Lymphocytic thyroiditis (LT) embraces a heterogenous group of thyroiditis and Fine Needle Aspiration Cytology (FNAC) provides a safe and reliable method of diagnosing it. This present study was undertaken to analyze and grade Lymphocytic thyroiditis on cytology smears and compare the severity of thyroiditis with Thyroid Function Tests (TFT). Periodic assessment of Thyroid Function Tests and sub-classification of Lymphocytic thyroiditis on FNAC assists in early diagnosis of Lymphocytic thyroiditis and helps to monitor the progression of the disease state.
Materials and methods: This prospective study was conducted on 150 patients attending FNAC clinic at a tertiary level care hospital over a period of two years. Various parameters like Clinical signs & symptoms, Thyroid Function Tests, FNAC of thyroid gland, semi- quantitative grading on cytology smears were noted and results were analysed statistically.
Results: One hundred and fifty patients diagnosed as Lymphocytic thyroiditis on FNAC, showed a female predominance (96.7%) with a peak age group between 21-30 years. Clinically majority of them had a diffuse thyromegaly (88.0%) and 48.0% were biochemically hypothyroid. On sub-classifying cytology smears, Grade 1(mild) Thyroiditis was noted in 20%, Grade 2(moderate) in 64.0% and Grade 3(severe) in 16.0% of the cases. Few cases showed the presence of abundant colloid associated with LT in 22.0% of the cases. Positive Statistical association was seen between Grade 3 Lymphocytic thyroiditis and TSH levels (p=0.03), while Grade 1 & 2 of Lymphocytic thyroiditis did not show any correlation.
Conclusion: Despite the availability of several tests in diagnosing Lymphocytic thyroiditis, FNAC remains a gold standard test, especially in early stages of the disease. Co-existence of Lymphocytic thyroiditis & colloid is not unusual, particularly in post-iodization era.