[Anomalous systemic arterial supply to the basal segment of the left lung; report of a case].

A 35-year-old female was admitted to our hospital for hysteromyoma. Chest X-ray showed a mass shadow in the left lung field. A thorough examination revealed anomalous systemic arterial supply to the basal segment of the left lung with 2 abnormal arteries. Because the patient had no symptoms, no operation was performed. After 9 months however, the patient had bloody phlegm and chest pain and received an operation. Thus, we propose that the operation for the pulmonary sequestration is to be performed when such a diagnosis is made.