A case of poorly differentiated lung adenocarcinoma showing air-space consolidation caused by aerogenic metastasis]

A 78-year-old woman was admitted to our hospital because of dyspnea. A chest radiograph and a computed tomogram on admission showed air-space consolidation in the left upper lung field, and so pneumonia was diagnosed. Although antibiotics were administered, the air-space consolidation did not improve. A transbronchial lung biopsy was performed, yielding a pathologic diagnosis of poorly differentiated lung adenocarcinoma. Despite combination chemotherapy with docetaxel and UFT, the air-space consolidation expanded, and the patient finally died of respiratory failure 3 months after diagnosis. Autopsy revealed air-space consolidation due to poorly differentiated lung adenocarcinoma, with large atypical cells diffusely floating in the alveolar spaces. It has been recognized that bronchiolo-alveolar carcinoma and well-differentiated lung adenocarcinoma present with air-space consolidation, reflecting the cancer cells lining the alveolar walls. However, in this case, the air-space consolidation was due to cancer cells diffusely floating in the alveolar spaces in aerogenic metastasis. It was considered that this is a rare case, which presented with a very interesting development pattern.