Invasive thymoma presenting as classic superior vena cava syndrome: a case of venous spread metastasis.

The approach to an intrinsic cause of superior vena cava syndrome (SVCS) is usually difficult but rewarding. We report a case of a middle-aged man who presented with progressive oedema of the upper half of the body, dyspnoea, cough and weight loss for a 1-year duration. He was a non-smoker without prior hospitalisation. Chest radiography showed right-sided pleural effusion with an apparent normal superior mediastinum. Contrast-enhanced CT of the chest revealed a right atrial mass extending and completely obliterating to superior vena cava. The differentials were tuberculosis, invasive fungal granuloma, sarcoidosis, primary vasculitis, chronic venous thrombosis, cardiac sarcoma/lymphoma and metastatic thyroid tumour or thymoma. He underwent transvenous (femoral approach) biopsy of the mass and then cardiothoracic surgery after haemodynamic instability. Pathology showed invasive thymoma type B3. This case highlights the approach to an intrinsic cause of SVCS, a complication of the transvenous approach, and importantly a noble finding of venous spread metastasis.