Disease control of differentiated thyroid carcinomas by hemithyroidectomy.

INTRODUCTION Most differentiated thyroid carcinomas (DTC) are treated by total thyroidectomy in Hong Kong. This study investigates the outcome of tumour control in selected patients treated by hemithyroidectomy, which is beneficial in terms of having a lower operative morbidity. METHODS This is a retrospective study of prospectively collected data from our cancer registry. Patients with pathologically proven differentiated thyroid carcinoma were stratified into risk groups according to the patients' age, tumour size, extrathyroid spread and distant metastasis. Low-risk patients were managed with hemithyroidectomy without postoperative radioactive iodine. Central compartment lymph node dissection was also carried out if the diagnosis was confirmed preoperatively. The oncological outcome and surgical morbidity were evaluated. RESULTS A total of 236 patients with the diagnosis of DTC underwent a thyroidectomy at our institution during a 24-year period. 93 patients were initially treated by hemithyroidectomy. Subsequent evaluation was focused on this subgroup. The mean follow-up period was 63.3 +/- 55.1 months. The mean tumour diameter was 22.1 +/- 20.8 mm. The histopathologic diagnoses were papillary carcinoma (69 cases; 74.2 percent), follicular carcinoma (20 cases; 21.5 percent) and Hurthle cell carcinoma (four cases; 4.3 percent). 23 (24.7 percent) patients underwent hemithyroidectomy coupled with central compartment dissection. Pathologically proven lymph node metastasis was diagnosed in 12 (12.9 percent) patients. Transient vocal cord palsy occurred in six (6.5 percent) patients, while permanent vocal cord palsy occurred in two (2.2 percent). Local tumour recurrence arose in only one (1.1 percent) patient. No patient succumbed to the thyroid cancer. CONCLUSION Hemithyroidectomy coupled with central compartment dissection in selected cases of DTC can achieve excellent tumour control with minimal surgical morbidity.