Contralateral papillary thyroid cancer: does size matter?

Background: The optimal extent of thyroidectomy for papillary thyroid cancer (PTC) <1 cm is controversial. Our aim was to identify the rate and factors predictive of contralateral PTC in these patients.

Methods: We examined 228 patients with PTC who underwent either completion or total thyroidectomy and analyzed the predictive value of tumor size, histology, margin status, capsular invasion, extrathyroid extension, multifocality, and node metastases.

Results: We observed no differences in the rate of contralateral disease in patients with primary PTC > or =1 cm compared with those having disease <1 cm, 30% versus 24%, respectively (P = .43). Multifocality was the only factor predictive of contralateral PTC in patients with tumors <1 cm (P = .02). Patients with tumors <.5 cm also had a comparable rate of contralateral disease (27%).

Conclusions: The presence of contralateral PTC appears to be unrelated to the size of the primary tumor. Furthermore, in patients with PTC <1 cm, multifocality is a risk factor for PTC in the contralateral lobe.