[Fistula of the pyriform sinus. Report of 2 cases].

The authors present two patients of 8 and 11 years of age that presented a left sided piriform sinus fistula diagnosed by esophagram and surgically treated in our centre. One had been operated previously with a diagnosis of relapsing thyroglossal quist on five occasions. The piriform sinus fistula is a recently recognised entity as cause of thyroiditis and suppurative cervical infections in the pediatric age. Communicated for the first time in the literature in 1957 by Japanese authors, it was not until 1973 that Tucker published for the first time in English a case of recurrent cervical abscess caused by a fistula initiated in the piriform sinus. Until now very few cases have been published. The majority of authors consider it to be an embryological residue of the third or fourth pharyngeal pouch. The key to diagnosis is to bear it in mind whenever a patient presents suppurative thyroiditis or repetitive cervical infections, principally of the left side. An esophagram is necessary to demonstrate the course of the fistula. In cases of thyroiditis a thyroidal gammagraphy will allow vision of a cold zone in the upper third of the affected lobe. Treatment consists of total extirpation of the fistula and affected portion of the thyroidal lobe, once the infection has been solutioned. Before intervention it is important to collocate a tube in the fistula's course by means of a direct microlaryngoscopy which will serve as guide and allow the injection of methylene blue.