Features Of Papillary Thyroid Microcarcinoma Research Articles

Comprehensive Long-Read Sequencing Analysis Discloses the Transcriptome Features of Papillary Thyroid Microcarcinoma.

Papillary thyroid microcarcinoma (PTMC) is the most common type of thyroid cancer. It has been shown that lymph node metastasis is associated with poor prognosis in patients with PTMC. We aim to characterize the PTMC transcriptome landscape and identify the candidate transcripts that are associated with lateral neck lymph node metastasis of PTMC. We performed full-length transcriptome sequencing in 64 PTMC samples. Standard bioinformatic pipelines were applied to characterize and annotate the full-length expression profiles of 2 PTMC subtypes. Functional open reading frame (ORF) annotation of the known and novel transcripts were predicted by HMMER, DeepLoc, and DeepTMHMM tools. Candidate transcripts associated with the pN1b subtype were identified after transcript quantification and differential gene expression analyses. We found that skipping exons accounted for the more than 27.82% of the alternative splicing events. At least 42.56% of the discovered transcripts were novel isoforms of annotated genes. A total of 39 193 ORFs in novel transcripts and 18 596 ORFs in known transcripts were identified. Distribution patterns of the characterized transcripts in functional domain, subcellular localization, and transmembrane structure were predicted. In total, 1033 and 1204 differentially expressed genes were identified in the pN0 and pN1b groups, respectively. Moreover, novel isoforms of FRMD3, NOD1, and SHROOM4 were highlighted for their association with pN1b subtype. Our data provided the global transcriptome landscape of PTMC and also revealed the novel isoforms that associated with PTMC aggressiveness.

Prognostication of papillary thyroid microcarcinoma based on preoperative ultrasound.

Diagnosis of papillary thyroid microcarcinoma, defined as papillary thyroid carcinoma measuring 1cm or less in greatest diameter, has increased with improvements in ultrasound technology and widespread familiarity and utilization. Given the indolent course of papillary thyroid carcinoma, active surveillance is considered an acceptable alternative to surgical resection for select patients. Candidacy for active surveillance is determined by a number of patient and tumor characteristics. Specifically, the location of the tumor within the thyroid gland plays one of the key roles in decision making. Here we evaluate characteristics of the primary tumor and distance to the thyroid capsule in association with locoregional metastases to help guide risk assessment. Retrospective chart review of all thyroid surgeries performed by two surgeons at one medical center from 2014-2021 to evaluate characteristics of papillary thyroid microcarcinoma on preoperative ultrasound that are associated with locoregional metastatic disease. Our data show a sensitivity of 65% and specificity of 95% for identifying regional metastases in papillary thyroid microcarcinoma using preoperative ultrasound. We found no correlation between regional metastasis and size of tumor, distance to thyroid capsule or trachea, tumor contour, or presence of autoimmune thyroiditis. Nodules in the superior or midpole were associated with central or lateral neck metastases, whereas nodules in the isthmus or inferior pole were only associated with central neck metastases. Active surveillance may be a reasonable option for even those papillary thyroid microcarcinomas adjacent to the thyroid capsule.

Risk factors for central lymph node metastasis in papillary thyroid microcarcinoma – a retrospective study of 1433 cases from a single center

The purpose of this retrospective study was to evaluate the clinicopathological features of papillary thyroid microcarcinoma (PTMC) and the lymph node metastasis of PTMC. We retrospectively reviewed atotal of 1433 patients with PTMC. The analysis data including demographics, tumor size, multifocality, bilateral, invasion capsule and Hashimoto's thyroiditis were collected from XinJiang, China. Univariate and multivariate analyses were performed to identify the clinicopathologic predictors of central lymph node metastasis: male gender [odds ratio (OR) = 2.358, p < 0.001], age ≤ 45 years (OR = 2.302, p 6.5 mm (OR = 2.388, p < 0.001), adjacent or invasion capsule (OR = 1.750, p = 0.002), Hashimoto's thyroiditis (OR = 0.501, p < 0.001). The optimal critical value of the number of dissected lymph nodes was found to be 8.5 using ROC analysis, with asensitivity and specificity of 41.8% and 75.5%, respectively. This study suggests that evaluation of nodal metastasis is required to guide the surgical treatment of PTMC patients.

EWSR1 rearrangement in papillary thyroid microcarcinoma is related to classic morphology and the presence of small-cell phenotype.

The Ewing sarcoma breakpoint region 1 (EWSR1) rearrangements with unknown genes were detected in a high percentage of classic variants of papillary thyroid carcinoma. The small-cell carcinoma of the thyroid with Ewing family tumor elements typically presents with EWSR1-FLI1 rearrangement suggesting the possible role of EWSR-FLI1 translocation in the loss of thyroid differentiation and acquisition of a small-cell phenotype. To determine the frequency and association of EWSR1 rearrangements, particularly the EWSR1-FLI1 fusion with clinicopathological features of papillary thyroid microcarcinoma (m-PTC) and the presence of small cells, we analyzed a series of 99 m-PTCs using the fluorescence in situ hybridization method. Ninety cases (90.9%) of m-PTC were positive for small cells. This group of m-PTC has shown more often invasive growth, lymphatics invasion, and moderate/extended intratumoral fibrosis. Three cases out of 99 were inconclusive for EWSR1 rearrangement. Eighty-nine (92.7%) and 27 (28.1%) out of 96 m-PTC cases were positive for EWSR1 rearrangement and EWSR1-FLI1 fusion, respectively. m-PTC with classical architectural pattern presented more frequently with EWSR1 rearrangement relative to m-PTC with other patterns (p = 0.005). Other clinicopathological features were not related to the presence of EWSR1 rearrangement or EWSR1-FLI1 fusion. The percentage of small cells present significantly correlated with the percentage of cells positive for EWSR1-FLI1 fusion (p = 0.05) and EWSR1 rearrangement (p < 0.001). EWSR1-FLI1 fusion is not rare in m-PTC and it is associated with the acquisition of small-cell phenotype. The EWSR1 gene rearrangement is a frequent event in m-PTC and is related to the classical pattern of m-PTC.

The relationship between lipotoxicity and risk of extrathyroidal extension in papillary thyroid microcarcinoma.

To explore the relationship between triglyceride (TG) levels and aggressive pathological characteristics in papillary thyroid microcarcinoma (PTMC) patients, especially the relationship between TG, BMI, age, and extrathyroidal extension (ETE). A retrospective analysis of 9663 patients with PTMC in a single center from 2010 to 2017 was included in this study. Binary logistic regression was used to analyze the relationship between serum TG and aggressive pathological characteristics of PTMC in different genders. Further analyzing the risk of high TG in different ages and BMI groups. Even after adjustment for confounding factors, high TG is still a risk factor for ETE in women with PTMC, but not a risk factor for men. Compared with the group with lower than 0.90 mmol/L, when the TG level is higher than 1.93 mmol/L, the risk of ETE in women increased by about 1.35-fold. The remaining two variables (BMI, age) as risk factors for ETE are analyzed. In the normal BMI group, high TG is still a risk factor for ETE. The risk of ETE in women more than 55 years old is significantly increased by 1.96-fold (1.34-fold in less than 55 years). High TG in women is positively correlated with the risk of ETE in PTMC. PTMC with high TG in elderly women (more than 55 years) has a higher risk of ETE. TG is a potential serological index for predicting the risk of ETE in women with normal BMI.

Clinical and ultrasonic features of papillary thyroid microcarcinoma and risk factors for central lymph node metastasis

Objective:To investigate the clinical and ultrasonic features of papillary thyroid microcarcinoma （PTMC） and the risk factors of central lymph node metastasis （CLNM）, to provide help for individualized treatment. Methods:One hundred and eighty-five patients with PTMC confirmed by surgery and pathology and underwent prophylactic CLN dissection were retrospectively analyzed. According to lymph node metastasis, patients were divided into metastasis group and non metastasis group. The size, shape, echo, aspect ratio, edge, protruding capsule, nodule location, calcification and calcification were analyzed. The relationship between clnm and ultrasonographic features, sex, age, single/multiple, whether or not with Hashimoto thyroiditis was analyzed. Results:Among 185 patients with PTMC, 55 cases had lymph node metastasis, and the metastasis rate was 30.0%. In univariate analysis, clnm of PTMC was significantly correlated with gender, age, tumor size, protruding capsule, type of calcification and single / multiple （all P<0.05）. In multivariate logistic regression analysis, tumor size, single/multiple, protruding capsule, gender and age were the risk factors of clnm. According to the ROC curve, when the age was 49.5 years old and the mass size was 4.8 mm, the diagnostic test yoden index reached the maximum value. Conclusion:When the risk factors of male, ≤49.5 years old, tumor size≥4.8 mm, multiple and protruding capsule appeared in PTMC patients, preventive CLN clearance should be taken actively.

Papillary Microcarcinoma: AN Epidemiological, Clinical, therapeutic and Prognostic Study of 35 Cases

Papillary microcarcinoma of the thyroid is defined as cancers having a diameter equal or inferior to 10 mm in the anatomopathological examination; The problematic of this pathology lies in its latent character, it is, thus, much more frequent than we thought or predicted. That is why, beyond specifying the epidemiological and clinical characteristics of papillary thyroid microcarcinoma, our ultimate goal was to determine the "gold standard" for the management of this entity.&#x0D; We carried out a descriptive retrospective study spread over 4 years including all cases of Papillary Microcarcinoma of the thyroid diagnosed within the department of ENT and Head and Neck Surgery of the medical center Mohammed VI in Marrakech; We collected 35 cases, and using their medical records we summarized their epidemiological, clinical and paraclinical data.&#x0D; None of our patients had a normal clinical examination, the palpation of our patients showed an isolated nodule in 20% of patients, the rest of our patients had clinically bilateral noticeable nodes. 80% of which were not clinically suspicious, and only three of our patients had palpable lymph nodes which was confirmed by the ultrasound, where the major suspicious character was their hypoechoic character ( 17 % were EU-TIRADS 5 ) With regard to surgical treatment, 28 of our patients (80%) underwent total thyroidectomy as a first step,4 patients underwent secondary totalization during the same operation after the extemporaneous examination came back positive for papillary microcarcinoma , 2 cases of remote loboisthmectomy after final histological examination showing papillary microcarcinoma , and one final case of totalization after extemporaneous examination of a superior right jugular lymph node with central necrosis. Neck dissection was performed in three cases. Postoperative outcomes were simple in all patients. Isotopic totalization by iodine 131 therapy was performed in four of our patients. Their indications were respectively: infiltrating tumor, extension to neighboring parenchyma, multifocality, lymph node metastasis. The survival rate of our series was 100%. The therapeutic protocol of papillary microcarcinoma is punctuated, to this day, with controversy, and faces a conservative attitude versus a radical one, it is the surgeon's duty to distinguish between the two attitudes.

Analysis of the factors for the lymph node metastasis in rⅥb region of thyroid micropapillary carcinoma and the application value of intraoperative nano-carbon

Objective:To investigate the relationship between lymph node metastasis in rⅥb region and pathological features of papillary thyroid microcarcinoma, and the application value of carbon nanoparticles in the operation for lymph node dissection in rⅥb region. Method:One hundred and seventy-five patients were divided into carbon nanoparticles group and the control group depending on whether carbon nanoparticles were used in the operation. The operation time, the number of central lymph node, the number of rⅥb region lymph node, hypocalcaemia symptom complex and hoarseness after the operaion were compared between the two groups. The lymph node metastasis in the rⅥb region and the pathological features of papillary thyroid microcarcinoma were statistically analyzed. Result:The amount of lymph nodes in Central District and rⅥb region was increased and the probability of parathyroid gland injury was decreased by using nano-carbon. The positive rate of lymph nodes in rⅥb region was not related to age, sex, aspect ratio of nodules and microcalcification, but was related to the tumor size, multifoci and the invasion of the capsule. The evaluation model of lymph node metastasis in rⅥb region was established based on the above three correlative features of color doppler ultrasound. The ROC curve analysis showed that the model had high application value . Conclusion:The tumor size, multiple foci and capsule invasion are risk factors for lymph node metastasis in rⅥb region of thyroid micropapillary carcinoma.

Association of BRAFV600E mutation with ultrasonographic features and clinicopathologic characteristics of papillary thyroid microcarcinoma: A retrospective study of 116 cases.

To analyze the association of BRAFV600E mutation with ultrasonographic (US) features and clinicopathologic characteristics in Chinese patients with papillary thyroid microcarcinoma (PTMC). We retrospectively reviewed 116 consecutive Chinese patients with PTMC diagnosed by postoperative pathology. The incidence of the BRAFV600E mutation was calculated. The US features and clinicopathologic characteristics were compared between BRAF-positive and BRAF-negative patients. The BRAFV600E mutation was detected in 60.3% of patients (70 of 116). Multifocality (OR: 3.681, P = 0.031), non-parallel orientation (OR: 3.181, P = 0.041) and lymph node metastasis (OR: 4.615, P = 0.009) were significantly associated with BRAFV600E mutation. Other US and clinicopathologic characteristics were not significantly related to the presence of BRAF mutation. Multifocality, non-parallel orientation and cervical lymph node metastasis are risk factors for BRAFV600E mutation in PTMC. These factors potentially guide treatment planning or prognosis evaluation.

Peripheral location and infiltrative margin predict invasive features of papillary thyroid microcarcinoma.

Tumor location in papillary thyroid microcarcinoma (PTMC) might determine tumor outgrowth from the thyroid gland. However, the clinical implications of tumor location and minimal extrathyroid extension (mETE) have not been well elucidated. We aimed to investigate the relationship between tumor location and mETE to predict the aggressiveness of PTMC. A total of 858 patients with PTMC were grouped according to tumor location on ultrasonography: central (cPTMC) and peripheral PTMC (pPTMC). PTMC without mETE (PTMC-mETE(-)) was divided further according to margin shape: encapsulated (E-) or infiltrative (I-). To understand the molecular biologic characteristics of PTMC presenting with an I-margin and mETE, transcriptome data from TCGA-THCA were analyzed using Gene Set Enrichment Analysis (GSEA). pPTMC (n = 807, 94.1%) accounted for the majority of cases; mETE was identified only in pPTMC (403/807; 49.9%). pPTMC-mETE(+) showed aggressive clinical characteristics that increased the odds ratio (OR) for lymph node metastasis (LNM). Interestingly, subgroup analysis of PTMC-mETE(-) revealed that the I-margin also increased the OR for LNM, independent of other clinical factors. GSEA of TCGA-THCA data suggested coordinated upregulation of genes related to epithelial-mesenchymal transition (EMT) in PTC with mETE. Immunohistochemical staining for laminin subunit gamma 2 (LAMC2), CD59, E-cadherin and vimentin showed that these markers of EMT were associated with progressive changes in E-margin PTMC-mETE(-), I-margin PTMC-mETE(-) and pPTMC-mETE(+). mETE related to peripheral location of PTMC is an important predictor of tumor invasiveness, as is the I-margin, which presents with EMT features similar to mETE. I-margin PTMC-mETE(-) and pPTMC-mETE(+) might reflect the pattern of invasive PTMC.

Clinicopathological features of papillary thyroid microcarcinoma with a diameter less than or equal to 5 mm.

This retrospective study was conducted to assess the epidemiological, clinical and histologic characteristics of incidentally identified and presurgically diagnosed papillary thyroid microcarcinomas less than or equal to 5 mm in size (small PTMC). Cases from October 2003 to February 2018 were retrieved from pathology databases, and their clinicopathological features were reviewed. There were a total of 182 cases of small PTMCs, 141 women and 41 men. The mean age at diagnosis was 53.5. Most of the small PTMCs were not detected on clinical examination and workup and were diagnosed incidentally during pathologic examination. 21.4% of small PTMCs showed multifocality, with 21 cases of unilateral multifocal lesions and 18 cases with bilateral multifocal tumors. Small PTMCs were most often follicular variant (51.9%) followed by classic type (47.5%). The average size of follicular variants appeared to be larger than that of the classic type PTMCs (2.84 ± 1.43 mm vs 2.26 ± 1.51 mm, P = 0.01). A total of 66 cases (36.3%) had regional lymph node sampling or selective neck dissection and 15 of these cases identified lymph node metastasis (22.7%). 46.7% of patients with node positive microcarcinomas were male compared with 16% male in group with negative lymph nodes (P = 0.03). Small PTMCs (≤5 mm) are often multifocal and bilateral and histology is commonly both the classical and follicular variant of PTC. While often diagnosed incidentally small PTMC can lead to regional lymph node involvement in a significant portion of cases and evaluation of the regional lymph nodes should be considered in the clinical management of these patients.

The Sonographic Findings of Papillary Thyroid Microcarcinomas

The purpose of this research was to compare the sonographic features of papillary thyroid microcarcinomas (micro-PTCs) to those of macro-PTCs. Patients with known PTC were retrospectively reviewed and divided into micro- or macro-PTC groups, according to the largest nodule diameter, ≤10 mm or &gt;10 mm, respectively. Eighty-nine nodules (62 macro-PTCs and 27 micro-PTCs) were evaluated. Contour irregularity was more common in micro-PTCs than macro-PTCs ( P &lt; .05). No significant difference was found in the presence of hypoechogenicity, heterogeneity, microcalcifications, cystic component, and absence of peripheral halo between groups ( P &gt; .05). Internal vascularity was detected in none of the micro-PTCs while being present in 13% of macro-PTCs ( P &lt; .05). Micro-PTCs demonstrated similar sonographic findings as larger PTCs. In micro-PTCs, the presence of irregular contours, in a micro-nodule, should increase suspicion and consideration for biopsy, when clinically indicated. Internal nodular vascularity may not be present in micro-PTCs and therefore not decrease the suspicion of malignancy in the presence of other suspicious sonographic features.

Association between BRAFV600E Mutations and Clinicopathological Features of Papillary Thyroid Microcarcinoma (PTMC)

Association between <i>BRAF^V600E</i> Mutations and Clinicopathological Features of Papillary Thyroid Microcarcinoma (PTMC)

Ultrasonographic features associated with false-negative and false-positive results of extrathyroidal extensions in papillary thyroid microcarcinoma.

To assess the ultrasonographic features affect accuracy of extrathyroid extension (ETE) evaluation on preoperative ultrasonography (US) in papillary thyroid microcarcinoma (PTMC). Of the total patients who underwent thyroid surgery, 516 patients with a tumor measuring less than 1cm on preoperative US were enrolled in this study. One blinded head and neck radiologist reviewed the preoperative US images to evaluate the US features of PTMC, and the pathologic reports were reviewed. The diagnostic accuracy rates, including sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), and accuracy, were calculated, and the factors associated with false-negative and false-positive results for ETE were analyzed. The sensitivity, specificity, PPV, NPV, and accuracy for predicting ETE according to sonographic criteria were 32.8%, 87.5%, 51.0%, 76.6%, and 71.7%, respectively. Non-adjacent to the trachea and unilateral lesion on US were significant factors associated with false-negative results. Size, shape, and location of PTMC on US are important factors that affect the US results in ETE evaluation.

The sonographic characteristics of papillary thyroid microcarcinoma and its risk evaluation of cervical lymphatic metastasis

Objective To investigate the sonographic characteristics of papillary thyroid microcarcinoma(PTMC) and the preoperative prediction value for cervical lymphatic metastasis of PTMC. Methods Three hundred and fifty-eight PTMC patients who were confirmed by pathology and accepted partly or totally thyroidectomy and neck dissection were collected to analyze the sonographic characteristics, all patients were classified according to multifocal carcinoma nodules and solitary carcinoma nodules; cervical lymphatic metastasis or not; the maximum diameter of carcinoma nodules. Univariate analysis and Logistic regression analysis were used. Results Compared with solitary PTMC, multifocal PTMC was prone to emerge blood flow signals, heterogeneity, cervical lymphatic metastasis(all P 1 cm, irregular edge, irregular shape, microcalcification, capsular invasion(all P<0.05). With Logistic regression analysis, the independent risk factors of cervical lymphatic metastasis in PTMC were multifocality and capsular invasion. Combining multifocality and capsular invasion, which area under the ROC(AUC) was 0.807. Conclusions Combining multifocality and capsular invasion significantly improves the risk of cervical lymphatic metastasis in PTMC by ultrasonography. Key words: Ultrasonography; Thyroid neoplasms; Lymphatic metastasis

Ultrasonography is valuable in evaluation of papillary thyroid microcarcinoma based on 5 mm tumor size.

Fine-needle aspiration was once done in suspected malignant thyroid nodules more than 5 mm in diameter. Five millimeter has been applied in many studies as the cut off tumor size in recent years. In this study, we would like to analyze the clinicopathological and ultrasonographic features of papillary thyroid microcarcinoma (PTMC) ≤5 mm and >5 mm with the aim of finding out the diagnostic value of ultrasonography. A total of 291 patients from January 2012 to October 2014 who underwent an ultrasound examination and were postoperatively diagnosed as PTMC were enrolled in the study. The patients were divided into Group A (≤5 mm) and Group B (>5 mm, ≤10 mm) based on diameter. The clinicopathological and ultrasonographic features of the two groups were statistically analyzed. In total, 291 thyroid tumors were analyzed in 291 patients. In patients who were identified with multiple tumors, the largest nodule in size was used for analysis. PTMC >5 mm in diameter were found with a higher incidence of lymph node metastasis and advanced tumor-node-metastasis (TNM) Stage (III/IV) with a significant difference, also with a larger part of multiple tumors compared to PTMC <5 mm. Of all the ultrasonographic features studied, calcification and peripheral halo were more significantly correlated with PTMC >5 mm. The presence of vascularity and blood supply were both associated with the tumor size. Larger tumor size of PTMC is more likely to involve in lymph node metastasis and advanced TNM stage. Correlation of tumor size with calcification, peripheral halo, vascularity, and blood supply do exist in PTMC. Ultrasound is of great value in the evaluation of PTMC.

Sonographic features of papillary thyroid microcarcinoma predicting high-volume central neck lymph node metastasis

ObjectiveTo study the correlations between the sonographic features of papillary thyroid microcarcinoma (PTMC) and the presence of high-volume lymph node metastasis. MethodMedical records of 2363 PTMC patients were reviewed form October 2013 to December 2015. All the patients with lymph node metastasis identified by histopathology were included. Preoperative sonographic features, such as multifocality, tumour size, echogenicity, calcification, vascularity of papillary microcarcinoma, and capsule invasion, were recorded. Univariate and multivariate analyses were performed to investigate the relationships between sonographic features and high-volume lymph node metastasis (number of metastatic lymph nodes >5). ResultsIn total, 152 patients had high-volume central lymph node metastasis (6.4%, 152/2363). Multiple logistic regression analysis showed that the preoperative ultrasonic features of microcalcifications (OR = 3.33, p = 0.022), larger tumour size (>7 mm) (OR = 2.802, p < 0.001), and capsule invasion (OR = 2.141, p = 0.006) were independent risk factors for high-volume lymph node metastasis in the central compartment of PTMC. ConclusionThe sonographic features of primary papillary microcarcinoma of the thyroid are correlated with high-volume central lymph node metastasis.

Clinicopathological characteristics of papillary thyroid microcarcinoma and risk factors for central lymph node metastasis

Objective: To analyze the clinicopathological characteristics of papillary thyroid microcarcinoma (PTMC) and risk factors for central lymph node metastasis(CLNM) in PTMC. Methods: The data of 900 patients with PTMC initially treated in our hospital from January 2004 to December 2015 were retrospectively analyzed. Chi-square test and Logistic regression analysis were performed to determine the risk factors for CLNM. Results: CLNM affected 162 (22.9%) of 707 patients treated with central lymph node dissection. Age, maximum tumor size, multifocality, bilaterality, and extracapsular spread (ECS) were significantly correlated with CLNM (all P<0.01). Age<45 years, maximum tumor size>5 mm, multifocality, bilaterality, and extracapsular spread were independently correlated with CLNM. Conclusion: A prophylactic central lymph node dissection should be considered in PTMC patients with age<45 years, maximum tumor size>5 mm, multifocality, bilaterality, and extracapsular spread.

Features of papillary thyroid microcarcinoma associated with lateral cervical lymph node metastasis.

Papillary thyroid microcarcinoma (PTMC) has an excellent prognosis with an indolent disease course. However, some PTMCs have an aggressive course with lateral cervical lymph node (LCLN) metastasis or distant metastasis. This study aimed to evaluate the pre-operative features of PTMC associated with LCLN metastasis. This retrospective cohort study with a nested, matched case-control design included 199 PTMC patients with LCLN metastasis at initial surgery (N1b group) and 196 PTMC patients without any LN metastasis or persistent disease (N0 NED group) as controls; primary tumour sizes were matched. Compared with the N0 NED group, the N1b group was younger (<50 years) and more likely to be male (P = 0·002 and P = 0·003, respectively). On pre-operative neck ultrasonography (US), N1b group PTMCs were more commonly associated with a location in the upper lobes of the thyroid, or in the subcapsular area and microcalcifications than N0 NED group PTMCs (all P < 0·001). An increase in the number of these features was significantly associated with a higher risk of LCLN metastasis (P < 0·001). Evaluation of the clinical and pre-operative US characteristics of 26 patients with confirmed LCLN recurrence after initial treatment of clinical N0 PTMCs revealed that the distribution of the number of suspicious features in these patients was similar to that of the N1b group. Papillary thyroid microcarcinomas in young (<50 years) or male patients, with an upper lobe or subcapsular location, and with microcalcification have a higher risk of LCLN metastasis. Individualized management according to the number of these suspicious features may be needed for small thyroid nodules.

Clinical analysis of 77 cases of papillary thyroid microcarcinoma

Objective To analyze the clinical characteristics of papillary thyroid microcarcinoma (PTMC). Methods One hundred and twenty nine patients preoperatively diagnosed as papillary thyroid carcinoma(PTC) or suspicious PTC by fine needle aspiration biopsy (FNAB) underwent thyroidectomy, and 127 cases were confirmed as PTC histopathologically, among whom 77 cases were microcarcinoma (60.6%). The clinical data of 77 PTMC cases were retrospectively analyzed with SPSS (20.0) statistical software. Results In 77 PTMC cases, BRAF gene detection was performed in 69 cases, 51 cases showed positive BRAF (73.9%) and 18 cases were negative. Among patients with positive BRAF, 17 cases had cervical lymph node metastasis (33.3%); and in those with negative BRAF, 5 cases had metastasis (5/18, χ2=0.189, P>0.05). In 31 patients with multiple lesions, 14 had cervical lymph node metastasis (45.2%); while in 46 patients with single lesion, 9 had metastasis (19.6%) (χ2=5.792, P<0.05). Conclusion Although PTMC growth is slow and occult, early lymph node metastasis is not rare, particularly for patients with multiple lesions. Key words: Thyroid neoplasma; Carcinoma, papillary; Biopsy, fine-needle; BRAF gene