Retropharyngeal abscess revealing occult upper aerodigestive tract malignancy: Report of two cases

Background: Retropharyngeal abscess (RPA) is a deep neck space infection predominantly encountered in children. In adults, it is usually secondary to pharyngeal trauma, foreign body ingestion, odontogenic infection, or immunocompromised conditions. Exceptionally, it may reveal an underlying malignant tumor of the upper aerodigestive tract.
Cases Presentation: We report two unusual cases of retropharyngeal abscess associated with occult malignancy. The first case involved a 45-year-old woman presenting with progressive upper dysphagia for six months following fishbone ingestion, complicated by dysphonia. Clinical examination revealed an inflammatory left laterocervical swelling with hypersalivation. Nasofibroscopy demonstrated posterior orohypopharyngeal bulging associated with left vocal cord paralysis. Cervical computed tomography (CT) confirmed a retropharyngeal abscess. Despite surgical drainage and broad-spectrum intravenous antibiotics, follow-up imaging revealed a superinfected cervical esophageal mass, and histopathological examination confirmed well-differentiated squamous cell carcinoma. 
The second case concerned a 27-year-old chronic smoker and alcohol consumer presenting with bilateral cervical swelling, progressive dysphagia evolving to aphagia, dysphonia, and deterioration of general condition. Endoscopic examination showed a hypopharyngeal tumor with anterior laryngeal displacement and left vocal cord paralysis. Cervical CT demonstrated hypopharyngeal wall thickening extending to the upper esophagus with bilateral cervical lymphadenopathy and associated retropharyngeal abscess formation.
Conclusion: Retropharyngeal abscess in adults, particularly when associated with chronic symptoms or atypical clinical evolution, should prompt systematic investigation for an underlying malignancy. Early recognition is essential to avoid delayed diagnosis and therapeutic management.