Final answer:
A Pancoast tumor is usually diagnosed with a computed tomography (CT) scan with contrast dye, which provides detailed images of the lung's anatomy and can reveal the presence of such a tumor and associated complications.
Step-by-step explanation:
The diagnosis of a Pancoast tumor typically involves the use of computed tomography (CT) scan with contrast dye. This imaging test is crucial for assessing the presence and extent of the tumor, commonly located at the top of the lung and often invading nearby structures. By using a CT scan with contrast dye, healthcare professionals can obtain detailed images of the lung's anatomy, which helps in identifying the Pancoast tumor and any potential complications associated with it, such as fluid accumulation or abscess formation.
Although a CT scan is pivotal for the initial detection, further evaluation often includes a biopsy and additional imaging such as magnetic resonance imaging (MRI), particularly in complex cases where the tumor's position makes a biopsy challenging or in situations where more detail on soft tissue involvement is required.