The outcome of benign thyroid nodules correlates with the findings of fine needle biopsy.

Abstract

204 patients with a single or dominant 'cold' thyroid nodule were treated with l-thyroxine, 150-250 micrograms/d, for 4 to 12 months. The two clinicians who evaluated the evolution of the nodules knew that fine-needle biopsy (FNB) had excluded malignancy, but ignored any other morphologic data of the FNB smears. Good outcome, i.e. disappearance of the nodule or definite decrease in its size, was observed in 66 cases (32%). This good clinical outcome was correlated with various morphologic characteristics of the FNB aspirate. The nodule was more likely to regress if FNB showed much colloid, many degenerative changes and many phagocytes, whereas the presence of extensive hyperplasia, lymphocytes or fibrosis were associated with an unfavourable prognosis. With logistic regression, controlling for the confounding effects of sex, age, clinical and histological picture and thyroxine dose, significant correlations were shown with the presence of colloid, hyperplasia and fibrosis. It is concluded that the morphologic characteristics of the FNB aspirate may, to some extent, predict the outcome of cold thyroid nodules.