Post-iodination Trends in Thyroid Pathology; 14-year Experience at a Single Center in a Goitre Endemic Area

Abstract

Introduction: Goitre is endemic in many parts of Sri Lanka. Universal iodination of salt was commenced in Sri Lanka in 1995 as a measure to reduce the prevalence. This study was designed to identify the pattern of thyroid pathology reported during a period of 14 years from 2002 to 2015 in a Pathology Unit serving the population in a goitre endemic area in Sri Lanka. Methods: This descriptive cross-sectional study included all thyroidectomy specimens histologically assessed at our unit from 2002 to 2015. Data on age, gender, clinical presentation, type of resection, and histopathological diagnosis were retrieved from the records. The trend of change in thyroid pathology over time was analysed by comparing 2002-2010 cohort (615specimens) with the 2011-2015 cohort (995 specimens). Results: This study included 1610 thyroidectomy specimens. Features of colloid goitre were present in 71.6% (1152/1610). Prevalence of chronic autoimmune thyroiditis and thyroid cancer was 41% (660/1610) and 15.3% (246/1610) respectively. There was no significant change in the gender and the age at presentation over the years. However, an upward trend in the prevalence of both focal and diffuse chronic autoimmune thyroiditis (p<0.001), hyperplastic nodules (p=0.008), papillary microcarcinoma (p<0.001), papillary carcinoma and colloid nodular goitre (p=0.004) was evident. Conclusions: Parallel increase in the prevalence of chronic autoimmune thyroiditis and papillary carcinoma together with the upward trend in the prevalence of colloid nodular goiter was evident.