Rates of lymphocytic thyroiditis and ultrasound features of citologically-interrogated thyroid nodules based on the area of residence in a Sicily province.

Purpose: To verify the prevalence of autoimmune thyroiditis (AIT) and the ultrasound characteristics (composition and volume) of thyroid nodules with respect to the area of residence in the province of Messina, some areas having environmental issues.

Methods: Fine-needle aspiration-interrogated nodules (n = 902) of 809 patients were evaluated upon stratification into 8 areas of residence.

Results: Overall, women were younger than men (55.3 ± 14.0 vs. 58.6 ± 12.6 years, P = 0.0083). Patients residing in three areas (one hosting two garbage dumps, one hosting a petrochemical complex and a thermoelectrical power plant, and one hosting several ceramic factories [CFA]) were younger than those residing in the city of Messina (MEA) (52.9 ± 13.4 vs. 57.7 ± 13.6 years, P < 0.0001). Also, patients residing in those three areas had a greater rate of AIT, diagnosed either ultrasonographically/serologically (22.2% of patients) or cytologically (26.3% of nodules), compared with MEA (11.7% of patients, P = 0.0007 or 20.2% of nodules, P = 0.0815). Rates of AIT ranged 12.5-28.6% in the remaining four areas. Overall, nodules in women were smaller than in men (3.6 ± 5.7 vs. 6.1 ± 9.4 ml, P = 0.0006). Compared with the other seven areas, patients living in CFA had the largest nodules (6.8 ± 6.8 ml, P = 0.0040-0.0291), with the nodule volume being inversely correlated to patient's age (r = -0.4955, P = 0.0431).

Conclusion: Rates of AIT and associated ultrasound features of thyroid nodules vary in different areas of our province. Further studies correlating these rates and features with exposure to specific toxicants are warranted.