Neurofibromatosis Type 1

  • Etiology: hamartomatous disorder involving ectoderm and mesoderm
  • Imaging:
    — Orbit: bilateral optic nerve gliomas
    — Skull: macrocephaly, dysplasia of greater wing of sphenoid
    — Brain: brainstem glioma, focal areas of signal intensity (FASI) – T2 hyperintense foci in cerebellar peduncle, brainstem, thalamus, globus pallidus and subcortical white matter
    — Spine: dural ectasia, enlarged neuroforamina, kyphoscoliosis from neurofibromas, pseudoarthrosis
    — Bones: pseudoarthrosis, anterior bowing of long bones, inferior rib notching (ribbon ribs), tibial dysplasia, non-ossifying fibromas around knees
    — GI: polyps (myenteric plexiform neurofibromas), GIST tumors
    — GU: pheochromocytoma
    — Vascular: Moya Moya syndrome, aneurysms, mid aortic syndrome, renal artery stenosis
    — Throughout body: plexiform neurofibromas, macrodystrophia lipomatosa
  • Complications: 5-10% of neurofibromas degenerate into malignant peripheral nerve sheath tumors
  • Clinical: for diagnosis of neurofibromatosis type 1 you need at least 2 of the following
    — >6 cafe au lait spots
    — >2 pigmented iris hamartomas
    — axillary or inguinal freckling
    — optic nerve gliomas
    — first degree relative with neurofibromatosis-1
    — dysplasia of greater wing of sphenoid

Cases of 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 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.
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.
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.