Pulmonary Azygos Lobe on Chest X-ray and CT: Recognizing a Normal Variant Without Missing a Pulmonary Metastasis
When an Abnormal Line in the Right Upper Lung Is Not a Tumor Edited by ScholarGen MediAI Executive Clinical Summary A thin, unusual line in the right upper lung field on a chest radiograph can immediately raise concern for a pulmonary lesion, pleural abnormality, or mediastinal pathology. Yet one of the most important possibilities is not disease at all: pulmonary azygos lobe , a rare congenital anatomical variant produced by an unusual course of the azygos vein and associated pleural reflection. The diagnostic challenge becomes considerably more important in an oncology patient. In the present case, a teenage boy receiving chemotherapy for left femoral osteosarcoma underwent routine chest radiography. An abnormal linear structure was identified in the right upper lung field. Subsequent chest CT demonstrated an azygos fissure containing an enhancing azygos vein. However, CT also demonstrated a separate approximately 1-cm pulmonary nodule in the posterior right upper lobe. The nod...
