Lee, Inhwa1; Kim, Hyeung Kyoo2; Lee, Jeonghun3; Soh, Euy Young4
1 Department of Surgery, Ajou University Medical Center, Suwon-si, Republic of Korea
2 Department of Surgery, Ajou University Medical Center, Suwon-si, Republic of Korea
3 Department of Surgery, Ajou University Medical Center, Suwon-si, Republic of Korea
4 Department of Surgery, Ajou University Medical Center, Suwon-si, Republic of Korea
Background: Follicular variant papillary thyroid carcinoma (FVPTC) is known to have a good prognosis, but distant metastases were reported in some reports. The aim of this study is to find the clinicopathologic variables associated with aggression of FVPTC.
Methods: We retrospectively reviewed medical records of all patients with FVPTC between January 2006 and April 2016 in Ajou University Medical Center. A total of 488 patients underwent thyroidectomy. By exclusion of patients who diagnosed with other thyroid carcinoma and received primary surgery at other hospitals, 364 patients enrolled.
Results: 364 patients included 56 males (15.4%) and 308 females (84.6%), with the mean age of 47.7±11.4 years (range, 14-82 years). The mean follow-up period was 44.4 months (range, 0.3-123.9 months). The mean tumor size was 11.9±10.8mm (range, 1-80mm). 355 patients (97.5%) underwent central or lateral lymph node dissection while thyroidectomy, 74 out of the 355 patients (20.8%) had lymph node metastasis (LNM). Tumor size, lymphovascular permeation, and extrathyroidal extension were significantly correlated with LNM (p=0.01, p<0.001, and p<0.001, respectively). 4 patients (1.1%) had distant metastasis during follow-up period. In 3 patients, distant metastasis was found on whole body scan and eliminated by radioactive iodine (RAI) ablation. Tumor size was significantly correlated with distant metastasis (p=0.043).
Conclusions: FVPTC is known to have a good prognosis, but aggressive instances definitely exist. Especially in the case of infiltrative FVPTC, there is a need for more attention. Whole body scan and postoperative stimulated thyroglobulin before RAI ablation may be helpful to discern distant metastasis.
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