Neurogenic tumors are the cause of approximately 90% of posterior mediastinal masses. They can be subdivided into three groups by their location and involvement of peripheral nerves or sympathetic chain 1-3.
Peripheral nerve sheath tumors and paragangliomas are far more common in adults while the sympathetic ganglia tumors are more common in children.
Peripheral nerve sheath tumors
Peripheral nerve sheath tumors (PNSTs) manifest as round paravertebral masses that span one or two vertebral bodies. They are homogenous, soft-tissue attenuation masses at CT and the commonest cause of posterior mediastinal and paravertebral masses. They may cause widening of the neural foramen and thickening of the adjacent posterior rib.
- hybrid nerve sheath tumor
- malignant peripheral nerve sheath tumor
Schwannoma and neurofibroma are by far the most common type of neurogenic tumor in adults.
Sympathetic ganglia tumors
These tumors tend to present as elongated paraspinal masses that span multiple vertebral levels. Intra-tumoral calcification is common 1-3.
- neuroblastoma - young children
- ganglioneuroblastoma - older children
- ganglioneuroma - children and adults
Neuroblastoma and ganglioneuroblastoma are most commonly seen in children and in a child, they comprise the most common neurogenic tumor.
These neuroendocrine tumors are similar histologically to pheochromocytoma and can be functioning or non-functioning 1-2. They are found arising from the base of the skull to the pelvis and are discussed further in the article on paragangliomas.
- 1. Reed JC, Hallet KK, Feigin DS. Neural tumors of the thorax: subject review from the AFIP. Radiology. 1978;126 (1): 9-17. doi:10.1148/126.1.9 - Pubmed citation
- 2. Kreel L. Goitre and neurofibroma. Postgrad Med J. 1986;62 (728): 463-5. doi:10.1136/pgmj.62.728.463 - Free text at pubmed - Pubmed citation
- 3. Nakazono T, White CS, Yamasaki F, Yamaguchi K, Egashira R, Irie H, Kudo S. MRI findings of mediastinal neurogenic tumors. AJR. American journal of roentgenology. 197 (4): W643-52. doi:10.2214/AJR.10.6119 - Pubmed