What type of lung neoplasm is most likely in a smoker presenting with hemoptysis and a lung mass?

In a smoker presenting with hemoptysis and a lung mass, squamous cell carcinoma is the most likely type of lung neoplasm. This is primarily due to the strong association between squamous cell carcinoma and cigarette smoking, as well as its typical presentation in symptomatic patients.

Squamous cell carcinoma often arises from the central airways and is commonly linked to smoking, making it a frequent diagnosis among this patient population. One of the hallmark features of squamous cell carcinoma is the tendency to cause respiratory symptoms such as hemoptysis, which arises from involvement of the bronchial epithelium and potential ulceration of the tumor.

Additionally, the presence of a lung mass that is indicative of malignancy makes squamous cell carcinoma a stronger candidate, particularly in lighter smokers or those who have not smoked for an extended time, as it can still develop. This type of cancer may also lead to paraneoplastic syndromes linked to the release of different hormones like parathyroid hormone-related peptide (PTHrP), contributing to further complications in these patients.

While other lung neoplasms have their own associations with smoking, such as small cell carcinoma and adenocarcinoma, the specific combination of smoking history, hemoptysis, and the