Clinicopathologic Characteristics of Papillary Carcinoma in the Thyroid Isthmus

ABSTRACT

PURPOSE: Surgical approaches for papillary thyroid carcinoma remain controversial. Moreover, previous reports regarding surgical strategy for papillary carcinoma of thyroid isthmus are very few. The aims of this study are to analyze the clinicopathologic features of papillary thyroid carcinoma of the isthmus and to develop more appropriate surgical strategies. METHODS: Prospectively, papillary carcinoma arising thyroid isthmus (n=35) was included in this study from June 2006 to December 2008. All of the patients had total thyroidectomy with bilateral central compartment node dissection performed. Lateral nodes were sampled for frozen biopsy when metastasis was suspected by preoperative study. Thirty-five patients, who had unilateral papillary thyroid carcinoma, had total thyroidectomy with bilateral central compartment node dissection as control group and compared with papillary thyroid carcinoma of isthmus. RESULTS: Lymph node metastasis was higher than control group in patients of isthmus cancer (51% vs 20%, P<0.05). Capsular invasion and multifocality observed in 63% and 23% respectively, but there was no significant difference compared to control group, statistically. Capsular invasion showed a positive correlation with lymph node metastasis by univariate and multivariate analysis. Analysis of ipsilateral nodal metastatic distribution revealed no definite metastatic pattern. Tracheal adhesion was observed in 4 cases of isthmus cancer group. CONCLUSION: In conclusion, it is recommended that bilateral CCND is needed as an appropriate primary surgical procedure for localized papillary carcinoma of thyroid isthmus.