Clinicopathological features for predicting central and lateral lymph node metastasis in papillary thyroid microcarcinoma: Analysis of 66 cases that underwent central and lateral lymph node dissection

Abstract

Currently the surgical approach for papillary thyroid microcarcinoma (PTMC), particularly the range of lymph node dissection, remains controversial. The present study aims to evaluate the risk factors for central and lateral lymph node metastasis (CLNM and LLNM) for appropriate clinical decision of neck lymph node dissection in PTMC. A total of 66 cases of PTMC that underwent unilateral or bilateral lobectomy plus prophylactic cervical lymph node dissection were collected for clinicopathological evaluation, including age, gender, tumor size, subtypes, extrathyroidal invasion, multifocality, calcifications, loss of cellular polarity/cohesiveness (LOP/C) in the invasive front, CLNM and LLNM, and retrospectively analysis. Univariate analysis revealed that LOP/C was significantly associated with CLNM (P=0.001) and LLNM (P<0.0001). The male gender was a risk factor of CLNM (P=0.04), while the age <45 years, tumor size >0.5 cm and multifocality were high-risk factors of LLNM (P=0.022, 0.044 and 0.005, respectively). Multivariable analysis revealed that LOP/C was significantly associated with CLNM [P=0.007, odds ratio (OR)=7.765, 95% confidence interval (CI)=1.773–33.996] and LLNM [P=0.029, OR=5.717, 95% CI=1.190–27.470]. Both multivariable analysis and χ2 test revealed that CLNM was another important high-risk factor of LLNM (P=0.021, OR=5.444, 95% CI=1.290–22.969, χ2=17.867, P<0.001). The present study revealed that prophylactic central lymph node dissection is essential for PTMC surgery and that prophylactic lateral lymph node dissection is recommend for patients with LOP/C and CLNM, which can be performed by intraoperative frozen section pathological examination. This must be considered discreetly in the case of patients with age <45 years, tumor size >0.5 cm and multifocal lesions.

Clinical analysis of cervical lymph node metastasis risk factors in patients with papillary thyroid microcarcinoma

“…Additionally, we found that the multifocal lesion in PTMC was an important risk factor in CLNM. This finding is consistent with the data reported [7, 20, 21, 26–29]. Furthermore, with the increase of the sum of the maximum diameter of multifocal in a unilateral lobe, not only was the probability of CLNM increased, but also the probability of LLNM (Table 4).…”

“…Jeon et al [24] showed that age ≥ 45 years was at a higher risk of LNM while male was not an independent risk factor. On the contrary, some studies revealed that both male and younger age were risk factors [21, 22, 25, 26]. In our study, male was an independent risk factor for LNM and CLNM, rather than for LLNM.…”

Model of lymph node metastasis posterior to the right recurrent laryngeal nerve in papillary thyroid carcinoma

“…Similar findings of male sex and younger age as risk factors for LN-prRLN metastasis were also reported in the literature. 17 , 18 Another study suggested that adolescents are more likely to develop neck LNM. 19 …”

Routine Lateral Level V Dissection May Not Be Necessary for Papillary Thyroid Microcarcinoma With Lateral Lymph Node Metastasis: A Retrospective Study of 252 Cases

“…Although lateral neck compartment involvement is less common in PTMC patients, whether the LLNM pattern of PTMC is the same as that of PTC with >1 cm tumors is still debatable (12–14). Moreover, PTMC patients with LLNM exhibit more frequent multifocality and skip metastasis and less central lymph node metastasis (CLNM) than do PTC patients with tumors larger than 1 cm (14, 15). Whether level V lymph nodes should be routinely dissected in PTMC patients with LLNM remains unknown because of the lack of evidence.…”