Scan and biopsy. A scan of the chest should show it and a biopsy should confirm it.
Cough, shortness of. Breath. Many are don't cause symptoms and the type of adenoma can determine what symptoms, if any a person has.
Bleeding. Hemoptysis, a bloody sputum, would be the hallmark of this condition.
Primary brain tumor. This is a serious aggressive cancer in a critical location of the brain. Location in the brain stem usually makes it inoperable. Consult with your cancer doctor.