Extrapleural and cardiophrenic lymph nodes: prevalence, clinical significance and diagnostic value

Purpose: The aim of this study was to evaluate the prevalence, clinical meaning and diagnostic value of extrapleural and cardiophrenic nodes occasionally observed on computed tomography (CT) scans of the chest. Materials and methods: We included 750 consecutive patients who underwent CT of the chest for different clinical purposes (340 nonneoplastic patients, 270 with extrathoracic neoplasms, 120 with intrathoracic neoplasms, 20 with pleural metastasis) and 91 patients with histologically proven malignant pleural mesothelioma (MPM). For each group of patients, we analysed the presence of extrapleural and cardiophrenic nodes, their number (single or multiple) and their size. Results: The prevalence of cardiophrenic nodes between 6 and 10 mm and >10 mm was significantly higher in patients with MPM (28.6 and 26.4 %, respectively) than in all other categories of patients, except for patients with pleural metastasis (30 and 25 %, respectively). The prevalence of extrapleural nodes, independently from their size, was significantly higher in patients with MPM (68 %) compared with all other groups, including patients with pleural metastasis (5 %; p<0.0001). Conclusions: Cardiophrenic nodes >5 mm and extrapleural nodes of any size have a significant diagnostic value in malignant pleural disease, either primary or secondary, whereas they are extremely rare in other neoplastic or nonneoplastic diseases.