A large, lobulated 4.4 X 7.9 (axial) X 4.8 (cc) cm T1 hypointense, heterogenously T2 hyperintense, enhancing, pleurally based left paraspinal mass posteromedially is demonstrated at the level of T4 and T5. There are areas of non-enhancement/cystic change within the mass, likely representing necrosis. Foci of susceptibility change within the mass are in keeping with calcification seen on CT. The mass abuts but doesn't involve of the left T4/5 intervertebral foramen.
No overt rib destruction.
There is minor pressure erosion (saucerisation) of the adjacent ribs and thoracic vertebra.
This is not of pulmonary origin.
A focal right paracentral T5/6 disc extrusion is present, which causes anterior indentation/effacement of the thecal sac. A smaller left paracentral left T6/7 disc protrusion also causes minor thecal sac indentation.
No other significant spinal canal, lateral recess or foraminal stenosis.Marrow signal is normal. Vertebral alignment is unremarkable. No epidural mass or collection.Imaged lungs and other paraspinal structures are unremarkable, other than for dependent pulmonary atelectatic change.
Conclusion
Left T4/5 level pleurally-based mass as described, indeterminate.
This is a long-standing lesion causing pressure remodelling of the adjacent vertebrae and ribs without invasion, remaining entirely extra-osseous.
A solitary fibrous tumour is suspected.
A chondral lesion or neural lesion are thought less likely.