**8.2. Ultrasound diagnosis**

The prenatal diagnosis of esophageal duplication cysts is based on the spherical aspect of the cyst, rarely on the tubular aspect, but with a thick, hyperechogenic wall determined by the presence of the gastric mucosa. Usually, the cyst is connected to the esophagus. If the dimensions of the esophageal duplication cyst are large due to the compression effect on the esophagus, the appearance of polyhidramnios may occur [37, 38]. The thymic cyst is formed from remnants of the thymopharangeal duct; they are usually very small and localized to the anterior mediastinum [38]. The ultrasound aspect is of a transonic mass surrounded by the thymic tissue and located in the previous mediastinum.

**Author details**

Cringu Ionescu

**References**

**16**:178-186

2002;**41**:144-149

2000;**16**:620-624

Address all correspondence to: antoniuginec@yahoo.com

atory Journal. 2010;**35**:479-495

in Pediatric Surgery. 2003;**12**:17-37

North America. 1993;**31**:631-649

Medical Genetics. Part A. 2006;**140 A**:151-155

Department of Obstetrics and Gynecology, Clinical Emergency Hospital St Pantelimon,

Thoracic Anomalies

183

http://dx.doi.org/10.5772/intechopen.71959

[1] Guidelines of the European Respiratory Society and the European Society of Thoracic Surgeons for the management of malignant pleural mesothelioma. The European Respir-

[2] Stoecker JT, Madewell JER, Drake RM. Congenital cystic adenomatoid malformation of the lung – Classification and morphologic spectrum. Human Pathology. 1977;**8**:155-171

[3] Leninger BJ, Haight C. Congenital cystic adenomatoid malformation of the left lobe lower with compression of remaining lung. Clinical Pediatrics. 1973;**12**:182-186

[4] Langston C. New concepts in the pathology of congenital lung malformations. Seminars

[5] Laberge JM, Flageole H, Pugash D, et al. Outcome of the prenatally diagnosed congenital cystic malformation: A Canadian experience. Fetal Diagnosis and Therapy. 2001;

[6] Hernanz Schulman M. Cystic and cystic like lesions of the lung. Radiologic Clinics of

[7] Stoecker JT. Congenital airway obstruction malformation: A new name and expanded classification of congenital cystic adenomatoid malformation of the lung. Histopathology.

[8] Adzick NS, Harroson MR, Click PL, et al. Fetal cystic adenomatoid malformation prenatal diagnosis and natural history. Journal of Pediatric Surgery. 1985;**20**:483-488

[9] Wilson RD, Hedrick HL, Liechty KW. Cystic adenomatoid malformation of the lung – Review of genetics, prenatal diagnosis and in utero treatment. American Journal of

[10] Mahle WT, Ryschick J, Tian Z, et al. Echocardiographic evaluation of the fetus with congenital cystic adenomatoid malformations. Ultrasound in Obstetrics & Gynecology.

[11] Cass DL, Crombleholme TM, Howello LJ. Cystic lung lesions with systemic arterial blood supply: A hybrid of congenital cystic adenomatoid malformation and broncho-

pulmonary sequestration. Journal of Pediatric Surgery. 1997;**32**:986-990

Carol Davila University of Medicine and Pharmacy, Bucharest, Romania

Pericardial cyst, originating from the pericardium, appears at ultrasound examination as a thin walled, unilocular, fluid-filled transonic mass in the left or the right of the cardiophrenic angle. The cyst wall may communicate with the pericardial space.

Neurenteric cysts are very rare; only eight cases have been diagnosed in the prenatal stage by the ultrasound [37–39]. If the size of the cyst is large, it can exert cardiac compression with the subsequent appearance of the hydrops. It can also exert compressive phenomena on the bronchi, which causes neonatal respiratory distress. Association with anomalies of the membrane can be encountered [40].

The differential diagnosis among the described mediastinal masses is sometimes difficult. Several elements should be considered: pericardial cyst is located in the cardiophrenic angle of the right hemothorax, thymic cysts are located in the anterior mediastinum and are surrounded by thymic tissue, and the enteric duplication cyst is in close contact with the esophagus [41, 42]. For differential diagnosis, we can also use fetal MRI. The origin of the mass can be established sometimes only after perinatal autopsy [43].
