Total versus hemithyroidectomy for microscopic papillary thyroid cancer

Background: No increased mortality has been reported in patients with thyroid papillary microcarcinoma (PMC); however, neck recurrences and distant metastases have been described. In this study, we compare patients’ outcomes after total thyroidectomy vs hemithyroidectomy for treatment of thyroid PMC. Methods: Two hundred and ninety-three patients from two major medical centers in Israel were included. The mean follow-up period was 7.2±6.8 yr. Results: Total thyroidectomy was performed in 214 patients and hemithyroidectomy in 79 patients. Mean tumor size was 6.3±3 mm. Lymph-node (LN) metastases and extraglandular extension were more frequent in the total thyroidectomy group than in the hemithyroidectomy group, 24.8% vs 1.3% (p<0.001) and 11.7% vs 3.8% (p=0.042), respectively. The cumulative incidence of recurrence at the end of follow-up was 13.2% in the total thyroidectomy group and 14.3% in the hemithyroidectomy group (p=ns). The incidence of recurrence was higher in patients with LN involvement in both groups. Considering low risk patients only (monofocal tumors, no LN involvement, no extraglandular extension; no.=63 in the total thyroidectomy group vs no.=60 in the hemithyroidectomy group) neck recurrence was found in 10% of patients in the hemithyroidectomy group but none in the total thyroidectomy group. In the hemithyroidectomy group, all locoregional recurrences were diagnosed using ultrasonography, compared to 47.6% in the total thyroidectomy group. Conclusion: For patients with monofocal disease within the thyroid gland and no LN involvement, hemithyroidectomy can be considered an option, bearing in mind a higher risk for recurrence. For all other patients with PMC, we propose total thyroidectomy as initial treatment.