Aggressive Cystic and Cavitary Appearances in Lung Adenocarcinoma

A 65-year-old woman visited our department due to the presence of a dry cough. On auscultation, crackles were heard predominantly in both lung bases. Chest radiography showed bilateral nodular opacities (Picture 1). Chest computed tomography showed nodules, cysts, pseudocavitations (arrowheads), and masses with cavities (Picture 2). Although septic emboli, tuberculosis, fungal infection, and cystic pulmonary metastasis were considered, transbronchial lung biopsy showed tumor cells proliferating in a glandular fashion with foci of fibroblastic proliferation and a lepidic pattern, which was consistent with lepidic adenocarcinoma (Picture 3). Pulmonary metastasis was excluded based on the findings from positron emission tomography scanning and other imaging procedures. Generally, cysts and/or cavitation in lung cancer are caused by several mechanisms, such as a check-valve obstruction, necrosis, or disruption of the alveolar wall by a tumor (1). Although cysts and cavitation are rarely observed in lung adenocarcinoma, their aggressive