Is shoulder / arm pain from a pancoast tumor always severe?

No: It depends on the size and aggressiveness of the tumor, and how badly the nerves are irritated. Rapid severe pressure or inflammation can cause more arm symptoms. On the other hand, slower growth and gradual nerve pressure may cause little to no problem.

Pancoast was a: Radiologist that noted tumor at the top of the lung burst upward, involve sympathetic nerve plexus, and the nerve roots before, as and after they enter the brachial plexus. The tumors tend to be insidious, so the arm pain may be gradual. These tumors can be difficult to diagnose because the shoulder arm pain make people think orthopedic rather than oncologic. Pancoast was wrong. These can be cured.