Background: Fine-needle aspiration biopsy (FNAB) and frozen section exam are of limited or no value in distinguishing benign and malignant follicular or Hürthle cell neoplasms of the thyroid gland.
Methods: Patients who underwent thyroidectomy for treatment of a follicular or Hürthle cell neoplasm between 1990 and 1998 were identified and evaluated for age, gender, head and neck irradiation, nodule size, and cytologic atypia to determine whether clinical factors were predictive of carcinoma.
Results: Of the 352 patients evaluated for nodular thyroid disease, 75 (21%) underwent thyroidectomy after an indeterminate FNAB finding, 66 with follicular and 9 with a Hürthle cell neoplasm. Seventeen (23%) of the patients had carcinoma-follicular variant of papillary (10), follicular (6), and Hürthle cell (1). Carcinoma was diagnosed in 15 of 64 women and 2 of 11 men (P > .05). The mean age was 43 +/- 21 years and 50 +/- 16 years, respectively, in patients with and without carcinoma (P > . 05). Three patients had previous neck irradiation and none had carcinoma. Mean nodule size was 4.2 +/- 2.7 cm and 4.3 +/- 3.5 cm, respectively, in patients with and without carcinoma (P > . 05). Cytologic atypia was present in 8 of 17 patients with carcinoma and 20 of 58 patients without carcinoma (P > .05).
Conclusions: Clinical factors were not helpful in predicting carcinoma in patients with an indeterminate FNAB finding and thus cannot be used to reliably select patients for more extensive thyroidectomy.