Impact of resection type on outcomes in N0 NSCLC with "pulmonary metastasis in a different ipsilateral lobe (PM-DIL)": Is lung preservation beneficial

<bold>Objectives:</bold> Pulmonary metastasis in a different ipsilateral lobe (PM-DIL) is an uncommon form of non-small cell lung cancer (NSCLC), categorized as T4 in the 8th TNM classification. Although pneumonectomy ensures complete oncologic resection, it is linked to significant morbidity and long-term pulmonary function loss. This study compares pneumonectomy with lobectomy plus wedge resection (L+W) in strictly N0 PM-DIL patients. <bold>Methods:</bold> From 2008 to 2021, a total of 2,172 NSCLC patients underwent anatomical lung resections at our institution; 34 patients met the inclusion criteria. Of these, 12 underwent pneumonectomy, while 22 had L+W. Demographics, tumor features, and clinical outcomes were analyzed. Overall survival (OS) and disease-free survival (DFS) were evaluated using Kaplan–Meier analysis. <bold>Results:</bold> Overall postoperative mortality was 3%, with a higher rate in the pneumonectomy group (8.3% vs. 0%), though this difference was not statistically significant (p=0.169). Recurrence rates were similar (33.3% vs. 36.4%, p=0.860). The median OS was 40 months for pneumonectomy and 65.2 months for L+W (p=0.774). Multivariate analysis identified older age and large cell carcinoma as poor prognostic factors, while L+W exhibited a protective trend. <bold>Conclusions:</bold> For N0 PM-DIL patients, lobectomy plus wedge resection appears to offer comparable oncologic outcomes to pneumonectomy while reducing morbidity. Prospective, large-scale studies incorporating molecular profiling are essential to refine surgical strategies for this unique NSCLC subgroup.