Final answer:
A Pancoast tumor is found in the superior portion of the lung, often involving the apex of the lung, and extending into the chest wall. It can cause pulmonary symptoms such as cough, dyspnea, and chest pain, and may be associated with Horner's syndrome.
Step-by-step explanation:
A Pancoast tumor is found on a chest X-ray (CXR) in the superior portion of the lung, often involving the apex of the lung. Specifically, it arises from the upper part of the right or left lung and extends into the chest wall. The tumor can cause pulmonary symptoms such as cough, dyspnea, and chest pain, and may also be associated with Horner's syndrome due to involvement of the sympathetic nerves.