1. A 28-Year-Old Man With a Mediastinal Mass
Gregory N. Matwiyoff, MD, David A. Bradshaw, MD, FCCP, Kurt H. Hildebrandt, MD, Jennifer F. Campenot, MD, Joelle M. Coletta, MD, Walter J. Coyle, MD 
CHEST 
Volume 134, Issue 3, Pages (September 2008)
DOI: /chest
Copyright © 2008 The American College of Chest Physicians Terms and Conditions

2. Figure 1
Contrast-enhanced chest CT scan shows an oval, well-circumscribed, homogeneous opacity anterior to the seventh thoracic vertebrae. The nonenhancing opacity (arrow) is surrounded by the esophagus, descending aorta, and azygous vein.
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Copyright © 2008 The American College of Chest Physicians Terms and Conditions

3. Figure 2
Postcontrast, reformatted coronal CT demonstrates a nonenhancing thin, tubular structure (solid arrows) coursing into the inferior border of the mediastinal lesion (boxed arrow).
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Copyright © 2008 The American College of Chest Physicians Terms and Conditions

4. Figure 3
Sagittal T1-weighted, fat saturation, post-gadolinium MRI image demonstrates a thin tubular structure (small arrows) communicating with the smooth-walled homogeneous mediastinal lesion (large arrow).
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Copyright © 2008 The American College of Chest Physicians Terms and Conditions

5. Figure 4
Left: Photomicrograph of the cyst wall overlying a stroma of fat and connective tissue (hematoxylin-eosin, original × 4). Right: Photomicrograph of immunohistochemical stains for the endothelial markers CD31 (top left), CD34 (top right), and factor VIII-related antigen (bottom). Note the flat monolayer of cells lining the cyst (original × 40).
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Copyright © 2008 The American College of Chest Physicians Terms and Conditions