Axial CT images show a large mass (stars) in the left lower lobe with a large left pleural effusion with focal pleural thickening (arrowheads). The lung mass is better seen on a post-thoracentesis image. Transbronchial biopsy revealed adenocarcioma and pleural fluid cytology confirmed the presence of malignant cells. Based on the new staging system, this patient has at least M1a disease.
- Additional "satellite nodule in the same lobe" now classified as T3 (previously T4)
- Additional "satellite nodule in the different ipsilateral lobe" now classified as T4 (previously M1)
- No change in N staging, but a new node map has been developed to address the issue of boundaries between different nodal stations
- M staging is now subdivided into M1a and M1b to address significantly different prognosis: "contralateral pulmonary nodule (malignant)" and "pleural dissemination" now classified as M1a; distant metastasis as M1b