Discussion
Diagnosis With Brief Discussion
- Diagnosis
- Neurofibromatosis type 1
- Radiologic Findings
- Fig 1. Chest PA shows bilateral mediastinal bulging shadows.
Fig 2-5. On chest CT, there are multiple conglomerated soft tissue lesions in the mediastinum, supraclavicular fossae, axillae, r and the upper abdomen. The masses show homogeneous low attenuation without significant enhancement. Some masses show encasement of surrounding structures without mass effect or invasion. Also, there are other multiple nodules and low attenuated lesions in the subcutaneous fat layer and the muscles of the chest wall.
- Brief Review
- Neurofibromatosis type 1 (NF1), or von Recklinghausen disease, is the most common of the phakomatoses and has a localized or systemic manifestations involving the thorax, abdomen, pelvis, and extremities.
Typical CT findings in patients with NF1 include small, well-defined subcutaneous neurofibromas, focal thoracic scoliosis, posterior vertebral scalloping, enlarged neural foramina, and characteristic rib abnormalities due to bone dysplasia or erosion from adjacent neurofibromas in the thorax. NF1 in the abdomen frequently involves the retroperitoneal, mesenteric, and paraspinal areas. The typical peripheral manifestations of NF1 include limb hemihypertrophy, pseudarthrosis, peripheral nerve neurofibromas, and subcutaneous common and plexiform neurofibromas.
Differential diagnosis for multiple mediastinal lymphadenopathies include sarcoidosis, tuberculosis, lymphoma, metastasis, and so on. Up to 73% of cases of masses in NF1 demonstrate characteristic low attenuation, but they may show soft-tissue attenuation at contrast enhanced CT. Factors responsible for this low attenuation include cystic degeneration, xanthomatous features, confluent areas of hypocellularity, and lipid-rich Schwann cells.
- References
- 1. Fortman BJ, Kuszyk BS, Urban BA, Fishman EK. Neurofibromatosis Type 1: A Diagnostic Mimicker at CT. RadioGraphics 2001; 21:601-612.
- Keywords
- mediastinum, chest wall,