Piriform sinus fistula as a route of infection in acute suppurative thyroiditis.

A case of acute suppurative thyroiditis due to a left piriform sinus fistula was reported. A five-year old boy had a acutely painful tumor in the anterior part of the neck. It was a diffuse, firm, warm erythematous tumor, and laboratory, radiologic findings showed the acute inflammation of the left lobe of thyroid. a barium swallow revealed a very thin fistula originating from the apex of the left piriform sinus extending antero-inferiorly. This fistula was considered to be a route of infection in acute suppurative thyroiditis, allowing bacterial infection to begin in the perithyroidal space and spread to the thyroid gland. The complete fistulectomy was required for a permanent cure, but an administration of antibiotics was very effective in this case.