The objective of the study was to assess the patterns of central cervical lymph node metastasis (CLNM) and evaluate the prophylactic central lymph node dissection (CLND) in papillary thyroid carcinoma (PTC) patients without clinical positive lymph nodes. We retrospectively reviewed 1555 patients with PTC between 2003 and 2008. Lymph node metastatic risk factors and the pattern of lymph node metastasis in PTC were studied using multivariate analysis. Male patients, aged ≤ 45 years, the presence of extrathyroidal extension, and a primary tumor size > 10 mm were identified as risk factors for CLNM with odds ratios of 2.089, 2.417, 1.534, and 3.079, respectively. Among 1555 patients, 97 cases (6.24%) had transient hypoparathyroidism, and only two patients (0.13%) had permanent hypoparathyroidism. Recurrent laryngeal nerve injury after thyroidectomy occurred in 14 patients (0.9%). In this group, nine cases were transient injury and the remaining five were permanent. During the period of follow-up, ranging from 5 years to 10 years, 18 patients (1.16%) were found with locoregional recurrence. Taken together, in terms of the high incidence rate of CLNM in cN0 PTC patients, we believe that routine prophylactic CLND is optimal for clinically negative PTC patients, during their first treatment, especially for those with risk factors for CLNM.

Active surveillance (AS) can be considered as an alternative to immediate surgery in low-risk papillary thyroid microcarcinoma (PTMC) without clinically apparent lymph nodes, gross extrathyroidal extension (ETE), and/or distant metastasis according to American Thyroid Association. However, in the past AS has been controversial, as evidence supporting AS in the management of PTMC was scarce. The most prominent of these controversies included, the limited accuracy and utility of ultrasound (US) in the detection of ETE, malignant lymph node involvement or the advent of novel lymph node malignancy during AS, and disease progression. We summarized publications and indicated: (1) US, performer-dependent, could not accurately diagnose gross ETE or malignant lymph node involvement in PTMC. However, the combination of computed tomography and US provided more accurate diagnostic performance, especially in terms of selection sensitivity. (2) Compared to immediate surgery patients, low-risk PTMC patients had a slightly higher rate of lymph node metastases (LNM), although the overall rate for both groups remained low. (3) Recent advances in the sensitivity and specificity of imaging and incorporation of diagnostic biomarkers have significantly improved confidence in the ability to differentiate indolent vs. aggressive PTMCs. Our paper reviewed current imagings and biomarkers with initial promise to help select AS candidates more safely and effectively. These challenges and prospects are important areas for future research to promote AS in PTMC.

Whether we should use carbon nanoparticle (CN) routinely in thyroid surgery is still controversial. 406 papillary thyroid cancer (PTC) patients who underwent total thyroidectomy (TT) with bilateral central lymph node dissection (CLND) from January 2010 to December 2012 were retrospectively analyzed. The incidence of transient hypoparathyroidism and hypocalcemia in CN group was significantly lower than the control group at second, fifth day after surgery (P = 0.004, 0.042, 0.002 and 0.045 respectively). However, no significant difference existed between the two groups about the permanent hypoparathyroidism and hypocalcemia (P = 1.000). Total number of central lymph nodes and metastatic lymph nodes in CN group were more than those in control group (P = 0.031 and 0.038 respectively). However, recurrence was not significantly different between the two groups after at least 5-year follow up (P = 0.7917). In the subgroup of prophylactic and therapeutic CLND study, no significant difference existed between the two groups (P = 0.5295 and 0.8459 respectively). CN significantly help in identifying the parathyroid glands in surgery and increased the number of lymph nodes in central compartment. However, we should not exaggerate the function of CN since it couldn’t improve the permanent hypoparathyroidism and recurrence in PTC patients who underwent TT with bilateral CLND.

The extent of surgery in patients with unilateral multifocal papillary thyroid microcarcinoma (UMPTMC) remains to be controversial. Aimed to improve surgical management of UMPTMC, this study was performed to identify the recurrence of UMPTMC and analyze its predictive factors. This study was approved by the Ethical Committee of The First Hospital of the Jilin University, and written informed consent was given by participants for their clinical records to be used in this study. We retrospectively analyzed a total of 97 consecutive patients who underwent initial surgery for the treatment of UMPTMC at The First Hospital of Jilin University, between October 2005 and October 2006. Altogether, 97 patients of UMPTMC have been enrolled in our study, in which 57 cases were performed with hemithyroidectomy (HT) while other 40 cases with total thyroidectomy (TT). The sum diameter of all tumors >1 cm was more frequent in HT group than in TT group (40.35 vs 20%; p = 0.046). Positive central lymph nodes were found more frequently in the TT patients than in the HT patients (80 vs 59.65%; p = 0.046). Tumor recurrence was seen more frequently in the HT cases than in the TT cases (26 vs 5%; p = 0.007). The disease-free survival period was significantly shorter for the HT patients than for the TT patients (p = 0.0059 by the log-rank test). The disease-free survival rates at 5 and 10 years were 91.23 and 73.68%, respectively, in the HT group and 100 and 92.5%, respectively, in the TT group. Univariate analysis by Cox’s proportional hazards method showed male gender, sum diameter of all tumors >1 cm, and central lymph node metastases (CLNM) to be risk factors for recurrence of HT patients. Male gender and sum diameter >1 cm were factors identified for multivariate analysis by Cox’s proportional hazards method which yielded risk ratios of 3.037 [CI 1.026–8.988; p = 0.045] and 5.475 [CI 1.389–21.572; p = 0.015] in the HT group. In summary, with an increased risk of recurrence, TT may be more reasonable as initial surgery in UMPTMC, especially with male gender and total tumor diameter greater than 1 cm.

Background: Clinical and ultrasonic risk factors for lateral lymph node metastasis (LLNM) in papillary thyroid microcarcinoma (PTMC) are not well-defined. Herein, a systematic review and meta-analysis was conducted to investigate clinicopathologic and ultrasonic risk features for LLNM in PTMC. Methods: A systematic search of electronic databases (PubMed, Embase, Cochrane Library, and Web of Science) for studies published until April 2019 was performed. Case–control studies and randomized controlled trials that studied clinical and ultrasonic risk factors of LLNM in PTMC were included. Results: Fourteen studies (all retrospective studies) involving 43,750 patients met final inclusion criteria. From the pooled analyses, younger age<45 (OR, 1.55; 95% CI, 1.16–2.07; P = 0.003), male patients (OR, 1.94; 95% CI, 1.55–2.42; P < 0.00), extrathyroidal extension (OR, 3.63; 95% CI, 2.28–5.77; P <0.00), tumor multifocality (OR, 2.24; 95% CI, 1.53–3.28; P 0.5 cm (OR, 2.24; 95% CI, 1.53–3.28; P < 0.00), central lymph node metastasis (OR, 5.61; 95% CI, 4.64–6.79; P < 0.00), >25% tumor contact with thyroid capsule (OR, 6.66; 95% CI, 1.96–22.65; P = 0.002), tumor calcification (OR, 2.90; 95% CI, 1.71–4.93; P < 0.00), upper tumor (OR, 3.18; 95% CI, 2.23–4.55; P < 0.00) were significantly associated with increased risk of LLNM in PTMC, while Hashimoto's thyroiditis and other ultrasonic features (solid tumor, hypoechoic tumor, smooth margin, and taller than wide tumor) were not significantly associated with LLNM in PTMC. Conclusions: Our analysis identified several clinicopathologic and ultrasonic factors associated with LLNM in PTMC. This finding highlights the need for a cautious and frequent postoperative surveillance of the lateral neck in high-risk PTMC patients. Moreover, high-risk ultrasonic features also need to be considered during selection of PTMC for active surveillance.

Solitary papillary thyroid microcarcinoma (PTMC) without gross extrathyroidal extension (ETE) were the main candidates for active surveillance (AS). Predictive factors of lateral lymph node metastasis (LLNM) in solitary PTMC without gross ETE were essential but still unknown. Altogether, 171 patients of solitary PTMC without gross ETE were enrolled in our study and divided into two groups. Group A: 123 patients without lateral lymph node dissection (LLND) were considered to be LLNM negative because there was no lateral recurrence by at least 8-year follow up for all patients. Group B: 48 patients with LLND were considered to be LLNM positive which confirmed by postoperative pathology. Multivariate logistic regression showed male gender, upper location of tumor and diameter of tumor ≥7 mm to be predictive factors (odds ratio = 4.237 [confidence interval (CI) 1.365-13.149, p = 0.012; odds ratio = 2.933 [CI 1.117-7.700, p = 0.029; odds ratio = 4.557 [CI 1383-15.016, p = 0.013) for LLNM in solitary PTMC patients without gross ETE. Multiple level metastasis happened in 29 (60.42%) cases while single level metastasis in 19 (39.58%). Within the lateral cervical lymph node chain, level Ⅲ nodes were consistently the most frequently involved (38/48, 79%), following by level Ⅳ (27/48, 56%), level Ⅱ (25/48, 52%) and level V (5/48, 10%). Most interesting, there are 12 (12/48, 25%) skip metastatic (positive in lateral neck and negative in central neck) patients among LLNM positive group. Male gender, upper location of tumor and diameter of tumor ≥0.7 cm to be predictive factors of LLNM in solitary PTMC without gross ETE.