Korean J Endocr Surg.  2008 Dec;8(4):243-249. 10.16956/kjes.2008.8.4.243.

The Clinical Significance of Minimal Extrathyroid Extension in Patients with Papillary Thyroid Microcarcinoma

• Lee JB
• Kim HY
• Woo SW
• Ryu WS
• Lee JA
• Son GS
• Bae JW
• Lee YM

• KMID: 2375841
• DOI: http://doi.org/10.16956/kjes.2008.8.4.243

Abstract

PURPOSE
The prognosis of papillary thyroid carcinoma is determined by such risk factors as old age, male gender, a large tumor size and extrathyroid extension. The aim of this study was to investigate the value of extrathyroid extension for the recurrence of papillary microcarcinoma and its association with the risk factors for papillary thyroid carcinoma.
METHODS
We retrospectively studied 167 patients with papillary microcarcinoma and who underwent thyroidectomy from Feb. 2003 to Dec. 2008. Papillary microcarcinoma (PTMC) was defined as a tumor smaller than 1 cm and an extrathyroid extension was identified by the pathological findings. Age, gender, extrathyroid extensions, the operative methods, lymph node metastasis and the MACIS score were analyzed by the appropriate statistical methods.
RESULTS
Patients with PTMC showed a lower MACIS score, fewer lymph node metastasis and less extrathyroid extension, as compared to the patients with papillary thyroid carcinoma. Total thyroidectomy and selective lymph node dissection were less frequently done in the patients suffering with PTMC. Analysis of the risk factors showed that PTMC had a close relationship with lymph node metastasis, the extent of surgery and multifocal cancer. The disease free survival rate of the patients with PTMC was statistically related with lymph node metastasis, but not with an extrathyroid extension (P=0.001).
CONCLUSION
The patients with PTMC showed less lymph node metastasis and extrathyroid extension as compared to the patients with PTC. Lymph node metastasis of PTMC is an independent factor for disease free survival, but minimal extrathyroid extension is not related with recurrence. PTMC with lymph node metastasis should be regarded as an aggressive large tumor and lymph node dissection should be done.

Keyword

Papillary thyroid microcarcinoma; Minimal extrathyroid extension; Lymph node metastasis

MeSH Terms

Disease-Free Survival
Humans
Lymph Node Excision
Lymph Nodes
Male
Neoplasm Metastasis
Prognosis
Recurrence
Retrospective Studies
Risk Factors
Thyroid Gland*
Thyroid Neoplasms
Thyroidectomy