Basic and Clinical Sciences (BCSE) Practice Exam

In which form of lung cancer is Pancoast syndrome most commonly observed?

1. Small cell lung cancer (SCLC)

2. Non-small cell lung cancer (NSCLC)

3. Large cell lung cancer

4. Squamous cell carcinoma

The correct answer is: Non-small cell lung cancer (NSCLC)

Pancoast syndrome is most commonly observed in squamous cell carcinoma, which is a subtype of non-small cell lung cancer (NSCLC). This syndrome results from a tumor located at the apex of the lung, which can invade surrounding structures such as the brachial plexus and sympathetic chain, leading to a characteristic set of symptoms including shoulder pain, Horner's syndrome, and atrophy of the hand muscles. While squamous cell carcinoma is a type of non-small cell lung cancer, it’s important to note that Pancoast tumors are specifically linked to the location of the tumor and its capacity to invade neighboring tissues. The other types of lung cancer mentioned can occur throughout the lung but are less commonly associated with Pancoast syndrome in the context of causing these specific symptoms due to their usual locations and growth patterns. Therefore, recognizing the strong association between Pancoast syndrome and squamous cell carcinoma within the broader category of non-small cell lung cancer is critical in understanding this clinical scenario.