Gross Anatomy USMLE Step 1 Practice Question
A 65-year-old man with a mediastinal mass presents with facial plethora and neck vein distension. Vital signs show BP 158/92 mmHg, HR 88/min, RR 16/min, and normal oxygen saturation. CT angiography demonstrates superior vena cava obstruction with marked enlargement of a venous channel that arches over the right lung root before draining into the SVC. Chest X-ray shows no pleural effusion. Which of the following vessels is enlarged?
Answer choices
- AThoracic duct
- BAzygos veinCorrect answer
- CInternal thoracic artery
- DHemiazygos vein
- ELeft brachiocephalic vein
- FAccessory hemiazygos vein
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