RESUMO
Pyriform sinus fistula is a rare malformation causing recurrent cervical abscesses and acute suppurative thyroiditis, with a low incidence in general, as the thyroid gland is remarkably resistant to infections. The aim of this paper is to describe the clinical data, diagnosis, treatment and evolution of four cases of pyriform sinus fistulas treated at our institution over the last 15-year period. All appeared at the beginning with left laterocervical inflammatory tumours, with radiological signs of acute suppurative thyroiditis in one case and with heterogeneous masses near the isthmus of the thyroid gland in the rest of them. The fistulous tracts were delineated by barium studies and/or fibro-laryngoscopy. The treatment of the acute phase consisted of broad-spectrum antibiotic therapy with an initial incision and drainage procedures. At the end, a subsequent fistulectomy was made. A left hemithyroidectomy was accomplished at two cases. All the patients remained asymptomatic after the treatment except one girl that suffered recurrence seven years later. For a suitable diagnosis a high index of suspicion are necessary. The best therapeutic option is a good delineation and complete excision of the fistulous tract by cervical approach until disconnecting it of its origin at the hypopharynx. In order to avoid recurrences, the resection of the portion of the involved thyroid gland is recommended.
