Korean J Otorhinolaryngol-Head Neck Surg.  2014 Mar;57(3):166-171. 10.3342/kjorl-hns.2014.57.3.166.

Clinical Impact of Occult Multifocal Disease Identified after Hemithyroidectomy in Patients with Papillary Thyroid Microcarcinoma

• Ahn D
• Sohn JH
• Kim H
• Jeong JY
• Jung H

• KMID: 2277887
• DOI: http://doi.org/10.3342/kjorl-hns.2014.57.3.166

Abstract

BACKGROUND AND OBJECTIVES
Occult multifocal diseases are often identified after hemithyroidectomy in patients with papillary thyroid microcarcinoma (PTMC). There has been considerable debate with regard to whether multifocal diseases actually behave more aggressively compared with unifocal diseases, particularly PTMC. The present study aimed at evaluating the clinical impact of occult multifocal diseases on the recurrence of PTMC treated with hemithyroidectomy.
SUBJECTS AND METHOD
We compared the clinicopathological characteristics and 5-year outcomes for 319 patients with unifocal PTMC patients and 29 patients with occult multifocal PTMC, all of whom were treated with hemithyroidectomy between January 2004 and December 2010.
RESULTS
The incidence of occult multifocal disease was 8.4%, with a mean size of 0.28 cm. Although microscopic extrathyroidal extension (ETE) was more frequent in patients with occult multifocal PTMC as compared with that of unifocal diseases (41.4% vs. 23.2%, p=0.030), multifocality was not associated with age, primary tumor size, and concurrent Hashimoto's thyroiditis. With respect to recurrence, there was no difference between the unifocal and multifocal groups during the mean 55.8-month follow-up period (4.4% vs. 10.3%, p=0.160). In addition, univariate and multivariate analyses revealed no meaningful association between recurrence and presence of occult multifocal diseases in patients with PTMC treated with hemithyroidectomy.
CONCLUSION
Although presence of occult multifocal diseases was associated with microscopic ETE, its clinical impact on disease recurrence was not significant in PTMC patients treated with hemithyroidectomy. Therefore, multifocality identified after hemithyroidectomy would not be an absolute indication for the completion of thyroidectomy in patients with PTMC.

Keyword

Papillary thyroid microcarcinoma; Recurrence; Thyroidectomy

MeSH Terms

Follow-Up Studies
Humans
Incidence
Multivariate Analysis
Recurrence
Thyroid Gland*
Thyroidectomy
Thyroiditis