Yu, Hye-Mi;Ha, Tae-Kwun;Ryu, Sung-Mock;Kim, Woon-Won;Kim, Sang-Hyo
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Background : Though papillary microcarcinoma(PMC) of thyroid gland is known to have very favorable long-term prognosis, the recurrence in the neck and distant metastasis have been often reported. The predictive factors of node metastasis and tumor recurrence in clinical course were investigated to define surgical decision or guidelines in surgery of papillary microcarcinoma. Methods : The authors conducted a retrospective analysis of 216 patients of PMC treated with surgery at Department of Surgery, Busan Paik Hospital for the period from 1997 to 2007. Of these patients, 58 cases showing cervical lymph node metastasis at initial surgery were studied. Results : In overall 216 patients, the sex ratio of male to female was 1 : 9.3(male 21, female 195 cases), the mean age at the time of diagnosis was 44.7 years and the median tumor size was 6.61mm. Neck lymph node metastasis was found in 58 patients(26.9%), thyroid capsular invasion was 56 cases(25.9%), multifocality and bilaterality were found in 32(14.8%) and 29 cases(13.4%), respectively. Through statistical analysis, sex, capsular invasion, ETE, and tumor size(>5mm) were considered to be predictive factors of cervical lymph nodes metastasis. Of them, capsular invasion was the most predictive indicator of cervical lymph node metastasis on multivariate analysis. Nodal recurrence was observed in 6 of 58 patients of node positive at initial surgery. Conclusion : The cervical lymph node metastasis is known to be a risk factor of prognosis in PMC of thyroid gland. The results of this study showed four statistically significant independent predictive factors of cervical lymph node metastasis in PMC : capsular invasion, tumor size(>5mm), ETE, and sex. On multivariate analysis, capsular invasion was a great influencing factor in prediction of lymph node metastasis. Basically, patients who has predictive factors of cervical lymph node metastasis should have a thorough investigation, and close surveillance for nodal status is required in follow-up.