Idiopathic Fibrosing Mediastinitis: A Case Report

Introduction: Fibrosing mediastinitis (FM) is a rare condition that is characterized by the encasement of mediastinal structures. The process can be insidious or rapid. The disease may be idiopathic, autoimmune mediated or related to late complications of histoplasmosis and tuberculosis. The clinical features consist of compression phenomena. The diagnosis is histological by explorative thoracotomy and demands exclusion of malignancy and other mediastinal tumors.

Case Report: We present a case of a 60-year-old man who was referred for evaluation of a pleural effusion with the suspicion of malignancy based on an unclear cytologic analysis at a community hospital one week earlier. The history contained right pulmonary embolism three months ago, newly diagnosed liver cirrhosis and progressive hoarseness. PET CT scan showed no malignant process or other pathology. A diagnostic uniportal thoracoscopic approach was chosen. The histologic evaluation of pleural effusion mediastinal lymph nodes, pleura and right lung wedge resection showed no malignancy. The tests for tuberculosis and histoplasmosis were negative. The patient was dismissed in good clinical status. Three weeks later the patient presented with a recurrent pleural effusion. During explorative thoracotomy large amounts of chylous were evacuated. The inspection and palpation of the mediastinum and paramediastinal structures revealed a massive bulk of fibrotic tissue. Extensive mediastinal pleurolysis, parietal pleurectomy and pulmonary ligament dissection were performed. Palpation of the Vena cava superior showed a massive thrombosis. The pathology confirmed the diagnosis of extensive fibrosing process and excluded malignancy or other pathology. After exclusion of other primary diseases the diagnosis of idiopathic FM was adopted. Therapy with high-dose prednisolone was started. The postoperative course was free of complications and he was dismissed on postoperative day 10. The outpatient control one month later was satisfactory.

Conclusion: This is a rare case of idiopathic fibrosing mediastinitis with fulminant compression of mediastinal structures, involving the thoracic duct, the laryngeal nerve, the pulmonary artery, and the Venae cavae superior and inferior. The diagnosis is challenging as symptoms mimic other pathological entities and present late in the course of the disease. No specific treatment is recommended as most cases have a self-limited course.