Clinicopathological correlation of serum TSH in patients with thyroid nodule

Abstract

Thyroid nodules and goitre are common. Carcinoma occurs in 5% of thyroid nodules. Early detection and treatment is beneficial to prolonged survival. Higher thyroid stimulating hormone (TSH) level in patient with thyroid nodule is associated with greater risk of differentiated thyroid carcinoma. To assess relationship of TSH with thyroid carcinoma in nodular goitre and usefulness of this marker in predicting likelihood of thyroid malignancy, a study was undertaken among patients with nodular goitre enrolled prospectively during the period 2007 to 2009. Clinically thyroid nodules, confirmed by high resolution USG underwent serum TSH estimation and FNAC of the the nodules. Finally outcome of histopathological examination of resected thyroid specimen were analysed. Overall 33 patients with thyroid nodules were included in this study. Fifteen patients belonged to age group of 31 to 40 years, 13 belonged to 21 to 30 years; 29 were women, 4 were men. Majority of nodules were in right lobe and firm or hard. Fifteen nodules were > 4cm in size. FNAC showed colloid goitre in 24 patients, 7 patients had papillary carcinoma, 2 patients had follicular nodule. Final histopathological report showed 9 papillary carcinoma, 1 medullary carcinoma, 1 follicular carcinoma, 2 follicular adenoma and rest being colloid goitre. Mean TSH value for colloid goitre was 1.8987 mlU/l, for papillary carcinoma it was 2.2400 mlU/l, for follicular carcinoma it was 2.8900 mlU/l, for medullat carcinoma it was 0.8500 mlU/l and for follicular adenoma it was 4.4200 mlU/l. In differentiated thyroid carcinoma TSH value is raised more than in colloid goitre (p = 0.687). Incidence of malignancy in nodular goitre was 30% (11 carcinoma out of 33) in this study. Incidence of malignancy in nodular goitre is rising. Firm to hard nodules, male sex, 3-4 cm sized nodules are mainly susceptible. There is an obvious trend towards cancer risk with higher TSH value. TSH may, therefore, be used as a supportive screening test to predict malignancy in patients with thyroid nodule.