[Pyriform sinus fistulae].

Pyriform sinus fistulae (PSF) are rare branchial pouch anomalies. In most previously described cases the anomaly is located on the left side. PSF should be suspected in cervical inflammatory processes (cervical abscesses and types of suppurative thyroiditis). We report two cases of acute thyroiditis and deep cervical abscesses secondary to PSF, which were diagnosed and treated in our hospital in the last 2 years. Both presented inflammatory cervical masses associated with painful swallowing, high fever and laboratory findings compatible with acute infection. In both cases the diagnosis of PSF was confirmed by barium esophagogram. Cervical ultrasonography and computed tomography were also performed. The treatment of choice consists of broad-spectrum antibiotic therapy during acute exacerbation and subsequent fistulectomy. Definitive surgical treatment prevents recurrences.