Completion Thyroidectomy in Patient with Differentiated Thyroid Cancer Who Initially Underwent Ipsilateral Operation / 대한내분비학회지

ABSTRACT

BACKGROUND: In some instances, thyroid cancer may be diagnosed only after resection of a putative or suspected benign nodule. In these cases a complete thyroidectomy is usually recommended to prevent recurrence. We analyzed the frequency of malignancy in the contralateral lobe after a complete thyroidectomy, and assessed the factors that may predict the presence of a malignancy, which might necessitate a complete thyroidectomy. METHODS: Between 1995 and 2001, 65 patients, who initially underwent a lobectomy and isthmectomy, but were finally diagnosed with differentiated thyroid carcinoma, underwent complete thyroidectomies. Their mean age was 39.8 +/- 12.4 years, ranging, 14 to 71 years. After initial surgery, 45 proved to have follicular carcinomas, 18 papillary carcinomas, 1 medullary and 1 insular carcinoma. The mean tumor size was 4.0 +/- 1.8 cm, ranging from 0.3 to 8.5 cm. After a complete thyroidectomy, the presence of a tumor the at contralateral lobe was assessed according to clinical parameters and the pathological findings in the ipsilateral lobe. RESULTS: The first surgeries revealed tumor multifocality in 27 cases, perithyroidal tumor extension in 4 and lymph node metastasis in 1. On completion of the thyroidectomy, 22 of the 65 patients had a malignancy in the contralateral lobe. Age, sex, size or the pathological primary tumor type, were not associated with the presence of additional tumors at the contralateral lobe. Tumor multifocality at the first surgery was the only significant variable to predict the presence of a tumor in the contralateral lobe. CONCLUSION: When thyroid cancer is diagnosed after ipsilateral surgery, the only predictive factor for the presence of a contralateral tumor was multifocality. We believe that a complete thyroidectomy is mandatory in these cases.