A Case of Actinomycotic Thyroiditis in an Adult with Piriform Sinus Fistula.

Acute suppurative thyroiditis is an uncommon infectious thyroid disease affecting mainly children and young adults. The route of infection is frequently a pyriform sinus fistula. The major pathogens responsible for acute bacterial suppurative thyroiditis are the Streptococcus and Staphylococcus species. In contrast, Actinomyces species are a very rare cause of acute suppurative thyroiditis. We experienced a case of a 23-year-old man who has presented general weakness and neck pain. Thyroid ultrasonography showed an ill-defined area of heterogeneous hypoechogenicity in the left lobe of the thyroid gland. Histologic examination by fine needle aspiration demonstrated gram-positive, filamentous-like organisms with branching hyphae and characteristic sulfur granules. Barium esophagogram showed a linear barium-filled track at the left pyriform sinus. We report a case of actinomycotic thyroiditis in a young adult with pyriform sinus fistula along with a brief review of related literature. [ABSTRACT FROM AUTHOR]