A 37-year-old (G4P3) woman was referred to our hospital at 32 weeks of gestation for the evaluation of a fetus with an intrathoracic cystic lesion. Ultrasonography and magnetic resonance imaging revealed that a fetal cystic lesion without a mucosal layer was located in the posterior mediastinum. These findings were consistent with a bronchogenic cyst. At 38 3/7 weeks of gestation, an elective cesarean section was performed because of her previous cesarean section. A female neonate without any external anomalies, weighing 2,442 g, with Apgar scores of 8 and 9, and requiring no resuscitation was born. Four weeks after delivery, the neonate was admitted because of respiratory distress due to mass effect. At right lateral thoracotomy, a 105 × 65 mm of solitary smooth-walled cyst containing serosanguineous fluid was found in the posterior mediastinum, which was excised completely. Histologic examination revealed the diagnosis of the mediastinal gastric duplication cyst. The neonate made an uneventful recovery. Accurate diagnosis is not necessary, but detection and continuous observation are logical. Although gastric duplication, particularly intrathoracic, is a rare pathology, it should be considered in the differential diagnosis of any intrathoracic cyst.
Foregut duplication cysts are rare congenital anomalies of enteric origin; they constitute 10%–18% of all mediastinal lesions. They are further subdivided into bronchogenic, esophageal, gastric, enteric, and pancreatic cysts [
A 37-year-old (G4P3) woman was referred to the University of the Ryukyus Hospital at 32 weeks of gestation for the evaluation of a fetus with an intrathoracic cystic lesion. An US examination revealed a 39 × 30 × 44-mm sized monocystic lesion in the mediastinum, in which the aortic arch was displaced upward (Figure
Ultrasound examination shows a 39 × 30 × 44-mm sized monocystic lesion in the mediastinum, in which the aortic arch was displaced upward.
T2-weighted magnetic resonance imaging shows fetal cystic lesion located in the posterior mediastinum without communication to surrounding organs.
Four weeks after delivery, the neonate was admitted because of respiratory distress due to mass effect. Computed tomography scans (right panel: age 2 days, left panel: age 4 weeks) show enlargement of the mediastinal cystic lesion.
A 105 × 65 mm of solitary smooth-walled cyst containing serosanguineous fluid was excised completely (right panel). Histologic examination shows an inner lining of gastric mucosa and an outer smooth muscle coat (left panel), leading to the diagnosis of the mediastinal gastric duplication cyst.
The diagnosis of intrathoracic cysts is challenging because of several possible pathologic findings, including bronchogenic cysts, neurenteric cysts, and other foregut duplication cysts. Most intrathoracic alimentary tract duplications present before the age of 2 years [
Duplication cysts can present various symptoms, such as dyspnea, stridor, or persistent cough, according to the location and type of the cysts. Asymptomatic patients later become symptomatic because of cyst enlargement, which was seen in our patient [
The etiology of enteric duplication remains speculative. The most accepted theory “split notochord syndrome” postulated the abnormal separation of the notochord from the endoderm, leading to enteric duplications [
The authors declare that there are no conflicts of interest regarding the publication of this paper.
The authors would like to thank Enago (