Correct!
The enhanced images [Figures 3C and D] show intense, somewhat peripheral, enhancement, indicating that the lesion at least in part consists of solid, vascularized tissue. Only a single lesion is present in the medial left upper thorax- the lesion is therefore not multifocal in nature. While the lesion is closely related to the adjacent thoracic vertebral body, the lesion is not invading this structure- note in Figure 2A that the fat plane [the “white” tissue] between the vertebral body and mass is intact. Similarly, the lesion is in contact with the proximal descending thoracic aorta, but no clear features to suggest that the lesion is actually invading the aorta are present. The right paratracheal lymph nodes, visible in Figure 2A, are normal in size.
The patient subsequently underwent successful percutaneous transthoracic needle biopsy of the left thoracic lesion. The patient did not experience inordinate pain when the lesion was sampled. Histopathological analysis of the tissue retrieved showed collagen bands with “spindle cells” showing a low mitotic rate and low cellularity.
Among the following choices, which of the following is the most likely diagnosis for this patient?