Correct!
5. Thymic malignancy
The chest radiographic characteristics of the lesion are consistent with an extraparenchymal process- the lesion is fairly smoothly marginated, with a broad contact with the mediastinal pleura and mediastinum, and if one “extrapolates” into a circle the right lateral convex margin of the lesion, the center of the extrapolated circle projects within the mediastinum. Pleural lesions, however, because they are also extraparenchymal, may appear similar, and therefore, a solitary fibrous tumor of the pleura originating from the mediastinal pleural surface is possible. The lesion overlies the thoracic aortic arch on the lateral study, placing it in the middle mediastinum- therefore, lymphoma and aneurysm are both reasonable considerations. While neurogenic tumors most commonly are found in the posterior mediastinum, such a lesion arising along the course of the vagus nerve could present in this fashion, and therefore choice 3. Neurogenic tumor- remains a possibility. Thymic lesions arise from the anterior mediastinum and therefore a thymic malignancy is the least likely among the considerations presented.
The patient underwent thoracic CT (Figure 5) for further characterization of the chest radiographic findings.
Figure 5. Axial thoracic CT images displayed in soft tissue windows prior to (A-C) and following (D-F) intravenous contrast administration. Lower left: movie of soft tissue windows prior to intravenous contrast. Lower right: movie of soft tissue windows after intravenous contrast.
Which of the following statements regarding this CT examination is most accurate? (Click on the correct answer to move to next panel)