A Comparative Study on Fine Needle Aspiration Cytology versus Fine Needle Capillary Cytology in Thyroid Nodules

Fine needle aspiration cytology (FNAC/FNA) is the primary investigation for thyroid nodules. Fine needle capillary cytology (FNCC/FNC) is an alternative technique not commonly used, though it is easy to perform. Both the techniques have their own advantages and disadvantages. This study aims to compare these two cytological techniques for better specimen and cytological diagnosis.

This prospective study was conducted on 50 patients attending the FR Muller Medical College Hospital from May 2006 to April 2008. The patients with thyroid nodules (diagnosed by palpation) were subjected to both the cytological techniques; FNA and FNC. The specimen and results were compared and then correlated with the final histopathological findings wherever surgical specimens were available (38 cases).

The mean age of the patients was 39.16 with a female predominance. The majority of cases were diagnosed to have nodular goiters. The FNC technique yielded 88% diagnostic superiority and adequate specimens compared to 94% by FNA. Sensitivity was 50% for FNC and 100% for FNA while specificity was 100% for both techniques; accuracy score was 97.4% for FNC and 100% for FNA in predicting malignancy. While sensitivity was 75% for FNC and 100% for FNA; specificity was 100% for both techniques, and accuracy score was 97.4% for FNC and 100% for FNA in the prediction of neoplasia.

The results indicated that there was no significant difference between the two techniques; if done in tandem can give better and accurate cytological diagnosis. In highly cellular lesions, in which abundant material was obtained, FNC was more likely to be diagnostically superior, but FNA can diagnose most of the lesions. In less cellular lesions, FNA is more likely to be diagnostically superior to FNC.