THYROTOXICOSIS (HYPERTHYROIDISM) - Toxic nodular Goiter



This common cause of hyperthyroidism in the elderly generally occurs in patients with a long history of nodular goiter, but only a few patients with nodular goiter develop hyperthyroidism. It is not clear why these few nodular goiters progress to the toxic state and become autonomous in func­tion. These patients generally present with symp­toms and signs referable to the cerebrovascular, cardiovascular, musculoskeletal, or gastrointes­tinal system. Their hyperthyroidism is frequently masked by the nonthyroidal manifestations so that the true diagnosis is often delayed. Elderly patients with nodular goiter should be screened for thyroid dysfunction whenever they present with features of a new illness. The majority of these hyperthyroid patients will have an unequiv­ocal increase in serum total and free T4 values. Since 10 to 15 per cent may have normal T4 values but a high serum T3 concentration (T3 toxicosis), the latter measurement should always be in­cluded when hyperthyroidism is clinically sus­pected in the elderly patient.

The majority of these patients can be treated with 131I, but the effective dose generally ranges from 15 to 30 mCi. Hypothyroidism follows less frequently than in Graves’ disease. It is preferable to induce a euthyroid state with antithyroid drugs prior to definitive therapy in order to avoid ag­gravation of the thyrotoxicosis. Surgery may be . indicated in individuals with very large goiters (>100 grams) and in those patients who have pressure complications from goiter.