[Hashimoto's lymphomatous thyroiditis and endemic struma]

Hashimoto's thyroiditis, a rather rare disease in endemic goiter areas like Switzerland, seems to become more frequent under iodine prophylaxis. To obtain more precise data we reviewed the microscopic slides of surgical thyroid specimens with indications of any type of inflammation from two 10-year periods with respectively lower (1940-1949) and higher (1973-1982) iodination of salt. From 1940-1949 Hashimoto's disease was never diagnosed histopathologically. A review of the histological slides, however, showed typical signs of Hashimoto's disease in 9 out of 6836 thyroid specimens, or 0.13%. In the second period, from 1973-1982, the same diagnosis was established in 32 of 4088 thyroid specimens, or 0.78%. This 6-fold increase in frequency of Hashimoto's disease seems to be due in part to a real increase, and in part to a change in the surgical material. At present fewer nodular goiters are seen than in the first period. Inflammatory infiltration in Hashimoto's disease, however, involves not the nodule but the non-nodular thyroid tissue found to a larger extent in present-day thyroid surgical specimens.