Cold thyroid nodule reduction with L-thyroxine can be predicted by initial nodule volume and cytological characteristics.

In a previous study we demonstrated that a 1-yr treatment with L-T4 induces substantial nodule volume reduction (> or = 50%) in approximately 40% of patients with a benign solitary cold thyroid nodule. The present prospective study investigated whether it is possible to identify, before starting L-T4 treatment, nodules with a high probability to shrink in response to L-T4. We recorded several clinical and cytological features in a continuous series of 42 patients with a cold nodule and related them to the nodule volume response to 1-yr treatment with L-T4. Fisher discriminant analysis showed that a combination of some cytological features (colloid, degenerative changes, cellular hyperplasia, and fibrosis) and initial nodule volume can be used for predicting nodule volume reduction. In fact, although only 33% of all nodules shrank, 62% of colloid nodules and 57% of small degenerative nodules shrank. None of the hyperplastic or fibrotic nodules shrank. These results were validated in a different retrospective series of 46 patients and allowed us to predict nodule reduction in over 80% of the cases.

Longitudinal study on goiter prevalence and goitrogen factors in northeastern Sicily.

A longitudinal study was carried out in an area of endemic goiter of north-eastern Sicily. Three different surveys (in 1977, 1983 and 1994) evaluated the epidemiological prevalence of goiter in schoolchildren of the endemic area (towns of Bronte, Troina and Maniaci) in comparison to an iodine sufficient control area (Catania). Biochemical studies were also performed on urinary iodine and thiocyanate (SCN) excretion and 131I thyroid uptake. In the town of Troina an experimental program of active iodine prophylaxis was carried out from 1979 to 1987 by iodinating the municipal water supply. The aim of this study was to evaluate the effect of an active iodine prophylaxis program in comparison to the "silent iodoprophylaxis" due to improved economic conditions and widespread introduction of industrially produced food. In the 1977-94 period a significant decrease of goiter prevalence in schoolchildren was observed in all areas where no active iodoprophylaxis had been introduced. An abnormal prevalence of goiter, however, was still present in Bronte (12.1%) and Maniaci (25.9%) schoolchildren in respect to Catania (0.7%). In Troina, goiter prevalence decreased from 52.2 to 6.1% after only five years of active iodine prophylaxis (1983). It increased to 8.4% seven years after the program was discontinued (1994). In all areas studied average urinary iodine excretion increased by 70-100 micrograms/day except in the more rural area at Maniaci. During the same period urinary SCN values decreased by 30-40% and were lower in Troina (non volcanic soil) than in other towns studied. The balance between iodine and SCN intake appears a relevant factor in the etiology of endemic goiter in these areas and the iodine/SCN ratio inversely correlated with goiter prevalence. The persistence of endemic goiter in spite of the important changes in life style and socio-economic conditions if compared to the dramatic amelioration obtained by an active iodine prophylaxis program, confirms the inadequacy of the silent iodine prophylaxis, and further supports the need of an immediate introduction of active iodine prophylaxis in the areas of endemic goiter in Sicily.