Piriform sinus fistula. A route of infection in acute suppurative thyroiditis
A. Miyauchi, F. Matsuzuka, S. Takai, K. Kuma and G. Kosaki
Fifteen patients had acute suppurative thyroiditis resulting from infection
through the left piriform sinus fistula. Characteristic clinical features
included (1) onset in infancy or childhood, (2) left lobe involvement, and
(3) frequent recurrence unless the fistula was extirpated completely.
Fistulectomy in eight patients demonstrated three distinct courses of the
fistula: lateral to, medial to, and penetrating the left thyroid lobe.
Anatomical and histological findings suggest that the fistula is a remnant
of the third pharyngeal pouch. We believe that the fistula is a common
route of infection in acute suppurative thyroiditis, allowing bacterial
infection to begin either in the perithyroidal space, spreading into the
thyroid gland secondarily, or in the thyroid gland, primarily in cases
where it penetrates the gland. Complete removal of the fistula is essential
to a permanent cure.
