Abstract
BACKGROUND: Recent studies suggest that the encapsulated form of follicular variant of papillary thyroid cancer (eFVPTC) behaves more similarly to benign lesions and can be treated with thyroid lobectomy alone instead of total thyroidectomy. To distinguish aggressive cancers from more benign lesions more clearly, the objective of this study was to determine if the eFVPTC behaves less aggressively than the nonencapsulated variant (neFVPTC). METHODS: A prospectively collected endocrine surgery database in our institution was reviewed for all patients with FVPTC on surgical pathology from 1999 to 2012. Samples were rereviewed to determine if the tumor was eFVPTC or neFVPTC, which were correlated with patient outcomes. RESULTS: Of the 68 patients, 59 (87%) had eFVPTC and 9 (13%) had neFVPTC. The mean age was 48 y and 63% were female. Fifty-four of 64 patients (84%) who had a total thyroidectomy received radioactive iodine. The eFVPTC group had lower rates of cervical LN involvement (5% versus 22%, P = 0.2504). The median follow-up time was 3 y (0-13 y) and only two patients had recurrence, one with eFVPTC and one with neFVPTC. None of the patients had distant metastasis or died of their disease. CONCLUSIONS: eFVPTCs appear to have a lower rate of cervical lymph node metastases compared with neFVPTCs, but recurrent disease may be seen in both subtypes. These findings suggest eFVPTC can be managed more conservatively.