5 °C. He denied purulent sputum, hemoptysis and arthronalgia. Unfortunately, the cough and shortness of breath of the patient had progressively worsened over time. Chest examination revealed absent breath sounds on the lower two thirds of the left hemithorax and a dull percussion note. No detectable peripheral lymphadenopathy was found. Laboratory results included normal creatinine, blood urea nitrogen, and serum electrolyte; lactate dehydrogenase

(LDH), 179 U/L; alanine aminotransferase (ALT), 30U/L; aspartate aminotransferase (AST), this website 25 U/L; total protein (TP), 66.3 g/L; leukocyte count, 10.3 × 109/L; hemoglobin, 16.7 g/dl; platelet count, 233 × 109/L. A peripheral blood smear examination revealed no abnormal lymphoid cells. Serum test results I-BET-762 in vitro were negative for carcinoembryonic

antigen (CEA), squamous cell carcinoma associated antigen (SCC), hepatitis B virus (HBV), human immunodeficiency virus (HIV), hepatitis C virus (HCV), Schaudinn’s bacillus. We did not carry out human herpesvirus 8 (HHV8) test in our center. Also serum test showed erythrocyte sedimentation rate (ESR), 8 mm/h; and C-reactive protein (CRP), 43.6 mg/L. Sputum cultures were negative for bacteria, fungus, and Mycobacterium tuberculosis. Chest X-ray demonstrates a large anterior mediastinal mass and a left pleural effusion with a light contralateral shift of the trachea and mediastinum (Fig. 1). Chest computed tomography (CT) showed an anterior and middle mediastinal mass with a light contralateral shift of the trachea, pleural thickening of the left hemithorax, and left-sided pleural effusion (Fig. 2). Chest ultrasonography revealed massive left pleural effusion. Echocardiography showed little pericardial effusion. And ultrasonography of superficial lymph node showed lymphadenopathy in bilateral axillary region (left 21.1 × 11.4 mm; right 15.4 × 4.4 mm), from bilateral cervical region, (left, 18.7 × 17.1 mm; right 12 × 5.2 mm), and bilateral inguinal region (left 16 × 4.8 mm; right 11.3 × 9.3 mm), but not in retroperitoneal region. Thoracentesis were performed and revealed exudate with lactate dehydrogenase level of 721 U/L, ADA value of 25 U/L, and

TP 15.3 g/L. Pleural fluid were grossly bloody and the routine examination of pleural fluid showed leukocytes 5 × 109/L (55% percent multinucleated cells, 54% percent mononuclear cells). The cytologic examination of the effusion smears revealed massive lymphocytes, a small amount of mesothelial cells, and partly abnormal cells (tumor cell?). Pleural fluid cultures were negative for M. tuberculosis. Then the medical thoracoscopy was performed under local anesthesia, cardiovascular and respiratory monitoring, in the endoscopy suite by experienced operator. The inspection of the pleural by a direct vision optic revealed massive bloody pleural fluid in the pleural cavity, and widely membrane hyperemia with lots of small white apophysis involving the parietal pleura (Fig. 3).