Pulmonary nodules in extrapulmonary cancer: a clinical problem to be answered

Introduction: The objective of this study was to describe the clinical, radiological, and causal characteristics of pulmonary nodules, analyzing the association between findings in subjects with a prior diagnosis of extrapulmonary malignancies between 2018 and 2023 at an oncological center in Colombia. Method: A single-center, retrospective observational study evaluating cases identified from a thoracic surgery database, all with histopathological evaluation of the dominant nodule. Results: One hundred ninety-seven individuals (median age: 65 years, 59.9% women). The most frequent oncological histories were lower digestive tract tumors (18.5%) and breast tumors (14.8%). Overall, 72.1% of the nodules were malignant: 55.3% metastases and 16.8% de novo primary lung tumors. In the logistic regression, metastatic etiology was associated with multiple nodules (OR: 3.88), lobulated edges (OR: 9.23), and a time interval greater than 12 months from the primary tumor (OR: 2.82). Likewise, de novo primary tumor etiology was associated with female sex (OR: 3.91), subsolid nodules (OR: 6.08), lobulated edges (OR: 6.77), and spiculated edges (OR: 5.44). Agreement between diagnostic imaging and histopathological results was low (κ = 0.18), but improved after an expert review of the studies (κ = 0.48). Conclusions: In individuals with extrapulmonary malignancies, the presence of multiple nodules, lobulated edges, and intervals exceeding 12 months suggests metastatic etiology. Conversely, female sex, subsolid nodules, and lobulated or spiculated edges point toward a de novo primary lung tumor. Specialized review of images contributes to improving diagnostic accuracy.