Hürthle-cell neoplasms of the thyroid gland.

The difference in biologic behavior of Hürthle-cell neoplasms as reported in several series may be explained by the use of different diagnostic pathologic criteria, and the selection of patients with neoplasms of varying clinical stages (treatment at the time of initial diagnosis versus treatment for advanced disease, or initial diagnosis at an advanced stage). On the basis of all of the available evidence, it appears that Hürthle-cell neoplasms exhibit a biologic behavior similar to that of corresponding follicular neoplasms although these latter tumors may have a slightly higher propensity to metastasize. Survival and cure rates are lower than those for papillary cancer and are comparable to those for follicular carcinoma. DNA analysis may be of some help in predicting clinical behavior; aneuploid neoplasms are more often associated with the pathologic features of malignant tumors and may follow a more aggressive clinical course. At present, however, we are unaware of specific surgical strategies that are based upon DNA analysis. Tumor size and morphometric analysis of cytological features have not been particularly valuable for estimating the clinical course of these tumors.