Papillary thyroid microcarcinoma. Frequency and risk factors of lymph node metastases

Abstract

Background: surgical management of lymph nodes in papillary thyroid microcarcinoma is controversial due to its excellent overall prognosis.
Objetive: to quantify the frequency and pattern of lymph node metastasis in patients operated on for papillary thyroid microcarcinoma and to identify predictive factors of regional disease.
Setting: private practice.
Design: retrospective, observational.
Population: between June 2002 and June 2012, 434 patients with papillary thyroid microcarcinoma underwent total thyroidectomy and therapeutic neck dissection only when there was biopsy proved lymph node metastasis.
Method: review of clinical records and pathological reports.
Results: 66 patients (15.2 %) had histologically positive lymph nodes. Metastasis in jugular lymph nodes with normal central nodes (skip metastasis) was found in 12 (2.76 %) cases. Multivariate analysis showed that less than 45 years (p = 0.02), extracapsular invasion (p = 0.003) and palpable adenopathy (p = 0.001), were independent risk factors of lymph node metastasis. These factors, together, had high specificity (99.7 %) but low sensibility (19.7 %).
Conclusions: surgical strategy employed allowed to diagnostic lymph node metastases in both central and lateral compartments; this is of particular importance because even though some of the factors studied proved to be predictive of lack of lymph node metastases, additional variables are needed to predict presence of regional disease in this subset of thyroid cancer patients.