Primary mediastinal diffuse large cell lymphoma initially presented with pericardial infiltration.

A 33-year-old Japanese woman visited our hospital with progressive dyspnea. A chest roentgenogram and a chest computed tomogram revealed a mediastinal tumor and pericardial effusion. Ultrasound cardiography revealed the existence of cardiac tamponade. She was successfully treated with emergency pericardial drainage, thoracocentesis and chemotherapy. The histological diagnosis of diffuse large B cell lymphoma was established with the tumor specimen obtained by transcutaneous fine needle aspiration biopsy and through immunohistochemical analysis. This is a rare case of primary mediastinal diffuse large cell lymphoma with initial presentation of a symptom related to pericardial effusion.