Role of FNA in the medical management of minimally enlarged thyroid

Fine-needle aspiration (FNA) of thyroid is a cost-effective and simple diagnostic tool in the initial screening of patients with thyroid nodules. But, its role in a clinically normal thyroid or a minimally enlarged thyroid in a symptomatic patient suspected of having thyroid dysfunction is unknown. With our 2-yr experience in a setup of a tertiary health care hospital in a developing country, we have aimed to implement a management protocol using FNA thyroid done without ultrasound guidance and TSH estimation done during the same visit in symptomatic patients suspected of having thyroid pathology but presenting with no goiter or having minimally enlarged thyroid with no palpable nodules. The thyroid enlargement in 172 cases were graded with the criteria endorsed by WHO, Pan American Health Organization, and International Council for Control of Iodine Deficiency Disorders into grade 0, 1, and 2. The cases were evaluated cytologically and correlated with TSH values according to the algorithm formulated by the authors. FNA was diagnostic in 86.6, 98, and 100% in grade 0, 1, and 2 goiters, respectively. 52.3% (n = 90), 19.8% (n = 34), 16.9% (n = 29) of cases were diagnosed as Hashimoto's thyroiditis (HT), colloid goiter (CG), and lymphocytic thyroiditis (LT). Sixteen had a combination of LT and CG (n = 6), HT and CG (n = 6), papillary carcinoma (n = 2), and diffuse hyperplasia (n = 2). No statistically significant difference (P = 0.4586) was noted between the groups of patients with grade 0 and grade 1-2 goiter, who underwent FNAC. 38.95% of patients (n = 67) with TSH values greater than 10 microIU/ml and considered hypothyroid showed features of HT/LT at FNA. 23.83% (n = 41) having TSH values between 5 and 10 microIU/ml (subclinical hypothyroidism) also showed features of HT/LT at FNA. Both groups were treated with thyroxine. 35.46% (n = 61) of cases with TSH values within normal range (0.5-5.1 microIU/ml) and considered euthyroid showed a spectrum of lesions at cytology other than HT and LT. They are being followed up to detect them at an early stage of subclinical hypothyroidism. Only 13 cases (7.5%) who were serologically euthyroid showed HT/LT and are being followed-up. Thus, the authors advocate FNA of the thyroid as a single simple cost-effective office procedure in the medical management of all nonpalpable/minimally enlarged thyroid in patients suspected of having thyroid pathology and/or in combination with TSH values. FNA helps in early detection of subclinical hypothyroidism, which is of utmost importance in pregnant women and further makes possible availability of baseline values for future reference. With the implementation of this protocol of FNA thyroid without imaging, we affirm that the practice of cytology which differs in different geographic areas and from country to country depending on economy and availability of infrastructure can be made more user-friendly.