This is a 53-years old man who had an incidentally discovered prevascular space mass. PET/CT showed no other lesion.
He came for a biopsy. The only approach was through the lung, so I chose a trans-sternal approach directed along the long axis of the lesion through the lung using a 20G coaxial biopsy gun. A trans-sternal approach is safe and this can be done without sedation, by just infiltrating the periosteum of the anterior cortex. The bone is thin enough that a light tap of the mallet is sufficient to push the needle through. The only disadvantage is the inability to maneuver the needle if needed.
The diagnosis was thymoma WHO B type. There was no complication.