[A case report of anomalous systemic arterial supply to the left basal lung].

A 38-year-old woman with a history of hemosputum once in a several years was admitted to our hospital because of a mass shadow in the left lower lung field on chest X-ray film. Physical examination revealed neither cardiac murmur nor any sign of heart failure. Chest X-ray film showed a tumorous shadow in the left posterior basal segment. Chest CT scan showed that this shadow was consisted of enhanced, dilated and torutuous vessel and was connected to the descending thoracic aorta. Angiographic examinations showed that there was no normal left basal trunk of the pulmonary artery, and revealed an anomalous arterial supply to the basal segments from the descending thoracic aorta, with an expanded left inferior pulmonary vein. Broncho-fiberscopy showed no abnormal findings in the bronchial tree except for mild stenosis of the left basal bronchus. This case was diagnosed as an anomalous systemic arterial supply to the left basal lung (Pryce type I). The left lower lobe without pulmonary sequestration and the anomalous systemic artery were resected. Microscopically, the anomalous artery showed an elastic type, and the peripheral lung areas showed congestion. The postoperative course was uneventful. We collected reports of 26 cases of the same anomalies in Japan and discussed the difference of this anomaly from pulmonary sequestration.