Comparison of Malignancy Rate in Thyroid Nodules with Cytology of Indeterminate Follicular or Indeterminate Hürthle Cell Neoplasm

Abstract

There is little difference in the rate of malignancy between thyroid nodules with a cytological reading of FN indeterminate for malignancy and HN indeterminate for malignancy but there is a difference in the types of thyroid cancers in these groups. Hürthle cell thyroid cancer and the oncocytic variant of PTC is more common in nodules with an HN indeterminate for malignancy cytology reading than in nodules with a FN indeterminate for malignancy cytology reading. Since Hürthle cell thyroid cancer and the oncocytic variant of PTC are more aggressive than other thyroid cancers, it is likely that patients with an HN indeterminate for malignancy cytology will, as a group, have more aggressive thyroid cancers than those with an FN indeterminate for malignancy cytology.