Congenital Esophageal Duplication Cyst: A Rare Cause of Dysphagia in an Adult.

Esophageal duplication cyst is a rare congenital embryonal gastrointestinal (GI) malformation which is diagnosed most commonly in childhood. In adults, they can present with a variety of symptoms ranging from dysphagia, chest pain, epigastric discomfort, and vomiting to more serious complications including infections, hemorrhage, and ulcerations. A 30-year-old male presented with gradually progressive dysphagia to solids for 4 months without significant weight loss. Clinical examination and routine laboratory examination were unrevealing. Upper GI endoscopy revealed a well-defined submucosal lesion bulging into the esophageal lumen involving the right antero-lateral wall of the distal esophagus. The overlying mucosa was normal with mild luminal narrowing but gastroscope could be negotiated across this narrowing. Differential diagnosis included lipoma, leiomyoma or GI stromal tumors. Contrast-enhanced computed tomography of thorax revealed a 3.5 × 2.3 × 3 cm well-defined homogenous hypodense lesion involving the right antero-lateral wall of the distal thoracic esophagus with likely possibility of submucosal or intramural lesion. Subsequently, endoscopic ultrasonography (EUS) revealed a 3.3 × 2.8 cm homogenous hypoechoic lesion without any vascularity involving the distal esophagus wall suggestive of duplication cyst. The lesion was intramural in location as muscularis propria was seen to go around the lesion. Bronchogenic cyst was excluded due to absence of cartilage and close proximity of the cyst to lumen. Fine-needle aspiration was not attempted in view of high risk of introducing infection. Being symptomatic, the patient underwent complete surgical excision of the cyst with exteriorization of the base which on histopathology confirmed duplication cyst. Esophageal duplication cysts are exceedingly rare congenital embryonal malformations with estimated prevalence of 0.0122% arising from aberration of posterior division of embryonic foregut at 3 - 4 weeks of gestation. This case shows that duplication cysts can rarely masquerade as submucosal tumor in adults and EUS is highly accurate in pre-operative diagnosis and therapeutic decision making. Literature search revealed only a handful of cases of EUS-guided diagnosis of esophageal duplication cyst reported in the literature.