A long term clinical, immunological, and histological follow-up study of patients with goitrous chronic lymphocytic thyroiditis.

Goiter size, thyroid function, antimicrosomal and antithyroglobulin antibodies, and thyroid histology were compared in 43 patients with goitrous chronic lymphocytic thyroiditis (Hashimoto's disease) confirmed by biopsy before and after an interval of 10-20 yr. Although all were given thyroid hormone therapy, 13 patients took it infrequently, and are considered untreated. Among these 13 patients, 5 (38%) became hypothyroid, and 1 became thyrotoxic. Goiter size decreased in 17 (57%) of 30 patients during therapy and in 3 (23%) of 13 untreated patients, and the incidence of reduction was greater in treated than in untreated patients (P less than 0.05). However, in 13 (43%) of the patients, goiter size did not decrease even during treatment. Titers of antithyroid antibodies decreased in only 8 (21%) of 38 patients. There was no significant correlation between changes in antibodies and the size of goiter, and treatment with thyroid hormone did not decrease the titers of antibodies. In patients whose goiters were initially diffusely enlarged and regressed significantly in size during the follow-up period, the initial biopsies showed histological changes in diffuse lymphocytic infiltration and diffuse epithelial changes. Comparative studies of histological differences between patients who were treated with thyroid hormone and those who were not were made in the patients who had no change in goiter size during the observation period, which was greater than 10 yr. The histological changes were similar in both groups at the beginning of the study, and no significant histological changes during the period of greater than 10 yr were found in either group. In one patient who developed thyrotoxicosis after 20 yr and was rebiopsied, the histological picture was that of thyroid hyperplasia and lymphocytic thyroiditis. These data indicate that goitrous chronic lymphocytic thyroiditis changes little as a function of time in many patients regardless of whether thyroid hormone is administered.