An analysis of thyroid cytology reporting in three peripheral hospitals in Sri Lanka

Thyroid cytology is a widely used, cost effective outpatient procedure, which can be easily utilized in resource limited peripheral hospitals, available for preoperative assessment of thyroid nodules. We conducted the following study to analyze thyroid cytology reporting in three peripheral hospitals in Sri Lanka to assess their diagnostic utility, identify the associated problems and make recommendations for further improvement. This was a retrospective study performed on 300 thyroid cytology cases with a histological diagnosis. Thyroid cytology was reported according to BTA/RCP guidelines. Of the cytology diagnosis categories 72.7% were Thy 2, 22.3% were Thy 3, 4.7% were Thy 4 and 0.3% were Thy 5 lesions. Malignancy detection rate for each category were 2.3% for Thy 1, 13.4% for Thy 2, 64.3% for Thy 3 and 100% for Thy 4. The test had a 66.7% sensitivity, 97.7% specificity, 66.8% positive predictive value and 97.7% negative predictive value in diagnosing a malignancy. These parameters are comparable with the published parameters. However, the sensitivity of the test in the three hospitals showed significant variability. Concerted use of clinical and ultrasound findings in the interpretation of smears and multidisciplinary team meetings to discuss equivocal cases can be used to improve the diagnostic utility of thyroid cytology in these hospitals. Furthermore, performance of regular internal audits for each institution to identify problems is important since the study has shown variations in diagnostic parameters in different hospitals.