Fine-needle aspiration biopsy specimen with a predominance of Hurthle cells: A dilemma in the management of nodular thyroid disease

Background. A fine-needle aspiration biopsy (FNAB) specimen of a thyroid nodule with a predominance of Hurthle cells usually is indicative of a Hurthle cell neoplasm, but it also may occur with nonneoplastic disease. Methods. A prospective nodular thyroid disease database was used to identify patients with a FNAB specimen consisting of a predominance of Hurthle cells. Clinical factors were investigated and FNAB specimens were examined in a blinded fashion by a single cytopathologist to determine if there were specific factors that could be used to distinguish nonneoplastic from neoplastic disease. Results. Of the 738 patients with nodular thyroid disease, 622 had a FNAB specimen. The FNAB specimen was interpreted as consistent with a Hurthle cell neoplasm in 45 (7%) patients, 7 (16%) with carcinoma, 21 (47%) with adenoma, 12 (27%) with adenomatous hyperplasia, and 5 (11%) with thyroiditis. Extensive cellularity and absent colloid were associated with neoplastic disease (p < .05). No cytologic feature reliably excluded neoplastic disease (P > .05). No significant differences in age ((x) over bar +/- SD) (51 +/- 17 vs 54 +/- 17 y), sex (female/male ratio, 611 vs 1512), nodule size (3.9 +/- 1.9 vs 3.4 +/- 2.0 cm), weight of excised thyroid tissue (42 27 vs 33 30 g), or functional status of the thyroid gland was observed between patients with neoplastic (n = 28, 62 %) versus nonneoplastic (n = 17, 38 %) disease. Conclusions. Neoplastic disease accounts for two thirds of the pathology in patients with a predominance of Hurthle cells on FNAB specimen and neither clinical nor cytologic features reliably exclude Hurthle cell adenoma or carcinoma. As a result, thyroidectomy is recommended for all patients with a thyroid nodule and a predominance of Hurthle cells on FNAB specimen.