Abstract
A healthy young man presented with cardiac tamponade. He underwent pericardial window and biopsy revealed chronic inflammation. Two years later, he presented with respiratory failure. CT of the thorax revealed prominent anterior mediastinal mass abutting the brachiocephalic vein consistent with thymic tumour. Open lung biopsy revealed metastatic intermediate-grade neuroendocrine carcinoma with lymphangitic spread. Corticosteroids were started for palliation. He made a remarkable improvement clinically and radiologically in 2 days of starting steroids. Thymic neuroendocrine carcinomas are very aggressive and the clinical presentation is varied and atypical. Our patient presented with cardiac tamponade. Malignancy should be considered in the differential diagnosis of unexplained cardiac tamponade. The other important point illustrated by our case is the dramatic response to the steroids. Treatment of metastases of any tumour of thymic origin with steroids could be an option when more conventional therapeutic methods fail.