Long-Term Prognosis of Unilateral and Multifocal Papillary Thyroid Microcarcinoma After Unilateral Lobectomy Versus Total Thyroidectomy.

Background: Multifocal papillary thyroid microcarcinoma (PTMC) has been associated with poor outcomes; however, we often encounter pathologically confirmed unilateral multifocal PTMC after surgery. To date, no consensus on the proper surgical extent for patients with this form of PTMC has been reported.

Objective: The aim of this study was to analyze the effect of the type of surgical treatment on disease recurrence in patients with unilateral multifocal PTMC.

Methods: We retrospectively analyzed data from 255 patients with unilateral, multifocal, node-negative PTMC between March 1999 and December 2012. We evaluated two groups of patients: those who underwent unilateral lobectomy (Group I, n = 127) and those who underwent total thyroidectomy (Group II, n = 128). During the follow-up period, which lasted a median of 94.8 months, we assessed locoregional recurrence (LRR).

Results: There was no statistically significant difference between the two groups with regard to LRR at follow-up (3.15% for Group I vs. 0.78% for Group II; p = 0.244). The association between the type of surgical treatment and LRR remained nonsignificant after adjusting for potential confounders such as age, tumor size, microscopic extrathyroidal extension, and lymphovascular invasion (p = 0.115). During follow-up, the incidence of transient hypocalcemia (0% vs. 8.6%; p = 0.001) and vocal fold paralysis (1.6% vs. 9.4%; p = 0.011) was higher in Group II than in Group I.

Conclusions: Even though randomized controlled trials are the only option to obtain a definitive answer to this question, unilateral lobectomy may be a safe operative option for selected patients with unilateral, multifocal, node-negative PTMC.