Pulmonary lymphangiectasis presenting as solitary pulmonary coin lesion

Pulmonary lymphangiectasis is a rare anomaly of infancy characterized by dilatation of pulmonary lymphatic vessels. It is considered to occur exclusively in young children and neonates, and pulmonary lymphangiectasis in asymptomatic adults is rare. Moreover, because chest radiography usually demonstrated the generalized congestive pattern of increased pulmonary vascularity or a reticulonodular pattern, it is extremely unusual for pulmonary lymphangiectasis to be demonstrated as a solitary nodular lesion. There were only two case reports of lymphangiectasis that developed as a nodular shadow in asymptomatic adults in English and Japanese literature. Here, we describe two cases of pulmonary lymphangiectasis that were demonstrated as solitary coin lesions in asymptomatic adults without any extrapulmonary manifestations. An 84-year-old male and a 48-year-old male were found to have a gradually increasing round pulmonary nodule. Chest computed tomography (CT) demonstrated a smooth round nodule on the lung surface, and video-assisted thoracoscopic wedge resection was performed. The nodule was a thin-walled cyst containing yellowish liquid. Histological examination of the resected lung demonstrated lymphangiectasis in the subpleural and interlobular connective tissue and no abnormal cell proliferation. Therefore, we considered that the pulmonary nodule had been formed as a result of local fluid collection in pulmonary lymphangiectasis.