Isolated lung is a rare congenital malformation of lung development in which a cystic mass is formed by a portion of the lung tissue supplied by an abnormal arterial supply of the body circulation. This portion of the lung tissue may communicate with the bronchi, causing recurrent episodes of limited infection, or when it does not communicate, no respiratory symptoms are present, also known as bronchopulmonary isolation. The clinical feature is the presence of an abnormal arterial blood supply. The main treatment for this disease is surgical removal of the diseased lung tissue. Isolated lung is a congenital disease (non-genetic disease) in which the blood vessels connecting the primitive aorta to the primitive lung do not degenerate during lung development, and the high-pressure blood flow compresses part of the lung and affects its development, causing cystic and fibrotic changes to occur, resulting in isolation. Jiyun Tang, Department of Obstetrics, Affiliated Hospital of Jining Medical College The disease can be divided into intralobar type and extralobar type. The intralobar type is wrapped under the same pleura with normal lung tissue and has a close anatomical relationship with the bronchus and is symptomatic; the extralobar type is wrapped under its own abnormal pleura and is relatively independent of the normal lung and is asymptomatic, but 50% can be combined with other malformations, such as diaphragmatic hernia, cardiovascular malformation, pulmonary hypoplasia, spinal malformation and esophageal malformation. The intralobar type is clinically common. The clinical symptoms of isolated lung are divided into three categories: 1, respiratory symptoms mainly occur in the intrafollicular type, with clinical manifestations of recurrent lung infections, cough, sputum, and even hemoptysis. 2, asymptomatic mainly in the extralobar type of isolated disease, only in the chest X-ray manifested as intrapulmonary mass shadow. 3, cardiovascular symptoms this performance is extremely rare, mainly for isolated disease blood supply vessels to blood shunting resulting in heart failure. Auxiliary examinations: 1. Elevated white blood cell count in the case of co-infection. 2. Chest X-ray: it shows a density-enhanced and uneven shadow with clear borders, lobulated, or may be accompanied by single or multiple cystic dilated shadows, located in the posterior basal segment of the lower lobe and connected to the diaphragm. In the case of combined pneumonia, the lung inflammatory infiltrative shadow appears along with the isolated lung tissue and adjacent normal lung tissue, and after the inflammation is controlled, the adjacent lung tissue returns to normal, while the isolated lung tissue shadow still persists. 3, chest enhanced CT scan and magnetic resonance imaging (MRI): can clearly show the abnormal blood supply artery into the isolated disease area, which is beneficial to confirm the diagnosis. Arteriography can confirm the diagnosis of the disease and is only used in some special cases. 4, ultrasonography: prenatal ultrasound scan at 22-33 weeks of gestation may make the diagnosis. Complications: Intralobar lung isolation is often complicated by pneumonia. The extralobar type is often combined with other malformations, such as diaphragmatic hernia, ventricular septal defect, ectopic drainage of pulmonary veins, pericardial cyst, funnel chest, spinal malformation, and pulmonary dysplasia. Treatment: The main treatment for pulmonary segregation is surgical removal of the diseased lung tissue. Most of those detected by prenatal ultrasound scan can be treated according to the condition after delivery, and those with excessive amniotic fluid need prenatal treatment.