Solitary pulmonary metastasis: an enigma

Lung metastases, which are an expression of the new phase of the underlying neoplastic disorder, have been treated in the recent years by multiple disciplinary approach. When the metastases to the lungs are multiple, it is indicative of extensive tumor burden, and the organ plays an insignificant role in the distribution of the metastases in the different lobes of the lungs. However, when the pulmonary metastases appear after a prolonged disease-free interval it becomes an enigma; when the metastases are solitary, the majority (over 80% in this series) are located in the upper zone of the lungs. This study of 28 patients with solitary lung metastases explores the possible etiology of this clinical observation and proposes that the pattern of perfusion and anatomopathological features of the upper lobes are the main reasons why these lobes are prevalently the sites for solitary lung metastases.