Primary Tumors of the Middle and Posterior Mediastinum

Abstract

Mediastinal cysts and neurogenic neoplasms are common primary middle and posterior mediastinal masses. Foregut cysts are a relatively frequent cause of a middle mediastinal mass and may progressively enlarge or rarely rupture, while pericardial cysts are infrequent lesions which rarely produce complications or symptoms. Schwannomas and neurofibromas are benign peripheral nerve tumors and are the most common mediastinal neurogenic neoplasms. Malignant tumors of nerve sheath origin are rare. Tumors arising in sympathetic ganglia typically occur in children and young adults and include ganglioneuroma, ganglioneuroblastoma and neuroblastoma. Mediastinal paragangliomas are rare. Lateral thoracic meningocele is the most common cause of a posterior mediastinal mass in a patient with neurofibromatosis.

Neurogenic Tumors of the Mediastinum: A Report of 60 Cases

“…In adults, most of the tumours are described as benign (2,4,12). In our patients, the malignancy rate in adults was 8.5%, which is similar to that of other reports (8,12).…”

“…These previous reports were consistent with our findings that nerve cell tumours comprised the majority in children (69%), and nerve sheath tumours were more common in adults (83%). When all age groups were considered, the schwannomas constituted the largest group with a frequency of 51.6%; other studies report the incidence of schwannomas as between 45% and 60% (2,8). In previous studies, the mediastinal tumours have been benign in most instances, with an overall incidence of malignancy ranging from 3% to 19% (1,4,5).…”

“…In our practice, they comprised 21.2% of all mediastinal tumours in patients from all age groups who had surgical operations for mediastinal masses. Neurogenic tumours are generally grouped into three major catogories: those arising from peripheral nerves (nerve sheath tumours); those arising from autonomic ganglia (nerve cell tumours); and, rarely, those arising from the paraganglionic system (paragangliomas) (8). Nerve sheath tumours are most common in adults, while nerve cell tumours are more common in children (8,9).…”

“…Neurogenic tumours are generally grouped into three major catogories: those arising from peripheral nerves (nerve sheath tumours); those arising from autonomic ganglia (nerve cell tumours); and, rarely, those arising from the paraganglionic system (paragangliomas) (8). Nerve sheath tumours are most common in adults, while nerve cell tumours are more common in children (8,9). These previous reports were consistent with our findings that nerve cell tumours comprised the majority in children (69%), and nerve sheath tumours were more common in adults (83%).…”

Sonographic management of mediastinal syndrome

“…In the presence of mediastinal syndrome, it is important to exclude other reasons for lymph node involvement, particularly infectious conditions (tuberculosis, mycosis, and parasitosis), metastases, inflammatory granulomatous disorders (sarcoidosis and Castleman's disease) and immunological disorders (graft-versus-host disease and systemic lupus erythematosus), Still's disease, rheumatoid arthritis, etc. [1,2]. This requires a diagnosis confirmed by total body spiral CT and biopsy of possible neck lymph nodes, or CTguided biopsy of the mediastinal mass if there are no neck lymph nodes.…”