Fine needle aspiration cytology as the primary diagnostic tool in thyroid enlargement

Background: In the preoperative decision-making of the thyroid swellings, fine needle aspiration cytology (FNAC) is becoming an ever more vital tool.

Objectives: To compare the advantage of preoperative FNAC of thyroid swellings with postoperative histopathology to reach a consensus protocol as a simple procedure for diagnosis and optimal management of thyroid swellings.

Materials and methods: A prospective study of preoperative FNAC was carried out on 178 incidental thyroid swellings attending a tertiary care centre in Kishanganj, Bihar. Evidence-based surgical interventions were done, irrespective of FNAC findings and diagnosis was confirmed by histopathological examination (HPE) postoperatively in all the cases.

Results: In the FNAC, preponderance of the cases (75.84%) was colloid goitre followed by granulomatous thyroiditis; follicular carcinoma was noted in 7.30 percent and anaplastic carcinoma in 3.37 percent of cases. Histopathological examination showed colloid goitre predominantly (76.97%), followed by follicular carcinoma (8.99%). The overall prevalence of malignancy was 11.24 percent diagnosed by HPE and 9.55 percent by FNAC. In our FNAC series sensitivity of was 90 percent while specificity was 100 percent; accuracy was 98.88 percent. Predictive value of a positive test and negative tests was 100 percent and 98.75 percent respectively.

Conclusion: The study highlights that FNAC should be treated as a first-line diagnostic test for thyroid swellings to guide the management though this is not a substitute for HPE as a need to improve primary healthcare in India.