    — Optic nerve gliomas
    — First degree relative with neurofibromatosis type 1
    — Dysplasia of greater wing of sphenoid or pseudoarthrosis of a long bone
  • Clinical: Opthalmologic findings of choroidal hamartomas and Lisch nodules and optic disc swelling due to optic nerve gliomas and buphthalmos

Radiology Cases of Neurofibromatosis Type 1

Radiology Cases of Plexiform Neurofibroma in Neurofibromatosis Type 1

CXR and MRI of neurofibromatosis type I
CXR shows a posterior mediastinal mass. Coronal and sagittal T1 MRI without contrast of the thoracic spine shows dural ectasia.
CXR and CT of plexiform neurofibroma in neurofibromatois type 1
CXR PA shows a large soft tissue mass in the apex of the right lung which causes thinning of the right 1st-5th ribs posteriorly. CT without contrast of the chest shows multiple small nodules throughout the soft tissues of the chest wall.
Tomogram of plexiform neurofibroma causing painful scoliosis
Coronal conventional tomogram of the thoracic spine shows a soft tissue mass in the apex of the right lung causing scalloping of the right side of the upper thoracic vertebral bodies and a scoliosis convex left.

Radiology Cases of Malignant Peripheral Nerve Sheath Tumor in Neurofibromatosis Type 1

CXR and CT of malignant peripheral nerve sheath tumor in neurofibromatosis type 1
CXR PA and lateral shows a right apical thoracic mass with associated rib thinning that had rapidly increased in size in a short interval. Axial CT without contrast of the chest better defined the right apical mass and demonstrated multiple serpiginous nodules in the soft tissues of the right anterior chest wall.

Radiology Cases of Moya Moya Syndrome in Neurofibromatosis Type 1

MRA of Moya Moya syndrome in neurofibromatosis type I
AP view of a 3D maximum intensity projection of an MRA of the neck with contrast (above) and AP (below left) and inferior (below right) views of a 3D maximum intensity projection of an MRA of the brain without contrast shows diffuse hypoplasia of the left internal carotid artery. There is stenosis and occlusion of the cavernous and supraclinoid segments of the left internal carotid artery and then there is a thin left M1 segment without evidence of collaterals in the basal ganglia. Additionally, aneurysms are noted in the left A1 and A2 segments.

Radiology Cases of Mid Aortic Syndrome Causing Bilateral Renal Artery Stenosis in Neurofibromatosis Type 1

CT angiogram and spectral doppler US of bilateral renal artery stenosis in a patient with neurofibromatosis Type 1
3D reconstruction of a CT angiogram with contrast of the chest and abdomen (left) shows diffuse moderate narrowing of the mid aorta and marked narrowing of the origins of the renal arteries bilaterally. Spectral doppler US of the renal arteries (right) shows parvus tardis waveforms within them bilaterally.
US and angiogram of bilateral renal artery stenosis due to midaortic syndrome in a patient with Neurofibromatosis Type I
Spectral doppler US of the kidneys (above) shows tardus parvus waveforms in the renal arteries bilaterally. AP image from an abdominal angiogram (below) shows bilateral stenosis of the renal arteries at their origins and progressive narrowing of the mid abdominal aorta centered near the renal artery origins with sparing of the aortic bifurcation.
CT of midaortic syndrome
Axial CT with contrast of the abdomen shows the aorta to have a normal caliber in the upper abdomen (above left) and a markedly decreased caliber in the mid-abdomen (above right). Sagittal CT (below left) shows a long length of progressive narrowing of the mid-abdominal aorta. 3D CT (below right) shows moderate stenosis of the abdominal aorta from T12 to L2 and severe ostial stenosis of the celiac artery and superior mesenteric artery and the bilateral renal arteries. The inferior mesenteric artery is enlarged with robust collaterals to the celiac and superior mesenteric circulations. There is sparing of the aortic bifurcation and iliac arteries.

Radiology Cases of Bilateral Renal Artery Stenosis Due to Midaortic Syndrome in Neurofibromatosis Type 1

CT angiogram and spectral doppler US of bilateral renal artery stenosis in a patient with neurofibromatosis Type 1
3D reconstruction of a CT angiogram with contrast of the chest and abdomen (left) shows diffuse moderate narrowing of the mid aorta and marked narrowing of the origins of the renal arteries bilaterally. Spectral doppler US of the renal arteries (right) shows parvus tardis waveforms within them bilaterally.
US and angiogram of bilateral renal artery stenosis due to midaortic syndrome in a patient with Neurofibromatosis Type I
Spectral doppler US of the kidneys (above) shows tardus parvus waveforms in the renal arteries bilaterally. AP image from an abdominal angiogram (below) shows bilateral stenosis of the renal arteries at their origins and progressive narrowing of the mid abdominal aorta centered near the renal artery origins with sparing of the aortic bifurcation.

Radiology Cases of Celiac Artery and Superior Mesenteric Artery and Bilateral Renal Artery Stenosis Due to Midaortic Syndrome in Neurofibromatosis Type 1

CT of midaortic syndrome
Axial CT with contrast of the abdomen shows the aorta to have a normal caliber in the upper abdomen (above left) and a markedly decreased caliber in the mid-abdomen (above right). Sagittal CT (below left) shows a long length of progressive narrowing of the mid-abdominal aorta. 3D CT (below right) shows moderate stenosis of the abdominal aorta from T12 to L2 and severe ostial stenosis of the celiac artery and superior mesenteric artery and the bilateral renal arteries. The inferior mesenteric artery is enlarged with robust collaterals to the celiac and superior mesenteric circulations. There is sparing of the aortic bifurcation and iliac arteries.

Radiology Cases of Optic Pathway Glioma in Neurofibromatosis Type 1

MRI of optic pathway gliomas in neurofibromatosis type I
Axial (left) and coronal T1 MRI with contrast of the orbits shows marked thickening of the optic nerves bilaterally.
MRI of macrophtalmia and optic pathway glioma in neurofibromatosis type I
Axial (above) and coronal (below) T2 MRI without contrast of the brain shows the left globe is larger than the right globe. The optic nerves bilaterally are thickened and tortuous.

Radiology Cases of Multiple Non Ossifying Fibromas in Jaffe Campanacci Syndrome in Neurofibromatosis Type I

Radiograph of multiple non ossifying fibromas in Jaffe Campanacci Syndrome
AP and lateral radiographs of the knee show multiple lucent lesions with thin sclerotic margins in the metaphysis of the femur, tibia and fibula.

Clinical Cases of Neurofibromatosis Type 1

Clinical image of neurofibromatosis type 1 with chest wall and arm plexiform neurofibromas
Clinical image shows extensive, large soft tissue masses involving the right arm and chest wall.

Surgery Cases of Neurofibromatosis Type 1

Surgery image of malignant peripheral nerve sheath tumor
Surgical image through a right thoracotomy shows a large mass originating in the apex of the right chest. Normal lung can be seen in the upper right corner of the incision.

Histopathology Cases of Neurofibromatosis Type 1

Histopathology image of malignant schwannoma within a plexiform neurofibroma
Histopathological image H&E stained section shows short fascicles comprised of spindle-shaped cells with a moderate amount of pleomorphism and scattered mitoses, with malignancy being defined by the number of mitotic figures which can be counted. Overall this was felt to represent a malignant schwannoma within a plexiform neurofibroma.