Hemithyroidectomy increases the risk of disease recurrence in patients with ipsilateral multifocal papillary thyroid carcinoma.

Papillary thyroid carcinoma (PTC) is often clinically multifocal. In this study, the clinicopathological characteristics of a total of 347 PTC patients treated between 2006 and 2007 were investigated in order to assess the risk factors for tumor recurrence in patients with multifocal PTC. Of all the PTC cases reviewed, 35 (10%) were categorized as multifocal PTC. Patients with multifocal PTC were significantly more likely to have extrathyroidal extension, lymph node metastases and disease recurrence (P<0.05). Hemithyroidectomy resulted in a significantly higher incidence of tumor recurrence in patients with ipsilateral multifocal PTC compared with unifocal PTC patients (P<0.01). In conclusion, hemithyroidectomy was associated with tumor recurrence in patients with ipsilateral multifocal PTC but not those with unifocal PTC. Hemithyroidectomy should only be carried out after careful deliberation when involving patients with ipsilateral multifocal PTC.