Z. Aburjania3, D. Elfenbein4, E. Weinlander4, C. Montemayor5, R. Lloyd5, D. Schneider4, R. Sippel4, H. Chen3 3University Of Alabama,Department Of Surgery,Birmingham, Alabama, USA 4University Of Wisconsin,Department Of Surgery,Madison, WI, USA 5University Of Wisconsin,Pathology,Madison, WI, USA
Introduction: Follicular variant papillary thyroid cancer (FVPTC) is a well differentiated thyroid cancer thought to be slightly more aggressive than papillary thyroid cancer. Total thyroidectomy is the common treatment for FVPTC. However, recent studies suggest that the encapsulated form of FVPTC (eFVPTC), a subtype reported to behave more like a benign lesion, can be treated with thyroid lobectomy alone. The objective of this study was to determine if the eFVPTC behaves less aggressively than the non-encapsulated variant.
Methods: A prospectively collected endocrine surgery database was reviewed for all patients with either type of FVPTC on surgical pathology between 1999-2012. Histology was re-reviewed by a pathologist to determine if the FVPTC was encapsulated (eFVPTC) versus non-encapsulated (FVPTC).
Results:Of the 68 patients with FVPTC, 27(40%) had eFVPTC while the remaining 41(60%) had FVPTC. The mean age was 48 ± 1.8 years and 63% were female. Sixty-four (94%) underwent total thyroidectomy while the remaining patients had thyroid lobectomy alone. Fifty-four (84%) patients who had a total thyroidectomy received radioactive iodine. In comparing the groups, eFVPTC was more common in females than in males (49% vs. 24%, p=0.043). Five (7%) patients had cervical lymph node (LN) involvement, and the mean age of those patients was 34 ± 2.3 years compared with the patients without (vs 49.9 ± 6.8, p < 0.0001). The eFVPTC group had lower rates of cervical LN involvement (4% vs 10%, p=0.6411). Patients were followed for median of 3 years (range: 0-13). Recurrence occurred in only 2 patients: one with eFVPTC and one with FVPTC. None of the patients had distant metastasis and no patients died of their disease.
Conclusion: Encapsulated FVPTCs appear to have a lower rate of cervical lymph node metastases compared to non-encapsulated tumors, but recurrent disease may be seen in both subtypes of FVPTCs.