The necessity of histology.

The overwhelming majority of primary lung malignancies are secondary to smoke inhalation and occur in the older adult population in the presence of symptoms that are usually suspicious for an underlying malignancy. A chest radiograph is the initial imaging modality of choice to diagnose a lung cancer. However, a small percentage of lung cancer occurs despite a lack of smoking history whatsoever and in asymptomatic individuals. This case outlines an example of a rare type of primary lung cancer found to be metastatic at diagnosis in a young adult despite the patient being virtually asymptomatic and not having a smoking history. It demonstrates the absolute necessity in considering primary lung cancer as a diagnosis even in younger patients without a smoking history who are asymptomatic if there is no definite etiology for an abnormal chest radiograph.