Neurofibromatosis 1
Criteria for the diagnosis of NF1 are met in an individual if 2 or more of the following signs are found:
- Six or more café au lait macules larger than 5 mm in the greatest diameter in prepubertal children and larger than 1.5 cm in postpubertal individuals
- Two or more neurofibromas of any type or one plexiform neurofibroma
- Multiple freckles (Crowe sign) in the axillary or inguinal region
- A distinctive osseous lesion, such as sphenoid dysplasia or thinning of long bone cortex, with or without pseudoarthrosis
- Optic glioma
- Two or more iris hamartomas (Lisch nodules) seen on slitlamp or biomicroscopy examination
- A first-degree relative (parent, sibling, offspring) with NF1, as diagnosed by using the criteria above
Radiologic Features:
- Kyphoscoliosis is the most common spinal roentgen sign, occurring in 50% patients. The kyphoscoliosis is classically acutely angular and is short segmented usually affecting the lower thoracic spine.
- Scalloping of the posterior surface of the vertebral bodies is characteristic.
- An eccentric paraspinal mass is often seen on AP thoracic or PA chest radiograph.
- Intrathoracic meningoceles represent a common cause for the presence of a posterior mediastinal mass.Most meningocele occur laterally and on the right side.
- Unilateral agenesis or hypoplasia affecting the sphenoid portion of the posterior wall of the orbit, creating a bare orbit, is characteristic.
- Scalloping irregularities of the ribs create the twistedc ribbon appearance.
- Pseudoarthrosis of tibia occurs in 50% of cases.
- Multiple large bilateral non-ossifying fibroma have been documented to occur in association.
- Focal gigantism(local overgrowth or hypertrophy of both skeletal and soft tissue structures), usually of the lower extremties, is perhaps the most bizarre and fascinating roentgen sign.