This is for my mom aged 55. She has been experiencing sharp ache down her left arm for 4 months (which is worse at night.) The pain starts from the bottom of the skull, radiates to the upper back, shoulders and finally travels to the left arm and fingers. Pain killers and exercises are not helping. She also gets mild morning cough (with little or no phlegm) and random episodes of breathlessness (specially after morning physical activity). She has always been a healthy person. She has never smoked. From what I have read on the internet, these are the symptoms of a pancoast tumor or lung cancer that has metastasized to the bones.
Note- She got a chest X ray 4 years back which came back clear, no diabetes, no hypertension, blood work normal, abdominal usg (3 months back) also normal.