Introduction: Chronic lymphocytic thyroiditis (CLT) is included in non-neoplastic thyroid lesions. These are autoimmune disorders characterized by inflammation of thyroid with variable clinical features of altered thyroid function. It has prevalence rate of 1-4% and incidence of 30-60/100000 population per year. It is more common in middle aged women. There is rise in the incidence and diagnosis of CLT due to iodine supplementation of diet and improved diagnostic techniques respectively.

Aims and Objectives: To study clinical presentation and cytological parameters of CLT in detail and study these parameters with respect to cytological grades.

Material and Methods: Total 313 cases of CLT diagnosed on cytology were included in the study. FNAC was done using non-aspiration technique. All the cases were analysed for age, sex and clinical presentation. Cytological parameters were studied in detail and based on these parameters, cases were graded as per Bhatia et al’s criteria.

Results & Discussion: Clinically all the cases presented with anterior neck swelling, followed by hypothyroid and hyperthyroid symptoms. Amongst cytomorphological parameters, background lymphocytes were noted in all 3 grades with varying percentages of other parameters.

Conclusion: Clinical presentation of lymphocytic thyroiditis varies depending on the stage of disease, but careful evaluation of all cytological parameters can make correct diagnosis of CLT.

Keywords: Chronic Lymphocytic Thyroiditis; FNAC; Lymphocytes.