[An elderly case of anomalous systemic arterial supply to the normal basal segment of the left lower lobe and summary of reports of the disease in Japan].

A 69-year-old asymptomatic woman was admitted because of an abnormal chest shadow. Chest X-ray films showed a tumorous shadow behind the heart. Chest CT scans showed an aberrant artery branching from the thoracic aorta and supplying the left basal segment, but the bronchial tree was normal. The left lung vein was normal but wide, and the left lower pulmonary artery could not be observed. Based on these findings, we diagnosed anomalous systemic arterial supply to the normal basal segment of the left lower lobe. Because this patient had a high risk of heart failure and pulmonary hypertension, we decided to perform a left lower lobectomy, but she refused the operation. As this disease is generally found in younger patients, diagnosis in older age, as in the present case, is rare. In this report we also summarize 39 other reports of this disease in Japan.