My chest x-ray "there are very small bilateral either c7 cervical rib or mildly prominent transverse processes at c7." what does this mean?

There are: Congenital ribs that you are born with that form at the C7 vertebrae. There are normally no ribs there. Sometimes there are these small ribs. The significance is hard to say. Most of the time they are something you see on an X-ray. Sometimes they pinch nerves, muscles and other structures in the neck.

Usually coincidental: But if you have compression over the brachial plexus in the shoulder, causing neurogenic or vascular thoracic outlet syndrome, leading to arm pain, numbness, weakness, then a question of mechanical effect is relevant. Sometimes, surgical excision is the best solution for such an impact.