Posterior Mediastinal Ancient Schwannoma Mimicking a Cyst

Background: Several types of neurogenic tumors can occur in mediastinum and commonly present as posterior mediastinal mass lesions. Generally they are categorized in to those arising from peripheral nerves or sympathetic ganglia. Schwannoma is the most common neurogenic tumor of this area. Generally they are presented as solid encapsulated lesions and are difficult to miss on radiology. Rarely they can be large enough to undergo cystic degeneration and cause confusion with other cystic mass lesions of the area. Large masses can also cause pressure symptoms and leads to respiratory compromise. Conclusion: Posterior mediastinal schwannomas though usually are benign and asymptomatic but can prove fatal if attain a very large size. It should always be included in the differential diagnosis of posterior mediastinal large cystic masses. Degenerative nuclear atypia associated with ancient schwannoma should not be confused with malignancy. Patient can lead a symptom free life after surgical resection of these tumors.