A case report of contrast-enhanced harmonic ultrasonography for the diagnosis of an esophageal duplication cyst

A 54-year-old man was referred to our hospital because of a suspected esophageal submucosal tumor on upper gastrointestinal radiography. Contrast-enhanced computed tomography showed a 52 mm homogeneous mass attached to the lower thoracic esophagus. Esophagogastroduodenoscopy revealed a 50 mm submucosal tumor in the lower esophagus, and endoscopic ultrasonography (EUS) showed a continuous hypoechoic lesion in the esophageal muscularis propria. Contrast-enhanced harmonic EUS revealed a non-echogenic area. T1 and T2 magnetic resonance imaging revealed a high-signal lesion. Based on imaging studies, an esophageal duplication cyst was diagnosed. Although asymptomatic, the patient underwent video-assisted thoracic surgery because of the possibility of rupture and the appearance of symptoms due to a future infection or enlargement, although this was not noted before. In our case, the esophageal duplication cyst appeared as a hypoechoic mass, requiring differentiation from submucosal tumor other than the cyst. Histologically, the cyst was covered by two layers of muscle covered by the chorioepithelial columnar epithelium. EUS fine-needle aspiration is effective in diagnosing submucosal tumor but also carries the risk of infection. Contrast-enhanced ultrasonography was used in this case to observe the interior and reach a preoperative diagnosis. Contrast-enhanced harmonic EUS appears to be effective in examining the interior of submucosal tumor lesions noninvasively.