Correct!
2. The lesion is non-specific, and an origin from either the pleura or subpleural lung remains possible
While hamartoma remains a potential consideration, the CT features typical of pulmonary hamartoma- intralesional fat and / or chondroid [“popcorn”] calcification- are not present. The lesion is indeterminate as regards aggressive potential. While no features typical of a benign disorder, such as calcification, are visible, the lesion does not show overtly aggressive features, such as gross spiculation, chest wall invasion [in particular, rib destruction], or cavitation. The lesion does not show central necrosis- no central low attenuation is visible within the lesion. The mass could be neural in origin, perhaps arising from the posterior mediastinum- the location raises this possibility. However, one particularly characteristic feature of a lesion arising from a nerve- widening / remodeling of the neural foramen- is not present in this case. The coronal image (Figure 2B) shows sparing of the neural foramen particularly well. Therefore, the best answer among the choices above is “2” The lesion exhibits extensive contact with the chest wall, which raises the possibility of an origin from the pleura, although large subpleural lung lesions may occasionally also appear similarly. Because an origin from either the pleura or chest wall was considered for this lesion, the patient underwent thoracic MRI (Figures 3A-D).
Figure 3: Thoracic MRI prior to (A= axial, B= sagittal) and following (C= axial, D= sagittal) intravenous contrast administration shows that the lesion displays intermediate signal intensity prior to contrast administration, and intense, somewhat peripheral enhancement following contrast administration. The mass contacts the posterior mediastinum and medial posterior pleura, but does not widen or remodel the adjacent neural foramen.
Which of the following choices below regarding the MR appearance of the lesion is accurate?