A rare cause of dysphagia due to retropharyngeal foregut duplication cyst: case report and review of the literature

Background: The retropharyngeal space is a deep compartment of the head and neck region which extends from the base of the skull to the mediastinum, between the posterior pharyngeal wall and vertebral muscles, delimited laterally by carotid sheaths. Pathological processes of the retropharyngeal space are rarely encountered, generally are isolated and painless masses often cystic, and they usually originate from branchial arch anomalies, but only in rare cases, they turn out to be foregut duplication cysts. Foregut duplication cyst is rare congenital malformations arising along primitively derived alimentary tract during the first trimester in the developing embryo, mostly seen in the thorax and abdomen, with just few cases reported in the head and neck region. We report an extremely rare case of a foregut duplication cyst lined with respiratory epithelium located in the retropharyngeal space, at the level of the oropharynx, of an adult patient with dysphagia surgically treated, and we also made an analysis of the published literature about this very uncommon condition. Case presentation: A 63-year-old male patient with chronic dysphagia was diagnosed with a retropharyngeal cystic lesion, which was surgically treated. Final pathologic evaluation confirmed the diagnosis of a rare foregut duplication cyst lined with respiratory epithelium. A review of the pertaining published literature about the head and neck foregut duplication cysts was made, with a particular emphasis on retropharyngeal ones. Conclusions: Retropharyngeal foregut duplication cysts are a very rare congenital cyst of the head and neck. Clinical symptoms such as dysphagia and dyspnea should be evaluated with fibrolaryngoscopy, and CT and MRI scans are of great significance for definitive diagnosis, which should include the possibility of a foregut duplication cyst in the differential diagnosis. Surgical excision is the elective treatment for this lesion, in order to prevent complications including infection and compression symptoms or eventually malignant transformation.