An Asymptomatic Right Tracheobronchial Mass on Chest Radiograph* Pyng Lee, MD; Cynthia Bin Eng Chee, MD; and Yee Tang Wang, MD (CHEST 2001; 119:1582–1585) A n asymptomatic 20-year-old Indian woman pre- sented to our department with a prominent right tracheobronchial mass detected on a preemploy- ment chest radiograph. She had an uneventful child- hood and did not have any significant medical or surgical history. Clinical examinations of the cardio- vascular and respiratory systems and the abdomen were normal. The chest radiograph showed a right tracheobron- chial mass with deviation of the right paravertebral pleura. The cardiac silhouette was normal, and the gastric bubble was seen below the left hemidia- phragm (Fig 1). Lateral chest radiograph revealed that the mass was behind the trachea and there was an absence of the inferior vena cava (IVC) shadow (Fig 2). CT of the thorax and abdomen showed the azygos vein to be dilated (Fig 3) as a result of absent infrahepatic IVC (Fig 4). The cardiac chambers, lungs, liver, and hepatic veins were normal, and there was no situs inversus. What is the diagnosis? *From the Department of Respiratory Medicine, Tan Tock Seng Hospital, Singapore. Manuscript received March 6, 2000; revision accepted May 8, 2000. Correspondence to: Yee Tang Wang, MD, Department of Respi- ratory Medicine, Tan Tock Seng Hospital, 11 Jalan Tan Tock Seng, Singapore 308433; e-mail: lee_pyng@notes.ttsh.gov.sg Figure 1. Chest radiograph showed a right tracheobronchial mass with normal cardiac silhouette and left-sided gastric bubble. roentgenogram of the month 1582 Roentgenogram of the Month