Papillary thyroid microcarcinoma: the significance of high risk features

Papillary Thyroid Microcarcinoma: Differences between Lesions in Incidental and Nonincidental Settings-Considerations on These Clinical Entities and Personal Experience

Papillary thyroid microcarcinoma (PTMC) represents 35-40% of all papillary cancers; it is defined as a nodule ≤ 10 mm at the time of histological diagnosis. The clinical significance of PTMC is still controversial, and it may be discovered in two settings: incidental PTMC (iPTMC), in which it is identified postoperatively upon histological examination of thyroid specimens following thyroid surgery for benign disease, and nonincidental PTMC (niPTMC), in which it is diagnosed before surgery. While iPTMC appears to be related to mild behavior and favorable clinical outcomes, niPTMC may exhibit markers of aggressiveness. We retrospectively review our experience, selecting 54 PTMCs: 28 classified as niPTMC (52%) and 26 classified as iPTMC (48%). Patients with niPTMC showed significant differences, such as younger age at diagnosis (p < 0.001); a lower male/female ratio (p < 0.01); a larger mean nodule diameter (p < 0.001); and a higher rate of aggressive pathological findings, such as multifocality, capsular invasion and/or lymphovascular invasion (p = 0.035). Other differences found in the niPTMC subgroup included a higher preoperative serum TSH level, higher hospital morbidity and a greater need for postoperative iodine ablation therapy (p < 0.05), while disease-free long-term survival did not differ between subgroups (p = 0.331) after a mean follow-up (FU) of 87 months, with one nodal recurrence among niPTMCs. The differences between iPTMC and niPTMC were consistent: patients operated on for total thyroidectomy and showing iPTMC can be considered healed after surgery, and follow-up should be designed to properly calibrate hormonal supplementation; conversely, niPTMC may sometimes exhibit aggressive behavior, and so the FU regimen should be closer and aimed at early detection of cancer recurrence.

Thyroid Collision Tumors: The Presence of the Medullary Thyroid Carcinoma Component Negatively Influences the Prognosis

Thyroid collision tumors (TCTs) are rare pathological findings, representing <1% of thyroid cancers. This study aimed to compare the main pathological features of TCTs containing medullary thyroid carcinoma (MTC) and papillary thyroid carcinoma (PTC) components with MTC-only tumors and PTC-only tumors. Methods: The retrospective study included 69 cases diagnosed with TCTs (with simultaneous MTC and PTC components), MTC and PTC. All tumors were comparatively assessed for the classical histopathological prognostic features, including a new grading system for MTC. Results: The main component of TCTs had more frequent microscopic extrathyroidal extension (mETE) (p = 0.000), lymphovascular invasion (LVI) (p = 0.000), perineural invasion (PNI) (p = 0.044), and lymph node metastasis (p = 0.042). Additionally, the TCTs’ MTC component presented with more frequent LVI (p = 0.010). Comparing TCTs’ MTC and PTC components with MTC-only tumors and PTC-only tumors revealed that only the TCTs’ MTC components had statistically significant more frequent mETE (p = 0.010) than MTC-only tumors. When applied to the MTC component of TCTs, the pathological parameters of the new grading system of MTC showed no correlations with other microscopic or clinical aspects. Conclusion: Using classical pathological prognostic features, the comparative analysis revealed that the main TCTs’ component was more aggressive than the minor one. Contrary to PTCs, in TCTs, the medullary component was more aggressive than the papillary one, but also more aggressive than MTC-only tumors.

Differences in the clinical characteristics of papillary thyroid microcarcinoma located in the isthmus ≤5 mm and >5mm in diameter

Background

The optimal treatment of papillary thyroid microcarcinomas (PTMCs) located in the isthmus (iPTMCs) is still controversial. The purpose of this study was to compare the clinicopathologic features of patients with iPTMCs ≤5 mm and >5 mm in diameter after total thyroidectomy, and to identify the risk factors for recurrence in patients with iPTMCs.

Methods

A total of 102 iPTMC patients who underwent total thyroidectomy were reviewed retrospectively. The clinicopathologic characteristics of iPTMCs ≤5 mm group (n = 29) have been compared with a group >5 mm (n = 73). Univariate and multivariate Cox proportional hazard models served to identify risk factors associated with recurrence-free survival (RFS).

Results

Gender (p = 0.033), multifocality (p = 0.041), and central lymph node metastasis (CLNM) (p = 0.009) of patients in the ≤5 mm and >5 mm groups differed significantly. iPTMC patients with age <55 years, male, multiple tumor, and extrathyroidal extension showed comparatively more frequent of CLNM in >5 mm groups. Of the 102 patients, nine (8.8%) developed recurrence during follow-up (median: 49.5 months). The patients with recurrences had comparatively high rates of CLNM (p = 0.038), extranodal invasion (p = 0.018), and more MNCND (Metastasis Nodes for Central Neck dissection) (p = 0.020). A cutoff of MNCND >2.46 was established as the most sensitive and specific level for the prediction of recurrence based on receiver operating characteristic (ROC) curve analyses. Multivariate analysis showed that the number of MNCND ≥3 was an independent predictor of poor RFS (p = 0.028).

Conclusion

We have found that the recurrence rates are similar in patients with iPTMCs ≤5 mm and >5 mm. The iPTMCs >5 mm were more likely to be associated with pathological features such as multifocality and CLNM. The male gender, extrathyroidal extension, and CLNM were associated with recurrence of iPTMCs except for tumor size and multifocality. Higher risk of CLNM should be considered in iPTMC >5 mm when it reaches some risk factors. The numbers of MNCND ≥3 may be an independent predictor for recurrence, which could help clinicians for the decision of radioiodine administration and the modulation of follow-up modalities.

Population-level Outcomes of Early Thyroid Cancers: A Need to Revisit Current Practice

BACKGROUND

Early thyroid cancers have excellent long-term outcomes, yet the word "cancer" draws unnecessary apprehension. This study aimed to define when the recommendations for observation and surveillance may be extended to early thyroid cancers at the population level.

METHODS

Non-metastasized thyroid cancers ≤40 mm diameter were identified from the 1975-2016 Surveillance, Epidemiology and End Results (SEER) database. Causes of death were compared across demographic data. Disease-specific outcomes were compared to the age-adjusted healthy United States (US) population. Survival estimates were computed using Kaplan-Meier and compared using the Cox proportional hazard model. Dynamic benchmarks impacting disease-specific overall survival were determined by decision tree modeling and tested by the Cox model.

RESULTS

Of the 28,728 thyroid cancers included in this study, 98.4% underwent some form of thyroid-specific treatment and were followed for a maximum of 10.9 years. This group had a 4.3% mortality rate at the end of follow-up (10.9 years maximum), with 13 times more deaths attributed to competing risks rather than thyroid cancer (stage T1a versus stage T1b, P=1.000; T1 versus T2, P<0.001). Among the untreated T1a or T1b tumors, the risk of disease-specific death was 21 times lower than death due to other causes. There was no significant difference between T1a and T1b tumors nor across sex. The age-adjusted risk of death for the healthy US population was higher than for the population with thyroid cancer. Dynamic categorization demonstrated worsening outcomes up to 73 years, uninfluenced by sex or tumor size. For patients over 73 years of age, only tumors >26 mm impacted outcomes.

CONCLUSION

Based on the current data, T1a and T1b nodules have similar survival outcomes and are not significantly impacted even when left untreated. Multi-institutional prospective studies are needed to confirm these findings so that current observation and surveillance recommendations can be extended to certain T1 thyroid nodules.

Systematic analysis of the lysine malonylome in Sanghuangporus sanghuang

Background

Sanghuangporus sanghuang is a well-known traditional medicinal mushroom associated with mulberry. Despite the properties of this mushroom being known for many years, the regulatory mechanisms of bioactive compound biosynthesis in this medicinal mushroom are still unclear. Lysine malonylation is a posttranslational modification that has many critical functions in various aspects of cell metabolism. However, at present we do not know its role in S. sanghuang. In this study, a global investigation of the lysine malonylome in S. sanghuang was therefore carried out.

Results

In total, 714 malonyl modification sites were matched to 255 different proteins. The analysis indicated that malonyl modifications were involved in a wide range of cellular functions and displayed a distinct subcellular localization. Bioinformatics analysis indicated that malonylated proteins were engaged in different metabolic pathways, including glyoxylate and dicarboxylate metabolism, glycolysis/gluconeogenesis, and the tricarboxylic acid (TCA) cycle. Notably, a total of 26 enzymes related to triterpene and polysaccharide biosynthesis were found to be malonylated, indicating an indispensable role of lysine malonylation in bioactive compound biosynthesis in S. sanghuang.

Conclusions

These findings suggest that malonylation is associated with many metabolic pathways, particularly the metabolism of the bioactive compounds triterpene and polysaccharide. This paper represents the first comprehensive survey of malonylation in S. sanghuang and provides important data for further study on the physiological function of lysine malonylation in S. sanghuang and other medicinal mushrooms.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12864-021-08120-0.

Papillary thyroid microcarcinomas that metastasize to lymph nodes

PURPOSE

We aimed to determine clinicopathological features that can predict lymph node metastasis (LNM) in papillary thyroid microcarcinomas (PTMC).

METHODS

Medical records of 872 patients with papillary thyroid cancer >1 cm (PTC > 1 cm) and 1184 patients with papillary thyroid microcancer (PTMC) (≤1 cm) were reviewed retrospectively. Demographical, clinical and histopathological features of (PTC > 1 cm) and PTMC were compared. Association between clinicopathological features and LNM in PTMC was investigated.

RESULTS

The median age of patients with PTMC was significantly higher than patients with PTC > 1 cm (49 vs 46 years old, p < 0.001). Multifocality, capsular invasion, vascular invasion, extrathyroidal extension (ETE) and LNM were more frequent in patients with PTC > 1 cm compared to patients with PMTC (p < 0.001 for each). In PTMC group, those with LNM had significantly higher proportion of multifocality, capsular invasion, vascular invasion and ETE compared to those without LNM (p = 0.007, <0.001, p = 0.011 and p < 0.001, respectively). Multifocality and ETE were significant factors for LNM with logistic regression analysis. Multifocality increased the risk of LNM by 1.737 times (95% CI: 1.079-2.979) and ETE increased the risk by 3.528 times (95%: 1.914-6.503). Primary tumor diameter ≥ 5.75 mm was predictive for LNM with a sensitivity of 0.782 and a specificity of 0.517 in PTMC.

CONCLUSIONS

LNM should be investigated more carefully in patients with PTMC in the presence of tumor diameter ≥ 5.75 mm, multifocality or ETE.

Investigation and management of papillary thyroid microcarcinoma - a Scottish regional case series and literature review

BACKGROUND AND AIMS

Papillary thyroid microcarcinoma is defined as papillary thyroid cancer with a diameter of ≤1 cm. Despite its prevalence, there is wide variation in practice in the investigation and management of patients with papillary thyroid microcarcinoma throughout the UK and internationally. The primary aim of this paper is to describe the experience of investigation and management in a Scottish health board over the past 10 years.

METHODS AND RESULTS

Retrospective analysis of thyroidectomy and hemithyroidectomy resection samples from March 2009 to March 2020. 532 specimens were reviewed and 20 patients with PTMC were identified. 12 patients had an incidental finding of PTMC. Median U score- 3, Median Thy score- 2.5 for dominant or radiologically suspicious nodules. 8 specimens demonstrated aggressive histopathological features. 1 patient with positive nodal disease in the neck and 0 patients with positive nodal disease in the thorax on CT Neck and Chest.

CONCLUSION

Here we report the first UK Cohort describing the radiological investigation and management of papillary thyroid microcarcinoma. The results of our study are in accordance with a recent meta-analysis which found 4% nodal disease and 0.025% distant metastasis at time of presentation in patients with PTMC.

Enemy Beyond the Wall: Clinicopathological Features of Intrathyroidal Papillary Thyroid Carcinoma (T1-T3a) That Metastasize to Lymph Nodes Without Extrathyroidal Extension

The aim of this study was to determine the clinicopathological features of papillary thyroid carcinomas (PTC) without extrathyroidal extension (ETE) and with lymph node metastasis (LNM). PTC > 1 cm increased the risk of LNM by 2.161 times compared to papillary thyroid microcarcinoma. The risk increased by 3.774 times in males and 1.553 times in the presence of multifocality. Presence of vascular invasion (VI) increased the risk of LNM by 3.093 times in patients without capsular invasion (CI). Clinicians should be careful about possible LNM in patients with large primary tumor diameter, multifocal tumors, CI and VI.

Microcarcinoma papilar de tiroides: ¿es adecuada la selección para protocolo de vigilancia activa?

Introducción. Los microcarcinomas papilares de tiroides son tumores de hasta 10 mm en su diámetro mayor. Su tratamiento es sujeto de debate y se propone, desde seguimiento clínico, hasta intervención quirúrgica temprana. Este estudio buscó identificar factores de riesgo relacionados con compromiso ganglionar, que permitan una mejor selección de los pacientes en nuestro medio, en quienes se propone manejo quirúrgico inmediato o vigilancia activa, en consonancia con la clasificación del riesgo de progresión. Métodos. Estudio de cohorte analítica ambispectiva que incluyó pacientes con microcarcinoma papilar de tiroides llevados a tiroidectomía más vaciamiento central. Se caracterizó la población y se realizó un análisis de regresión logística multivariado para definir factores preoperatorios asociados al compromiso ganglionar. Adicionalmente, se evaluó de manera retrospectiva la eventual asignación a grupos de riesgo de progresión, según los criterios de Miyauchi, y su comportamiento respecto al estado nodal. Resultados. Se incluyeron 286 pacientes. El 48,9 % presentó compromiso ganglionar, y de estos, el 33,5 % presentó compromiso ganglionar significativo, que modificó su clasificación de riesgo de recaída. De estos últimos, el 59,5 % hubiesen sido manejados con vigilancia activa, según los criterios propuestos por Miyauchi. Se identificó que la edad menor de 55 años, los ganglios sospechosos en la ecografía y los nódulos mayores de 5 mm, se relacionan con compromiso ganglionar significativo. Discusión. El manejo quirúrgico inmediato parece ser una opción adecuada para pacientes con sospecha de compromiso ganglionar en ecografía preoperatoria, pacientes menores de 55 años y nódulos mayores de 5 mm. Es posible que los actuales criterios para definir vigilancia activa no seleccionen adecuadamente a los pacientes en nuestro medio.

YY1-induced up-regulation of FOXE1 is negatively regulated by miR-129-5p and contributes to the progression of papillary thyroid microcarcinoma

BACKGROUND

Papillary thyroid microcarcinoma (PTM) belongs to papillary carcinomas whose length is about 1.0 cm. According to previous studies, FOXE1 is a transcription factor involved in the progression of papillary thyroid carcinoma (PTC). However, its detailed upstream mechanism remains unknown in PTM.

OBJECTIVE

Our study aimed at detecting and verifying the up-regulation of FOXE1 in PTM cell lines.

METHODS

FXOE1 expression was detected in PTM and normal cells through RT-qPCR. Loss-of-function experiments were conducted to identify the effect of silenced FOXE1 on cell proliferation, apoptosis, migration and invasion. Mechanism experiments were carried out to explore the upstream molecular mechanism of FOXE1.

RESULTS

Knockdown of FOXE1 could lead to the inhibition on cell proliferation, migration and invasion while positively regulating cell apoptosis. Importantly, Yin-Yang-1 (YY1) could boost the transcription of FOXE1, thereby upregulating FOXE1. Also, the binding potential of miR-129-5p to FOXE1 was identified in PTM cells and MiR-129-5p could target FOXE1. In addition, the cellular processes in PTM were hindered with the increase of miR-129-5p expression level.

CONCLUSION

Our research suggested that the up-regulation of FOXE1 is regulated by YY1 and miR-129-5p, which may contribute to PTM progression.

Genomic and Transcriptomic Characteristics According to Size of Papillary Thyroid Microcarcinoma

It is controversial as to whether papillary thyroid microcarcinoma (PTMC) has some genomic and transcriptomic characteristics that differentiate between an early-stage lesion that would eventually evolve into the larger papillary thyroid cancer (PTC), and an occult indolent cancer in itself. To investigate this, we comprehensively elucidated the genomic and transcriptomic landscapes of PTMCs of different sizes, using a large-scaled database. This study included 3435 PTCs, 1985 of which were PTMCs. We performed targeted next-generation sequencing for 221 PTCs and integrated these data with the data including The Cancer Genome Atlas (TCGA) project. The frequency of v-raf murine sarcoma viral oncogene homolog B (BRAF)^V600E mutation was higher in PTMCs >0.5 cm than that in very small PTMCs (≤0.5 cm) and decreased again in PTCs >2 cm. Among PTMCs, the prevalence of mutations in rat sarcoma (RAS) and telomerase reverse transcriptase (TERT) promoter was not significantly different according to their size, but lower than in large PTCs. There was no change in the tumor mutational burden, the number of driver mutations, and transcriptomic profiles with tumor size, among PTMCs and all PTCs. Although a few genes with differential expression and TERT promoter mutations were found in a few PTMCs, our findings showed that there were no useful genomic or transcriptomic characteristics for the prediction of the future progression of PTMC.

Papillary thyroid microcarcinoma presenting as a metastasis to the brain

The brain is a particularly rare site of metastasis from papillary microcarcinoma, with only few cases described in the literature. We present a case of 59-year-old man who presented with seizures and dysphasia due to left frontal lobe cystic mass, which was excised and turned out on histopathology to be of thyroid origin. Total thyroidectomy was performed and histology showed multifocal papillary microcarcinoma with the largest focus of 3mm with no other adverse features. The patient had ablative radioactive iodine postoperatively, with subsequent exit scan showing no uptake in the brain. Follow-up brain magnetic resonance imaging showed continuous regression of the surgical cavity. Although rare, such cases should be aggressively treated and followed up over the long term, because of reported associated high mortality.

Lymph Node Metastasis and Extrathyroidal Extension in Papillary Thyroid Microcarcinoma in Cyprus: Suspicious Subcentimeter Nodules Should Undergo FNA When Multifocality is Suspected

Objective

To determine the prevalence of lymph node (LN) metastasis and extrathyroidal extension (ETE) in patients with papillary thyroid microcarcinoma (PTMC) in Cyprus and to evaluate the role of preoperative ultrasound (U/S) examination.

Methods

A retrospective study of 102 patients who underwent thyroidectomy for PTMC in a 2-year period. Preoperatively, all patients had a thyroid and neck U/S examination with LN mapping. Tumor size according to the largest diameter, number of foci, LN metastasis, and ETE data was collected from the histopathological report and was compared to the preoperative U/S reports.

Results

LN metastasis was present in 23.5% of patients. 15.7% had central, 3.9% had lateral, and 3.9% had both central and lateral LN metastasis. ETE was present in 27.5% of patients. 21.6% had multifocal disease, and in this group, 40.9% had LN metastasis and 36.4% had ETE. Multifocality (p = 0.03), size of tumor (p = 0.05), and ETE (p ≤ 0.001) were significantly associated with LN metastasis. The prevalence of LN metastasis in multifocal PTMC ≤5 mm was the same with multifocal PTMC >5 mm. The preoperative U/S sensitivity for the suspicious lateral neck and central LN was 100%, and the specificity was 100%. The preoperative U/S sensitivity for nodules suspicious for ETE was 53.6%, and the specificity was 100%.

Conclusion

The presence of LN metastasis and ETE in our PTMC patients in Cyprus is frequent. Neck U/S mapping is a highly reliable and accurate tool in identifying metastatic nodes. LN metastasis is associated with ETE and multifocality. Suspicious subcentimeter nodules should undergo FNA irrespective of size when multifocality is suspected.

Predictive Factors of Recurrence in Patients with Differentiated Thyroid Carcinoma: A Retrospective Analysis on 579 Patients

Differentiated thyroid carcinoma (DTC) is usually associated with a favorable prognosis. Nevertheless, up to 30% of patients present a local or distant recurrence. The aim of this study was to assess the incidence of recurrence after surgery for DTC and to identify predictive factors of recurrence. We included in this retrospective study 579 consecutive patients who underwent thyroidectomy for DTC from 2011 to 2016 at our institution. We observed biochemical or structural recurrent disease in 36 (6.2%) patients; five-year disease-free survival was 94.1%. On univariate analysis, male sex, histotype, lymph node yield, lymph node metastasis, extrathyroidal invasion and multicentricity were associated with significantly higher risk of recurrence, while microcarcinoma was correlated with significantly lower risk of recurrence. On multivariate analysis, only lymph node metastases (OR 4.724, p = 0.012) and microcarcinoma (OR 0.328, p = 0.034) were detected as independent predictive factors of recurrence. Postoperative management should be individualized and commensurate with the risk of recurrence: Patients with high-risk carcinoma should undergo strict follow-up and aggressive treatment. Furthermore, assessment of the risk should be repeated over time, considering individual response to therapy.

Coexistent papillary thyroid carcinoma diagnosed in surgically treated patients for primary versus secondary hyperparathyroidism: same incidence, different characteristics

BACKGROUND

The coexistence of hyperparathyroidism and thyroid cancer presents important diagnostic and management challenges. With minimally invasive parathyroid surgery trending, preoperative thyroid imaging becomes more important as concomitant thyroid and parathyroid lesions are reported. The aim of the study was to evaluate the rate of thyroid cancer in patients operated for either primary (PHPT) or secondary hyperparathyroidism (SHPT).

METHODS

Our retrospective study included PHPT and SHPT patients submitted to parathyroidectomy and, when indicated, concomitant thyroid surgery between 2010 and 2017.

RESULTS

Parathyroidectomy was performed in 217 patients: 140 (64.5%) for PHPT and 77 (35.5%) for SHPT. Concomitant thyroid surgery was performed in 75 patients with PHPT (53.6%), and 19 papillary thyroid carcinomas (PTC) were found, accounting for 13.6% from all cases with PHPT and 25.3% from PHPT cases with concomitant thyroid surgery. Thirty-one of operated SHPT patients (40.3%) also underwent thyroid surgery and 9 PTC cases were diagnosed (11.7% of all SHPT patients and 29% of patients with concomitant thyroid surgery). We found differences between PHPT and SHPT patients (p < 0.001) with respect to age (54.6 ± 13y versus 48.8 ± 12y), female-to-male ratio (8:1 versus ~ 1:1), surgical technique (single gland parathyroidectomy in 82.8% PHPT cases; versus subtotal parathyroidectomy in 85.7% SHPT cases) and presurgical PTH (357.51 ± 38.11 pg/ml versus 1020 ± 161.38 pg/ml). Morphopathological particularities, TNM classification and multifocality incidence of PTC were similar in the two groups. All PTC from patients with SHPT were thyroid microcarcinomas (TMC, i.e. tumors with a diameter smaller than 1 cm), whereas seven out of the 19 cases with PTC and PHPT were larger than 1 cm.

CONCLUSIONS

PTC was frequently and similarly associated with both PHPT and SHPT irrespective of presurgical PTH levels. Thyroid tumors above 1 cm were found only in patients with PHPT. Investigators should focus also on associated thyroid nodular pathology in patients with PHPT.

The increasing prevalence of chronic lymphocytic thyroiditis in papillary microcarcinoma

Although the incidence of some malignancy has decreased over the recent years, this is not the case of papillary thyroid microcarcinoma (PTMC), whose incidence has increased worldwide. Most PTMC are found incidentally after histological examination of specimens from surgery for benign thyroid disease. Hashimoto's thyroiditis, whose incidence has also increased, coexists in about one in three PTMC patients. Three different mechanisms have been proposed to clarify the association between chronic lymphocytic thyroiditis and PTMC, namely tumor development/growth by: (i) TSH stimulation, (ii) expression of certain proto-oncogenes, (iii) chemokines and other molecules produced by the lymphocytic infiltrate. Whether Hashimoto's thyroiditis protects against lymph node metastasis is debated. Overall, autommune thyroiditis seems to contribute to the favorable prognosis of PTMC. Major limitations of the studies so far performed include: (i) retrospective design, (ii) limited statistical power, (iii) high risk of selection bias, (iv) and predominant Asian ethnicity of patients. Full genetic profiling of both diseases and identification of environmental factors capable to trigger them, as well as well-powered prospective studies on different ethnical groups, may help understand their causal association and why their frequencies are continuing raising.

Current Advances in Thyroid Cancer Management. Are We Ready for the Epidemic Rise of Diagnoses?

A rising incidence of thyroid cancers (TCs) mainly small tumors, observed during recent years, lead to many controversies regarding treatment strategies. TCs represent a distinct molecular background and clinical outcome. Although in most cases TCs are characterized by a good prognosis, there are some aggressive forms, which do not respond to standard treatment. There are still some questions, which have to be resolved to avoid dangerous simplifications in the clinical management. In this article, we focused on the current advantages in preoperative molecular diagnostic tests and histopathological examination including noninvasive follicular thyroid neoplasm with papillary-like nuclear features (NIFTP). We discussed the controversies regarding the extent of thyroid surgery and adjuvant radioiodine therapy, as well as new treatment modalities for radioiodine-refractory differentiated thyroid cancer (RR-DTC). Considering medullary thyroid cancer (MTC), we analyzed a clinical management based on histopathology and RET (ret proto-oncogene) mutation genotype, disease follow-up with a special attention to serum calcitonin doubling time as an important prognostic marker, and targeted therapy applied in advanced MTC. In addition, we provided some data regarding anaplastic thyroid cancer (ATC), a highly lethal neoplasm, which lead to death in nearly 100% of patients due to the lack of effective treatment options.

Relationships between clinicopathological prognostic factors in papillary thyroid microcarcinoma: a refined analysis based on 428 cases

A clear definition of the prognostic factors for papillary thyroid microcarcinoma (PTMC) is still debatable, as the tumor characteristics which indicate a high risk of metastasis are little known. We investigated the clinicopathological profile of a large group of PTMC, aiming to ascertain possible relationships between a set of clinicopathological characteristics and four parameters expressing tumor extension and aggressiveness (namely lympho-vascular invasion, thyroid capsule invasion, extrathyroidal extension and lymph node metastasis). For 428 patients, the following data were retrospectively documented: sex, age, tumor size, histological variant, associated thyroid pathology, location (subcapsular, intraparenchymal), unilateral or bilateral involvement, number of foci, lympho-vascular invasion, thyroid capsule invasion, extrathyroidal extension and lymph node metastasis. Data were analyzed using univariate and multivariate logistic regression analysis. Multivariate analysis confirmed that the tumor size is a negative prognostic factor for lympho-vascular invasion, thyroid capsule invasion, extrathyroidal extension and lymph node metastasis. We also demonstrated a strong relationship between the subcapsular location and lympho-vascular and capsule invasion, and extrathyroidal extension. The multifocality was correlated only with thyroid capsule invasion and extrathyroidal extension. Regarding the histological variants, the only validated correlation was between the oncocytic variant and extrathyroidal extension. Our work contributes to the validation of PTMC prognostic factors, useful in stratification of PTMC in high or low risk classes, and able to explain the behavioral differences in the tumor development.