Granulomatous Thyroiditis (De Quervain's Thyroiditis)*

GRANULOMATOUS thyroiditis is a distinct clinicopathologic entity, apparently a true nonsuppurative inflammation of the thyroid gland, that can be distinguished from the rare invasive fibrous thyroiditis (Riedel's struma) or the more common struma lymphomatosa. Since its first description by de Quervain in 1904 (1), the disease has been reported under many synonyms. Terms that call attention to the histologic features of the lesion include “pseudotuberculous thyroiditis,” “granulomatous thyroiditis,” “giant-cell thyroiditis” or “struma fibrosa, giant-cell variant.” The clinical findings have given origin to such names as “acute and subacute nonsuppurative thyroiditis,” “acute noninfectious thyroiditis,” “acute diffuse thyroiditis” and “subacute thyroiditis.” The latter term is commonly used. However, since there appears to be one basic pathologic process with extreme variation in severity of symptoms, and since many cases undoubtedly occur in which subjective symptoms are absent, it was thought best to use the name that calls attention to the distinctive pathologic findings, namely “granulomatous thyroiditis.”