Traditionally and still often referred to as bronchoalveolar carcinoma (BAC), this form of lung cancer is now classified as adenocarcinoma in situ, minimally invasive adenocarcinoma and invasive adenocarcinoma of the lung based on histological findings.

Classically, it presents insidiously with an unresolving pneumonic process, but can also present as a pulmonary nodule or cluster of diffuse nodules as in this case.

Three recognized radiographic patterns are described:

• single mass or nodular form: ~45%
• consolidative form: ~30%
• multinodular form: ~25%