Trends in Diagnosis of Noninvasive Follicular Thyroid Neoplasm With Papillarylike Nuclear Features and Total Thyroidectomies for Patients With Papillary Thyroid Neoplasms

Management of Incidental Thyroid Nodules

Thyroid nodules are widely prevalent, and often discovered incidentally. Malignancy rates are low for incidental thyroid nodules, and overall outcomes are favorable regardless of diagnosis. Patients with thyroid nodules should be evaluated with TSH levels followed by ultrasound of the thyroid and cervical lymph nodes. It is important to recognize sonographic features suspicious for thyroid malignancy and obtain biopsies when indicated according to major society guidelines. The Bethesda System for Reporting Thyroid Cytopathology along with molecular testing can help guide management decisions regarding thyroid nodules. Surgical resection and other emerging technologies are safe and effective for the treatment of thyroid nodules needing intervention.

Comprehensive analysis of cellular senescence and immune microenvironment in papillary thyroid carcinoma

Senescence-induced therapy was previously considered as an effective treatment for tumors, and cellular senescence was initially regarded as an effective mechanism against cancer. However, whether cell senescence-related genes can be used to predict the prognosis of papillary thyroid carcinoma (PTC) and immunotherapy remains unclear. We developed and validated a cell senescence-related signature (CSRS) by analyzing the gene expression of 278 genes related to cellular senescence in 738 patients with PTC. Additionally, further analysis showed that CSRS was a reliable predictor of patient outcomes in combination with immune checkpoint expression and drug susceptibility, and patients with high risk scores may benefit from immunotherapy. The findings of this study demonstrate that CSRS serves as an immunotherapeutic response and prognosis biomarker affecting the tumor immune microenvironment of PTC.

Challenges in Encapsulated Follicular-Patterned Tumors: How Much Is Enough? Evaluation of Nuclear Atypia, Architecture, and Invasion

Thyroid pathology is notoriously fraught with high interobserver variability, and follicular-patterned tumors are among some of the most challenging to assess accurately and reproducibly. Given that encapsulated or well-circumscribed follicular-patterned tumors often have similar molecular profiles, that is, frequent RAS or RAS-like alterations, the diagnosis usually relies on histopathologic examination alone. Unfortunately, many of the features that are used for diagnosis and prognosis of these tumors have long been controversial and frequently debated topics, both due to their subjectivity and their evolving (or not yet resolved) definitions. In more recent years, the introduction of noninvasive follicular thyroid neoplasm with papillary-like nuclear features has added further complexity to this discussion. In particular, the criteria and significance of nuclear features of papillary thyroid carcinoma, architectural patterns, and invasive growth still pose significant diagnostic challenges and confusion. This review explores some of the challenges in evaluating encapsulated follicular-patterned tumors, focusing on those histologic elements.

Non-invasive follicular thyroid neoplasm with papillary-like nuclear feature: clinical, pathological, and molecular update 5 years after the nomenclature revision

The term non-invasive follicular thyroid neoplasm with papillary-like nuclear features (NIFTP) was proposed in 2016 and incorporated as a new entity in the World Health Organization (WHO) classification of tumours of endocrine organs in 2017. Since then, there has been debate regarding the histological criteria for the diagnosis, the need for molecular studies or the risk of lymph node metastasis or recurrence associated with this entity. Over the years, the concept of NIFTP evolved, now including both small (<1 cm) and large (>4 cm) tumours and oncocytic lesions. On the other hand, recent data on NIFTP in the setting of thyroid follicular nodular disease or frequent coexistence of malignant tumours raised concerns regarding the follow-up of these patients. Today, both pathologists and clinicians still face several challenges in the diagnosis, treatment, and follow-up of patients with NIFTP.

Non-invasive follicular neoplasm with papillary-like nuclear features: a challenging and infrequent entity in Argentina

PURPOSE

Non-invasive encapsulated follicular variant of papillary thyroid cancer was reclassified as non-invasive follicular thyroid neoplasm with papillary-like nuclear features (NIFTP). These neoplasms have an extremely low malignant potential. The aim of this study was (1) to assess the prevalence of NIFTP in patients with papillary thyroid carcinoma, (2) to evaluate their outcomes, and (3) to determine their molecular profile.

METHODS

Multicenter, descriptive, retrospective study. Patients with papillary thyroid cancer diagnosed from January 2006 to December 2016 from 11 referral centers were included. Diagnosis of NIFTP was based on criteria described by Nikiforov et al. in 2018. At least two pathologists agreed on the diagnosis. Two thousand six hundred and seventy-seven papillary thyroid cancer patients were included; 456 (17%) of them were follicular variant papillary thyroid cancer, and 30 (1.12%) fulfilled diagnostic criteria for NIFTP.

RESULTS

Each of the 30 included patients underwent a total thyroidectomy, and 50% were treated with radioiodine (median dose 100 mCi). After a median follow-up of 37 months, 84% of patients had an excellent response, 3% had an indeterminate response and data was missing in the remaining 13%. No metastatic lymph nodes, distant metastases or recurrences were found. RAS mutations were detected in 4 patients (13%).

CONCLUSION

The prevalence of NIFTP in our series is amongst the lowest reported. Excellent outcomes of patients underscore their low malignant potential. Molecular findings differ from other series, probably related to environmental or ethnic features of our population and the meticulous criteria for diagnosing NIFTP.

Complication Rates of Total Thyroidectomy vs Hemithyroidectomy for Treatment of Papillary Thyroid Microcarcinoma: A Systematic Review and Meta-analysis

Importance

Papillary thyroid microcarcinomas (PTMCs) have been associated with increased thyroid cancer incidence in recent decades. Total thyroidectomy (TT) has historically been the primary treatment, but current guidelines recommend hemithyroidectomy (HT) for select low-risk cancers; however, the risk-benefit ratio of the 2 operations is incompletely characterized.

Objective

To compare surgical complication rates between TT and HT for PTMC treatment.

Data Sources

SCOPUS, Medline via the PubMed interface, and the Cochrane Central Register of Controlled Trials (CENTRAL); through January 1, 2021, with no starting date restriction. Terms related to papillary thyroid carcinoma and its treatment were used for article retrieval. This meta-analysis used the Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA) guideline and was written according to the Meta-analysis of Observational Studies in Epidemiology (MOOSE) proposal.

Study Selection

Original investigations of adults reporting primary surgical treatment outcomes in PTMC and at least 1 complication of interest were included. Articles evaluating only secondary operations or non-open surgical approaches were excluded. Study selection, data extraction, and risk of bias assessment were performed by 2 independent reviewers and conflicts resolved by a senior reviewer.

Data Extraction and Synthesis

Pooled effect estimates were calculated using a random-effects inverse-variance weighting model.

Main Outcomes and Measures

Cancer recurrence and site, mortality (all-cause and disease-specific), vocal fold paralysis, hypoparathyroidism, and hemorrhage/hematoma. Risk of bias was assessed using the McMaster Quality Assessment Scale of Harms scale.

Results

In this systematic review and meta-analysis, 17 studies were analyzed and included 1416 patients undergoing HT and 2411 patients undergoing TT (HT: pooled mean [SD] age, 47.0 [10.0] years; 1139 [84.6%] were female; and TT: pooled mean [SD] age, 48.8 [10.0] years; 1671 [77.4%] were female). Patients undergoing HT had significantly lower risk of temporary vocal fold paralysis compared with patients undergoing TT (3.3% vs 4.5%) (weighted risk ratio [RR], 0.4; 95% CI, 0.2-0.7), temporary hypoparathyroidism (2.2% vs 21.3%) (weighted RR, 0.1; 95% CI, 0.0-0.4), and permanent hypoparathyroidism (0% vs 1.8%) (weighted RR, 0.2; 95% CI, 0.0-0.8). Contralateral lobe malignant neoplasm recurrence was 2.3% in the HT group, while no such events occurred in the TT group. Hemithyroidectomy was associated with a higher overall recurrence rate (3.8% vs 1.0%) (weighted RR, 2.6; 95% CI, 1.3-5.4), but there was no difference in recurrence in the thyroid bed or neck.

Conclusions and Relevance

The results of this systematic review and meta-analysis help characterize current knowledge of the risk-benefit ratio of HT vs TT for treatment of PTMC and provide data that may have utility for patient counseling surrounding treatment decisions.