[Autonomous thyroid nodule: relations between clinical symptomatology and goiter endemia]

Sixty-three patients with autonomous thyroid nodule were studied, thirty-five from an endemic goiter area (EA) and twenty-eight from a non-endemic goiter area (NEA). Clinical history, physical examination, ultrasonography, thyroid hormone levels, and fine needle aspiration (FNA), were utilized to investigate whether or not iodine deficiency determined differences in the latency of progression to toxicity, the seriousness of illness and thyroid hormone levels. No significant difference was observed in the age of onset of nodularity, while the latency of progression to toxicity was significantly decreased in the EA (p less than 0.001). The ultrasonographic pattern did not show significant volume variations between the EA and NEA, but there was a slight prevalence of multinodular lesions in EA. No significant difference in serum thyroid hormone levels was found between the two areas in non toxic patients, while at the onset of hyperthyroidism higher levels of FT were observed in the EA than in the NEA. FNA showed a prevalence of colloid lesions in EA, while hyperplastic lesions prevail in the NEA. Forty-two patients underwent surgery: the extent of surgery was greater in patients from the EA. In conclusion, in iodine deficient areas earlier clinical thyrotoxicosis and a higher prevalence of hypoactive thyroid nodules were observed. Furthermore, in EA, the autonomous nodule in non toxic phase is more frequently associated with colloid lesions than hyperplastic lesions.