Micronodularity is an important physical sign in chronic autoimmune thyroiditis

Abstract

INTRODUCTION AND OBJECTIVES: Chronic autoimmune thyroiditis is the commonest inflammatory disorder of the thyroid. There is evidence that the prevalence of autoimmune thyroiditis is increasing in Sri Lanka. The clinical features of autoimmune thyroiditis have been described in text but micronodularity which is found frequently has not been well documented as a physical sign. Aim of this study was to assess whether micronodularity is an important physical sign in clinical diagnosis of chronic autoimmune thyroiditis. METHODS: Analysis of physical characteristics of goitres in 426 patients who were part of an island wide study on epidemiology of goitre. All physical characteristics were taken note of and micronodularity was taken as a screening test compared with biochemical and cytological evidence of chronic autoimmune thyroiditis.RESULT: From 5200 participants (mean age = 36.3 years) goitres' were detected in 426 participants (143 males, 283 females). Modularity was detected in 271. Micronodularity was present in 190 (70.1 %) whereas macronodularity was detected in 81 (29.9 %). Thyroid antibody status was available in 153 participants where 74 had micronodularity. 27 with micronodularity were test positive (sensitivity - 49.09% / specificity = 52.04% 7PPV = 36.48%/NPV = 64.55%). Cytology was available in 328 subjects where 146 had micronodularity. 54 with micronodularity were cytologically positive (sensitivity = 47.79% and specificity = 57.21% / PPV = 36.98% / NPV = 67.58%). CONCLUSIONS: Diagnosis of chronic autoimmune thyroiditis is based on clinical, biochemical and cytological evidence. Micronodularity is a useful physical sign in diagnosing chronic autoimmune thyroiditis