Background: The influence of clinicopathologic features on prognosis of papillary thyroid cancer has been examined. However, the relationship between cytologic features obtained by fine-needle aspiration (FNA) and prognosis has been minimally studied.
Methods: We retrospectively studied 85 patients with usual-type papillary thyroid cancer diagnosed by FNA who underwent total or near-total thyroidectomy, had disease confirmed by pathological study, and were followed for more than 10 years except for one patient with metastasis at diagnosis. Cytologic features of FNA and recurrence of cancer were examined statistically.
Results: Four cytologic features were significantly related to recurrence: bigger nuclei, more irregularly shaped nuclei, nuclear atypia, and simultaneous presence of lighter staining nuclei and apparent nucleoli. A prognostic score of 1 (light nuclei and apparent nucleoli) plus 1.5 (irregularly shaped nuclei away from fibrous cord) plus 1 (high nucleus-to-cytoplasm ratio) plus 1 (nuclear atypia) was generated statistically. Sensitivity and specificity using a cut point of 2.5 in predicting outcome were 83.33% and 77.55%, respectively.
Conclusions: Cytologic features of FNA samples have prognostic significance. If the prognostic score of cytologic features is high, a more radical surgical procedure and aggressive treatment plan should be considered.