Symptomatic Paratracheal Air Cyst Mimicking Esophageal Diverticulum: A Rare Presentation and a Diagnostic Challenge.

A 72-year-old woman presented with symptomatic acute odynophagia, right-sided neck pain, and fever. Initial imaging with computed tomography (CT) revealed the right para-esophageal collection suggestive of a complicated lateral esophageal diverticulum. A gastrografin swallow study showed an external indentation on the right lateral aspect of the upper third of the esophagus, with subsequent relative luminal narrowing, yet no evidence of wall infiltration or esophageal diverticulum was noted, reaching the diagnosis of para-tracheal air cyst with a superadded inflammatory process rather than esophageal diverticulum. The patient underwent bronchoscopy and upper endoscopy evaluations later, which were both reported as normal studies, with no detectable opening into either the airway or the esophagus. The patient was managed conservatively with intravenous antibiotics and achieved complete resolution of symptoms. This case highlights a rare symptomatic presentation of paratracheal air cyst (PTAC) mimicking an esophageal diverticulum and emphasizes the importance of multimodal imaging and endoscopic evaluation for accurate diagnosis. Awareness of this entity is essential to avoid misdiagnosis and unnecessary surgical intervention.