[The spontaneous course of compensated autonomous thyroid gland adenomas]

The spontaneous course of 58 patients with compensated autonomous adenoma of the thyroid was followed. Scintigraphic appearance (compensated (CAA) or decompensated (DAA)) was documented and the serum levels of thyroxine (T4), triiodothyronine (T3) and thyroid-stimulating hormone after TSH-stimulating hormone were measured at the beginning of observation and 3.8 years (median) later. During follow-up period, 13 patients (22%) with CAA developed DAA. 9/13 patients (15%) had overt hyperthyroidism with elevated T4 and/or T3 levels, 4/13 patients (7%) had normal thyroid hormone levels. Life table analysis showed a risk for developing hyperthyroidism of 19% at five years. The size of all adenomata measured scintigraphically was increasing during follow-up, and there was no discrimination of CAA from DAA using this technique. Eight CAA patients received iodinated contrast medium but none develop DAA. In conclusion from these results as well as from the literature, there is no indication for surgery or radioiodine therapy of patients with a CAA, even if there are plans to administer iodinated contrast medium.