Per UWORLD- Adenocarcinoma is associated w/ lung scarring related to granulomatous disease, old COPD (chronic) and damage due to recurrent pneumonia.

It was the only peripheral lung cancer, its also more common in women. Metastasis would have shown multiple lesions

According to Dr Sattar.. Adenocarcinoma is the most common cause of lung cancer in female non smokers.

According to the Nurses' Health Study, the risk of pulmonary adenocarcinoma increases substantially after a long duration of tobacco smoking: smokers with a previous smoking duration of 30–40 years are more than twice as likely to develop lung adenocarcinoma compared to never-smokers (relative risk of approximately 2.4); a duration of more than 40 years increases relative risk to 5.[8]

This cancer usually is seen peripherally in the lungs, as opposed to small cell lung cancer and squamous cell lung cancer, which both tend to be more centrally located,[9][10] although it may also occur as central lesions.[10] For unknown reasons, it often arises in relation to peripheral lung scars. The current theory is that the scar probably occurred secondary to the tumor, rather than causing the tumor.[10] The adenocarcinoma has an increased incidence in smokers, and is the most common type of lung cancer seen in non-smokers and women.[10] The peripheral location of adenocarcinoma in the lungs may be due to the use of filters in cigarettes which prevent the larger particles from entering the lung.[clarification needed][11][12] Deeper inhalation of cigarette smoke results in peripheral lesions that are often the case in adenocarcinomas of the lung. Generally, adenocarcinoma grows more slowly and forms smaller masses than the other subtypes.[10] However, it tends to metastasize at an early stage.[10]