Which type of non-small cell lung cancer is categorized as a peripheral mass?

Adenocarcinoma is typically categorized as a peripheral mass in non-small cell lung cancer. This type arises from the mucous glands of the lungs, often located in the outer regions of the lungs, hence its association with peripheral masses. This localization is an important distinguishing feature, as many patients with adenocarcinoma might present with masses observed on imaging studies, specifically in the pleural or subpleural areas.

In contrast, squamous cell carcinoma tends to originate in the central airways and is more often associated with endobronchial lesions. Large cell carcinoma is also generally found centrally and may manifest as a large mass but isn't specifically peripheral. Small cell carcinoma, on the other hand, is more closely associated with central lung structures and often presents in a way that doesn't align with the definition of a peripheral mass.

Understanding the typical localization of these cancers can aid in both diagnosis and management, particularly in distinguishing between different subtypes of lung cancer based on imaging and clinical presentation.