[Congenital piriformo-thyroid fistula as a cause of recurrent suppurative thyroiditis].

A previously healthy five year old boy presented with suppurative, febrile thyroiditis of the left lobe with pronounced general and local signs of inflammation, normal thyroid function and lack of thyroid antibodies. Intravenous antibiotic therapy improved the condition quickly. Six and nine months later however recurrent left lobe thyroiditis occurred. Endoscopic examination showed an internal fistula from the left piriform sinus to the left thyroidal lobe which was cut out. The case report confirms previous communications, that recurrent suppurative thyroiditis is nearly always caused by a piriform sinus fistula, probably a fourth pharyngeal pouch remnant which can be cured surgically.