Thoracoabdominal esophageal duplication cyst in a 3-year-old girl: a case report

Abstract

Background: Esophageal duplication cysts are rare congenital foregut malformations. Large thoracic cysts may simulate transhiatal or abdominal extension on imaging, complicating operative planning. Case report: A 3-year-old girl weighing 11.7 kg (approximately 9th percentile for age, WHO weight-for-age) presented with recurrent pneumonia (four episodes over 12 months) and progressive abdominal distension. Chest radiography demonstrated a right mediastinal opacity. Contrast-enhanced computed tomography showed a giant right posterior mediastinal cystic lesion (15 × 20 × 8 cm) closely related to the esophagus with apparent extension below the diaphragm. Through a right muscle-sparing lateral thoracotomy, the cyst was decompressed and excised. A short shared wall with the mid-thoracic esophagus was managed by cyst mucosal excision while preserving the shared muscular layer, followed by primary closure. Intraoperative exploratory laparotomy performed during the same anesthesia showed no abdominal duplication cyst, confirming an isolated thoracic esophageal duplication cyst despite the preoperative radiologic appearance. Histology demonstrated respiratory-type epithelium with submucosal glands and a well-developed smooth muscle coat, consistent with a foregut duplication cyst. The postoperative course was uneventful, and the child remained symptom-free with no recurrence at 24 months. Conclusion: Large thoracic esophageal duplication cysts may appear to have an abdominal extension on imaging. Intraoperative decompression can help clarify their anatomy.