What is the hallmark symptom of a Pancoast tumor?

A Pancoast tumor, which is a type of lung cancer that occurs at the apex of the lung, often has distinct symptoms that set it apart from other lung tumors. The hallmark symptom of a Pancoast tumor is shoulder pain. This pain arises due to the tumor's proximity to the brachial plexus and surrounding structures, which can lead to irritation or invasion of nerve pathways. In many cases, patients describe the pain radiating from the shoulder down the arm, and it may be accompanied by other neurological symptoms such as weakness or atrophy of the hand muscles.

The presence of shoulder pain is not merely a consequence of the tumor but often serves as one of the earlier manifestations that prompts individuals to seek medical attention. This symptom can sometimes be mistaken for musculoskeletal issues, which can delay accurate diagnosis.

Other symptoms associated with Pancoast tumors, like cough or hemoptysis, may occur but are not unique to these tumors and are more commonly seen in other types of lung cancer. Chest pain can also occur but, similar to cough and hemoptysis, is not as characteristic of Pancoast tumors specifically. Thus, shoulder pain stands out as the most defining symptom in the clinical presentation of a Pancoast tumor.