[Retropharyngeal abscess due to a congenital pyriform sinus fistula in a teenager].

Pyriform sinus fistulas are rare anomalies of the branchial arches. The most common form of presentation in children and adolescents is acute suppurative thyroiditis and/or recurrent lateral cervical abscesses. However, fistulas can manifest atypically. The rarity of this pathology and the atypical clinical presentation can delay the diagnosis increasing the risk of recurrent infections and complications. We present the unusual case of a 13-year-old teenager with retropharyngeal abscess due to a congenital pyriform sinus fistula successfully treated by endoscopic electrocautery.