Mucosal bridge formation in a patient with esophageal epidermoid metaplasia.

Esophageal mucosal bridge formation is an uncommon condition that is believed to result from mucosa injury. Ingestion of corrosive agents, mediastinal radiation therapy, and variceal sclerotherapy have been identified as possible causes, but mucosal bridges within the esophagus have also been described in chronic inflammatory conditions such as Crohn’s disease [1,2]. A 53-year-old man with a long history of smoking and chronic obstructive pulmonary disease presented with dysphagia andbolusobstruction. Endoscopyrevealed multiple coalescent white patches and plaque-like lesions thatcovered largeparts of the esophageal mucosa (●" Fig.1a). In themiddle portion of the esophagus, large irregular mucosal bridges were found that linked the anterior and posterior walls transversely across the lumen (●" Fig.1b), ultimately leading to double-lumen formation (●" Video1). Biopsies obtained from the white patches proved epidermoidmetaplasia of the esophagus, characterized by squamous epithelium with a well-developed granular cell layer, hyperorthokeratosis with focal parakeratosis, and mild peripapillary lymphocytic infiltrate (●" Fig.2). Esophageal epidermoid metaplasia is a rare finding, which mainly affects the middle-to-distal esophagus. Cottreau et al. [3] reported a 0.19% incidence when investigating 1048 consecutive patients. The condition is characterized by plaquelike lesions with a nodular pattern on narrow-band imaging [4]. It is believed to represent an unusual response to mucosal injury. Risk factors seem to be similar to those of its oral counterpart, and associations with tobacco smoking and chronic alcohol intake have been described [4,5]. Differential diagnoses mainly include pill-induced esophagitis, corrosive damage, and sloughing esophagitis. Although the preneoplastic potential of the condition has not been established definitively, association with squamous dysplasia and squamous cell carcinoma has been observed [5]. In conclusion, mucosal bridges in the esophagus are rare. The association with epidermoid metaplasia, which is reported here for the first time, suggests common pathogenetic pathways related to injury and repair.