Fine needle aspiration biopsy cytology in the diagnosis of thyroid cancer: Comparative study of 213 operated patients

Between 1982 and 1984, fine needle aspiration biopsy cytology (ABC) was performed in 1100 patients (aged 14–80, 993 women), with nodular goitre, who had either a solitary cold nodule or dominant hypofunctioning nodule(s) within a multinodular or diffusely enlarged gland. Surgery was performed in 213 patients based on clinical and cytological criteria, and the histology of the surgical specimens was correlated with the cytological findings. ABC specimens were sufficient for cytological diagnosis in 190 patients and were classified as malignant (positive), suspicious or benign. In 37 patients who had a final histological diagnosis of malignancy, cytology was positive or suspicious in 33 and benign in 4. In the remaining 153 patients with benign histology there were 7 positive or suspicious aspirates, and 146 benign. The 37 malignancies included papillary carcinomas in 26 patients (24 positive or suspicious and 2 benign on cytology), Hürthle‐cell tumours in 6 (6 positive), follicular carcinoma in 1 (negative), anaplastic carcinoma in 1 (suspicious), medullary carcinoma in 2 (1 positive, 1 negative), and lymphoma in 1 (positive). Our results indicate that the overall sensitivity rate of the ABC method for cancer was 89.2 per cent, the diagnostic specificity 95.4 per cent, the false‐positive rate 17.5 per cent and the false negative rate 2.6 per cent. The overall accuracy of the method was 94.2 per cent. It is concluded that papillary and Hürthle‐cell carcinomas can be diagnosed accurately with ABC but we recommend that the method be used in conjunction with clinical information and other conventional diagnostic procedures.