Posterior Mediastinal Thymus: Case Report and Literature Review

Background: The incidence of aberrant thymus in the posterior mediastinum is very uncommon. It is difficult to exclude malignancy before surgical procedure.
Case Presentation: In a six-month-old male coughing for two weeks prior to admission a posterior mediastinal mass was found incidentally by chest roentgenogram. Thoracotomy was performed. Histologic study revealed normal thymic tissue.
Conclusion: When a mass located in the posterior mediastinum, ectopic thymus should be included in differential diagnosis. Imaging techniques may spare thoracotomy. Ectopic thymus has a benign clinical course, and surgical resection is not recommended.