Chronic autoimmune thyroid disease.

A total of 67 patients with chronic autoimmune thyroid disease were followed, mainly as outpatients, for a period of a few months to over 15 years. The diagnosis was euthyroidism (n = 16, 23.8%), subclinical hypothyroidism (n = 20, 29.8%), primary hypothyroidism (n = 28, 41.7%) or hashitoxicosis (n = 3, 4.47%). Patients with goiters fit Hashimoto's original description of "struma lymphomatosa". The diagnosis was made on clinical grounds and the usual laboratory hormonal tests. Histological examination was carried out at surgery or by fine needle aspiration in 35 patients (52.2%), and a clinical diagnosis was made in 32 (47.7%). Three patients had juvenile Hashimoto's thyroiditis. Most patients were in the fourth, fifth or sixth decade (64.8%), and of these 12 (18%) had subclinical hypothyroidism, which should be suspected when thyrotropin (TSH) is twice the upper normal limit. In these cases thyrotropin releasing hormone (TRH) testing and evaluation of anti-thyroglobulin antibodies (TgAb) and anti-microsomal antigen antibodies (MsAb) are mandatory. Hypothyroidism with few symptoms develops insidiously in young or elderly patients; the most sensitive test is TSH assay in conjunction with tests for TgAb and MsAb. L-thyroxine administration may be harmful in older patients with late diagnosed primary hypothyroidism. Thyroid supplementation is suggested for patients with subclinical hypothyroidism if TSH values are above 10 mU/L; otherwise they should be followed up annually, as should patients with positive thyroid autoantibodies who are still euthyroid.