Does Hurthle cell lesion/neoplasm predict malignancy more than follicular lesion/neoplasm on thyroid fine‐needle aspiration?

AbstractThyroid fine‐needle aspiration (FNA) is a standard procedure for the clinical triage of thyroid nodules. The diagnosis of an adequately sampled thyroid FNA is generally grouped into three categories: benign, malignant, and indeterminate. The latter group usually includes follicular neoplasm, follicular lesion, and sometimes a more specific diagnosis such as Hurthle cell neoplasm or follicular lesion/neoplasm with Hurthle cell change. Whether a FNA diagnosis of Hurthle cell lesion/neoplasm (HLN) denotes a worse clinical outcome than follicular lesion/neoplasm (FLN) remains controversial. A cohort of 303 thyroid FNA cases with follow‐up thyroidectomy in our institutes was identified, with the follow‐up excision diagnosis compared to the FNA diagnosis in order to address this issue. Of this cohort, 87 cases had an FNA diagnosis of HLN while 216 cases had a diagnosis of FLN. Upon excision, the FNA diagnosis of HLN group had 14 cases of goiter/nodular hyperplasia (16%), 46 cases of adenoma (12 follicular adenoma (14%) and 34 cases of Hurthle cell adenoma (39%)), and 27 cases of carcinoma (31%, 12 papillary carcinoma and 15 Hurthle cell carcinoma). The FLN group had 74 cases of goiter/nodular hyperplasia (34.3%), 8 cases of Hashimoto thyroiditis (3.7%), 73 cases of follicular adenoma (33.8%), one case of granular cell tumor, and 60 cases of carcinoma (27.8%, 46 papillary carcinoma, 12 follicular carcinoma, and 1 Hurthle cell carcinoma and 1 parathyroid carcinoma) upon excision. There is no significant difference in predicting cancer between the two cytology diagnosis groups (HLN versus FLN, 31% versus 27.8%, P = 0.5771). When sorting all the cases by the surgical diagnosis, while comparable for age at diagnosis, the cancer group having the higher proportion of male patients than the non‐cancer group (28.7% versus 16.7%, P = 0.0259). Hurthle cell carcinoma patients are typically older than patients with other cancer diagnoses (59 versus 44, P = 0.0077). Our results suggest that an FNA diagnosis of HLN does not predict more malignancy than FLN. Males and older patients with a HLN FNA diagnosis carry a higher risk of Hurthle cell carcinoma upon thyroidectomy. Diagn. Cytopathol. 2006;34:330–334. © 2006 Wiley‐Liss, Inc.