Clinical and pathologic features of "sporadic" papillary thyroid carcinoma registered in the years 2005 to 2008 in children and adolescents of Belarus

Management of aggressive variants of papillary thyroid cancer

PURPOSE OF REVIEW

The aim of this study was to provide a timely and relevant review of the latest findings and explore appropriate management of aggressive variants of papillary thyroid cancer (AVPTC).

RECENT FINDINGS

In general, AVPTCs tend to exhibit more invasive characteristics, a lack of responsiveness to radioiodine, increased occurrences of regional spreading, distant metastases and higher mortality rates. Meanwhile, each variant showcases unique clinical and molecular profiles.

SUMMARY

Given the elevated risk of recurrence postsurgery, a more aggressive strategy may be necessary when suspected preoperatively, particularly for those presenting with invasive features. Decision on the extent of surgical treatment and adjuvant therapy is individualized and made by experienced clinicians and multidisciplinary teams based on the clinical presentation, presence of aggressive features and molecular profile. Future studies on development of personalized medicine and molecular target therapy may offer tailored treatment options.

Molecular Genetics of Diffuse Sclerosing Papillary Thyroid Cancer

CONTEXT

Diffuse sclerosing papillary thyroid cancer (DSPTC) is rare, with limited data on its molecular genetics.

OBJECTIVE

We studied the molecular genetics of a cohort of DSPTC.

METHODS

DNA was isolated from paraffin blocks of 22 patients with DSPTC (15 females, 7 males, median age 18 years, range 8-81). We performed polymerase chain reaction-based Sanger sequencing and a next-generation sequencing (NGS) gene panel to characterize the genomic landscape of these tumors. We classified genetic alterations to definitely or probably pathogenic. Definitely pathogenic are genetic alterations that are well known to be associated with PTC (e.g., BRAFV600E). Probably pathogenic are other alterations in genes that were reported in The Cancer Genome Atlas or the poorly differentiated and anaplastic thyroid cancer datasets.

RESULTS

Three tumors were tested only by Sanger sequencing and were negative for BRAFV600E, HRAS, KRAS, NRAS, TERT promoter, PTEN, and PIK3CA mutations. The other 19 tumors tested by NGS showed definitely pathogenic alterations in 10 patients (52.6%): 2/19 (10.5%) BRAFV600E, 5/19 (26.3%) CCDC6-RET (RET/PTC1), 1/19 (5.3%) NCOA4-RET (RET/PTC3), 1/19 (5.3%) STRN-ALK fusion, and 2/19 (10.6%) TP53 mutations. Probably pathogenic alterations occurred in 13/19 tumors (68.4%) and included variants in POLE (31.6%), CDKN2A (26%), NF1 (21%), BRCA2 (15.8%), SETD2 (5.3%), ATM (5.3%), FLT3 (5.3%), and ROS1 (5.3%). In 1 patient, the gene panel showed no alterations. No mutations were found in the RAS, PTEN, PIK3CA, or TERT promoter in all patients. There was no clear genotype/phenotype correlation.

CONCLUSION

In DSPTC, fusion genes are common, BRAFV600E is rare, and other usual point mutations are absent. Pathogenic and likely pathogenic variants in POLE, NF1, CDKN2A, BRCA2, TP53, SETD2, ATM, FLT3, and ROS1 occur in about two-thirds of DTPTC.

Paediatric differentiated thyroid carcinoma: a UK National Clinical Practice Consensus Guideline

This guideline is written as a reference document for clinicians presented with the challenge of managing paediatric patients with differentiated thyroid carcinoma up to the age of 19 years. Care of paediatric patients with differentiated thyroid carcinoma differs in key aspects from that of adults, and there have been several recent developments in the care pathways for this condition; this guideline has sought to identify and attend to these areas. It addresses the presentation, clinical assessment, diagnosis, management (both surgical and medical), genetic counselling, follow-up and prognosis of affected patients. The guideline development group formed of a multi-disciplinary panel of sub-speciality experts carried out a systematic primary literature review and Delphi Consensus exercise. The guideline was developed in accordance with The Appraisal of Guidelines Research and Evaluation Instrument II criteria, with input from stakeholders including charities and patient groups. Based on scientific evidence and expert opinion, 58 recommendations have been collected to produce a clear, pragmatic set of management guidelines. It is intended as an evidence base for future optimal management and to improve the quality of clinical care of paediatric patients with differentiated thyroid carcinoma.

Aggressive variants of follicular cell-derived thyroid carcinoma: an overview

PURPOSE

The incidence of thyroid carcinoma has increased globally in the past years. Papillary thyroid carcinoma (PTC) is the most frequent neoplasm of the thyroid gland comprehending the 90% of the thyroid carcinoma and has an indolent clinical behaviour. However, some variants of follicular cell-derived thyroid carcinoma, including variants of classic of PTC, have been identified that show a more aggressive biological behaviour. An accurate diagnosis of these entities is crucial for planning a more aggressive treatment and improving patients' prognosis of patients. The aim of this review is to present the main clinical, histological, and molecular features of aggressive variants of follicular cell-derived thyroid carcinoma, and to provide useful histological parameters for determining the most suitable therapeutic strategy for patients affected by these forms.

RESULTS

Variants of classic PTC such as the diffuse sclerosing variant (DSV), the tall cell variant (TCV), the columnar cell variant (CCV), the solid/trabecular variant (STV) and the hobnail variant (HV), and other variants of follicular cell-derived thyroid carcinoma, such as poorly differentiated thyroid carcinoma (PDTC), and anaplastic thyroid carcinoma (ATC), are associated with aggressive behaviour.

CONCLUSIONS

The correct identification and diagnosis of aggressive variants of follicular cell-derived thyroid carcinoma is important, as they allow the clinician to adopt the most refined therapeutic strategies in order to the survival of the patients.

Genetic Landscape of Papillary Thyroid Carcinoma and Nuclear Architecture: An Overview Comparing Pediatric and Adult Populations

Thyroid cancer is a rare malignancy in the pediatric population that is highly associated with disease aggressiveness and advanced disease stages when compared to adult population. The biological and molecular features underlying pediatric and adult thyroid cancer pathogenesis could be responsible for differences in the clinical presentation and prognosis. Despite this, the clinical assessment and treatments used in pediatric thyroid cancer are the same as those implemented for adults and specific personalized target treatments are not used in clinical practice. In this review, we focus on papillary thyroid carcinoma (PTC), which represents 80-90% of all differentiated thyroid carcinomas. PTC has a high rate of gene fusions and mutations, which can influence the histologic subtypes in both children and adults. This review also highlights telomere-related genomic instability and changes in nuclear organization as novel biomarkers for thyroid cancers.

Papillary Thyroid Cancer-Aggressive Variants and Impact on Management: A Narrative Review

Introduction

Aggressive variants of papillary thyroid cancer (PTC) have been described with increasing frequency. These variants include diffuse sclerosing variant, tall cell variant, columnar cell variant, solid variant, and hobnail variant.

Methods

We have performed a review of the more aggressive variants of PTC with respect to main characteristics, histological and molecular features, and the consequences that the knowledge of these variants should have in the treatment of the patients.

Results

At the present time, we do not know the prognostic value of these aggressive PTC variants. The extent of the surgical treatment and adjuvant therapy necessary should be decided on the basis of the extent of the tumor at presentation and the opinion of experienced clinicians.

Conclusion

These aggressive variants should be known by clinicians, to avoid underdiagnosis, and treated according to the latest recommendations in the literature.

Sporadic pediatric papillary thyroid carcinoma harboring the ETV6/NTRK3 fusion oncogene in a 7-year-old Japanese girl: a case report and review of literature

BACKGROUND

There have been great concerns about pediatric thyroid cancers after the accident at the Fukushima Daiichi Nuclear Power Plant in 2011.

CASE PRESENTATION

We report a case of a 7-year-old Japanese girl with sporadic papillary thyroid carcinoma (PTC) harboring an ETV6/NTRK3 rearrangement. The patient presented with tumors in both lobes and underwent thyroidectomy followed by radioactive iodine (RAI) ablation. Histopathology showed a classic type of PTC with cervical lymph node metastasis.

CONCLUSIONS

Genetic evaluation showed ETV6/NTRK3 fusion but no BRAF mutations or RET/PTC rearrangements. RET/PTC rearrangement and BRAF mutations often contribute to the pathogenesis of PTC; however, rearrangements of NTRK genes are relatively rare in pediatric PTC. Although NTRK rearrangement has been shown to often present unique pathological types and infiltrative architectures in the western population, such findings were not observed in this patient. Thus, the present case of classic PTC with ETV6/NTRK3 rearrangement highlights the disparate collection of clinic-pathological features compared to the trend in the western population. We therefore emphasize the need to further accumulate clinical as well as genetic data in pediatric PTCs.

Optimizing treatment for children and adolescents with papillary thyroid carcinoma in post-Chernobyl exposed region: The roles of lymph node dissections in the central and lateral neck compartments

There is lack of data to predict lymph node metastases in pediatric thyroid cancer. The aims are to study (1) the factors affecting the lymph node metastases in children and adolescence with papillary thyroid carcinoma in region exposed to radiation and (2) to evaluate the predictive significance of these factors for lateral compartment lymphadenectomy. Five hundred and nine patients with papillary thyroid carcinoma underwent total thyroidectomy and lymph nodes resection (central and lateral compartments of the neck) surgery during the period of 1991-2010 in Belarus were recruited. The factors related to lymph node metastases were studied in these patients. In the patients with papillary thyroid carcinoma, increase number of cancer-positive lymph nodes in the central neck compartment were associated with a risk to develop lateral nodal disease as well as bilateral nodal disease. Futhermore, positive lateral compartment nodal metastases are associated with age and gender of the patients, tumour size, minimal extra-thyroidal extension, solid architectonic, extensive desmoplasia in carcinoma, presence of psammoma bodies, extensive involvement of the thyroid and metastatic ratio index revealed after examination of the central cervical chain lymph nodes. The presence of nodal disease, degree of lymph node involvement and the distribution of lymph node metastases significantly increase the recurrence rates of patients with papillary thyroid carcinoma. To conclude, the lymph nodes metastases in young patients with papillary thyroid carcinoma in post-Chernobyl exposed region are common and the pattern could be predicted by many clinical and pathological factors.

Prevalence and Significance of Thyroglobulin Antibodies in Pediatric Thyroid Cancer

CONTEXT

Circulating thyroglobulin antibodies (TgAb) can confound measurement of serum thyroglobulin and impair thyroid cancer surveillance. Few data exist on the significance of TgAb in pediatric thyroid cancer.

OBJECTIVE

To describe the prevalence, natural history, and clinical significance of TgAb in children with thyroid cancer.

DESIGN

Retrospective cohort study.

SETTING

Single academic pediatric center.

PATIENTS

Seventy-three consecutive children (≤18 years) with nonmedullary thyroid cancer who had serum TgAb measured within 6 months after diagnosis.

MAIN OUTCOME MEASURES

Prevalence and natural history of TgAb; association of TgAb status and resolution with patient and disease characteristics.

RESULTS

TgAb were detected in 41% of subjects (30 of 73) and were associated with lymph node metastasis (83% vs 53%, P = 0.01) but not distant metastasis. In patients with TgAb, resolution occurred in 44% (11 of 25) over a median follow-up of 3.8 years. Median time to clear TgAb was 10.7 months, and 10 of 11 patients who cleared (91%) did so within 2 years. Resolution of TgAb was associated with lower initial TgAb level (median 4.5 vs 76 normalized units, P = 0.003). TgAb positivity at diagnosis was not independently associated with persistent or recurrent disease (odds ratio 3.20, 95% confidence interval 0.95 to 10.80, P = 0.06).

CONCLUSIONS

TgAb are common at diagnosis in children with thyroid cancer but resolve in nearly half of patients within 1 to 2 years. TgAb are associated with the presence of lymph node metastasis at diagnosis, but the long-term prognostic significance remains to be determined.

Comparison of differentiated thyroid cancer in children and adolescents (≤20 years) with young adults

CONTEXT

Age is a major prognostic factor in differentiated thyroid cancer (DTC). It is not clear if paediatric DTC has a different histopathological profile and outcome than DTC in adult patients <45 years of age.

OBJECTIVE

To assess whether DTC in children and adolescents differs from young age group by comparing paediatric DTC (age ≤ 20) with DTC in patients >20 to <45 years of age.

PATIENTS AND METHODS

We studied all cases of paediatric DTC seen during the period 1998-2011. We compared this group with a large sample of 213 consecutive adult patients in the age group >20 to <45 years seen during the period 1998-1999 in terms of their pathological features, extent of the disease and long-term outcome. Both groups were managed by the same team at a single institution.

RESULTS

A total of 310 DTC were studied including 97 paediatric patients [median age 17 years (range, 8-20)] and 213 young adult patients [median age 33 years (range, 20·5-44·9)]. There was no difference in gender distribution, tumour subtypes, size and tumour multifocality, but there was a significantly higher rate of extrathyroidal extension [40/75 (53·3%) vs 81/213 (38·0%), P = 0·03], lymph node [57/73 (78%) vs 102/183 (55·7%), P < 0·0001] and distant metastases [16/97 (16·5%) vs 8/213 (3·8%), P < 0·0001] in the paediatric than the adult groups. Kaplan-Meier analysis showed a higher risk of persistent/recurrent disease in the paediatric group than adults (log-rank test 0·03). However, there was no mortality secondary to DTC in both groups.

CONCLUSION

Paediatric DTC is distinct from DTC in the young adults (age >20 to <45 years). It is characterized by a higher rate of extrathyroidal extension, lymph node and distant metastases and a higher risk of persistent/recurrent DTC.

Uncommon TERT Promoter Mutations in Pediatric Thyroid Cancer

PURPOSE

The aim of this study was to determine the rate and significance of TERT promoter mutations that have been recently described in adult thyroid cancer (TC) but not yet in the uncommonly occurring pediatric TC. Furthermore, the role of the BRAF(V600E) mutation in the clinical outcome of pediatric TC is unknown.

METHOD

The study included 55 pediatric (median age 16 years, range 9-18 years; 46 females) and 210 adult TC patients (median age 40 years, range 20-75 years; 155 females) seen during the same time period. DNA was isolated from TC tissues and subjected to direct sequencing. Genetic-clinicopathological correlations were analyzed.

RESULTS

Only one case of pediatric TC was found to harbor the C228T TERT promoter mutation (1.8%). The C250T mutation was not detected in any of the 55 pediatric TC. In contrast, there was a significantly higher rate of TERT promoter mutations in the adult patients (15.7%, 33/210) compared with the pediatric patients (p = 0.003). In addition, persistent/recurrent TC was seen in 8/12 (66.7%) pediatric patients harboring the BRAF(V600E) mutation versus 14/41 (34.1%) patients harboring the wild type BRAF (p = 0.05), and when only conventional papillary TC was examined, in 7/9 (77.8%) cases harboring BRAF(V600E) mutation versus 11/33 (33.3%) cases harboring wild type BRAF (p = 0.025).

CONCLUSIONS

This is the first study on TERT promoter mutations in pediatric TC, which revealed an exceedingly low prevalence, suggesting a limited role of these mutations in pediatric TC. This study also for the first time demonstrates an association of the BRAF(V600E) mutation with TC recurrence in pediatric patients.

Identification of epistatic interactions through genome-wide association studies in sporadic medullary and juvenile papillary thyroid carcinomas

Background

The molecular mechanisms leading to sporadic medullary thyroid carcinoma (sMTC) and juvenile papillary thyroid carcinoma (PTC), two rare tumours of the thyroid gland, remain poorly understood. Genetic studies on thyroid carcinomas have been conducted, although just a few loci have been systematically associated. Given the difficulties to obtain single-loci associations, this work expands its scope to the study of epistatic interactions that could help to understand the genetic architecture of complex diseases and explain new heritable components of genetic risk.

Methods

We carried out the first screening for epistasis by Multifactor-Dimensionality Reduction (MDR) in genome-wide association study (GWAS) on sMTC and juvenile PTC, to identify the potential simultaneous involvement of pairs of variants in the disease.

Results

We have identified two significant epistatic gene interactions in sMTC (CHFR-AC016582.2 and C8orf37-RNU1-55P) and three in juvenile PTC (RP11-648k4.2-DIO1, RP11-648k4.2-DMGDH and RP11-648k4.2-LOXL1). Interestingly, each interacting gene pair included a non-coding RNA, providing thus support to the relevance that these elements are increasingly gaining to explain carcinoma development and progression.

Conclusions

Overall, this study contributes to the understanding of the genetic basis of thyroid carcinoma susceptibility in two different case scenarios such as sMTC and juvenile PTC.

Electronic supplementary material

The online version of this article (doi:10.1186/s12920-015-0160-7) contains supplementary material, which is available to authorized users.

Trends in Thyroid Cancer Incidence in Korean Children (1999-2012) Based on Palpation and Nonpalpation Detection Methods

BACKGROUND

The incidence of childhood thyroid cancer is increasing in several populations; however, contributing factors have not been adequately discussed.

OBJECTIVES

Our aim was to identify trends of childhood thyroid cancer based on the Korea Central Cancer Registry (KCCR) database and to elucidate changes in detection methods of cancers using a single-center database.

METHODS

Data from the KCCR and Statistics Korea between 1999 and 2012 were used to calculate the crude incidence of thyroid cancer in children. To analyze detection methods for cancers, pediatric patients (aged 0-19 years, n = 126) who underwent thyroid surgery for thyroid cancers at our institution were identified. Subjects were divided into two groups by detection method: (1) palpation group and (2) screening group.

RESULTS

The crude incidence of childhood thyroid cancer increased from 0.5 per 100,000 in 1999 to 1.7 in 2012. The proportion of thyroid cancer among total cancers also increased from 4.4% in 1999 to 10.6% in 2012. Among 126 children from our institution, 91 cases (72%) were identified as palpable neck masses, and the remainder were discovered during imaging studies. The numbers in both groups gradually increased during the study period.

CONCLUSIONS

The incidence of childhood thyroid cancer has steadily increased in Korea. Regarding the detection methods of cancers, most tumors are detected by palpation rather than screening, although the rate of masses identified during screening has increased.

Review of clinical and pathological features of 93 cases of well-differentiated thyroid carcinoma in pediatric age at the Lisbon Centre of the Portuguese Institute of Oncology between 1964 and 2006

INTRODUCTION

Thyroid carcinoma is the most common endocrine malignancy. In childhood, thyroid carcinoma usually behaves aggressively and relapses frequently. Nevertheless, it has a favorable prognosis. Our aim is to present our experience with pediatric well-differentiated thyroid carcinoma (WDTC) treated at the Portuguese Institute of Oncology in Lisbon (L-PIO), between 1964 and 2006.

METHODS

Review of clinical files of WDTC in≤18-year-old patients selected from the databases of the Endocrinology Service of L-PIO and the South Portugal Regional Cancer Registry (SPCR).

RESULTS

93 cases of WDTC were found. Of these, 70 (75.3%) were girls. The median age was 15 years old (range 5-18) with a median follow-up time of 15.1 years (range 0.2-47.8). The most common histological diagnosis was papillary carcinoma of the classical variant (n=60, 64.5%). Initial staging showed locoregional dissemination in 27 (29.0%) patients and distant metastasis in 16 (17.2%) patients. Median age was lower in patients with distant disease than in patients with locoregional disease or with disease confined to the thyroid (P=0.007). After the initial treatment, 44 (47.3%) patients were in remission and 46 (49.5%) had persistent disease (lost follow-up in 3). Of the disease-free patients after initial treatment, 11 (25.0%) relapsed later. At the last observation, most patients (n=63, 67.7%) showed no evidence of disease.

CONCLUSION

Our study demonstrates that children with distant metastatic disease are younger than children with a less aggressive disease. However, in both groups the response to treatment is favorable and the prognosis is usually excellent.

Insights into genetic and epigenetic determinants with impact on vitamin d signaling and cancer association studies: the case of thyroid cancer

Vitamin D is a key regulator of calcium metabolism and has been implicated as a cancer preventive agent. However, clinical studies have revealed conflicting results on its cancer preventive properties, attributed in part to multiple metabolic and regulatory factors susceptible to affect individual responses to exogenous vitamin D. Vitamin D is obtained from dietary sources and sun exposure, which depends on numerous parameters such as skin type, latitude, and lifestyle factors. Focusing on thyroid cancer (TC), we document that genetic and epigenetic determinants can greatly impact individual response to vitamin D and may outweigh the classical clinical correlative studies that focus on sun exposure/dietary intake factors. In particular, genetic determinants innate to host intrinsic metabolic pathways such as highly polymorphic cytochromes P450s responsible for the metabolic activation of vitamin D are expressed in many organs, including the thyroid gland and can impact vitamin D interaction with its nuclear receptor (VDR) in thyroid tissue. Moreover, downstream regulatory pathways in vitamin D signaling as well as VDR are also subject to wide genetic variability among human populations as shown by genome-wide studies. These genetic variations in multiple components of vitamin D pathways are critical determinants for the revaluation of the potential preventive and anticancer properties of vitamin D in TC.

Recurrent thyroid papillary carcinoma in children under ten years old: report of two cases and literature review

Papillary thyroid carcinoma (PTC) in children under ten years old is very rare. To date, 18 cases of PTC in children under ten years old (including our two cases) have been reported in Korea. Here, we describe two cases of recurrent PTC with follicular variant and conventional type in an 8-year-old boy and a 7-year-old boy, respectively, and discuss clinicopathologic and molecular characteristics that differ in pediatric patients from adults.

Tall Cell Variant of Papillary Thyroid Carcinoma in Children

Papillary thyroid carcinoma (PTC), tall cell (TC) variant, is exceptional in children. In adults it represents about 20% of PTCs, featuring a high-risk neoplasm, with a 4-fold risk of relapse and a 20-fold relapse-related risk of death. Out of 42 cases of pediatric PTCs, we found 3 cases of PTC-TC (7%) with clinical data at onset and follow-up up to June 2014. They were 3 females aged 13, 15, and 15 years. Local extrathyroid extension was present in 2 cases. Neither nodal nor distant metastases were found. Two patients underwent hemithyroidectomy and 1 patient a total thyroidectomy, followed in all cases by life-long suppressive hormonal therapy. On follow-up, the patients were alive and well after 29, 24, and 29 years, respectively. The rarity of PTC-TC in children was confirmed. The behavior was indolent after a median follow-up of about 29 years, following treatment with hemithyroidectomy in 2 cases and controlled by suppressive hormonal therapy. The results of this series, albeit small, suggest that TC morphology in PTC does not carry the same negative prognostic significance in children as it does in adults. A conservative approach should therefore be considered for these ‘pediatric type’ cases of this tumor type.

Initial presentation and late results of treatment of post-Chernobyl papillary thyroid carcinoma in children and adolescents of Belarus

BACKGROUND

The aim of this population-based study was to evaluate the clinical and pathological characteristics and outcome of papillary thyroid carcinoma (PTC) that have arisen in the Belarusian childhood population exposed to the radioactive fallout from the Chernobyl accident within a long-term period.

PATIENTS AND METHODS

The long-term treatment results were investigated in 1078 children and adolescents (<19 years old) with PTC who were surgically treated during the years 1990 through 2005.

RESULTS

Patients had high rates of metastatic PTC at presentation, with 73.8% of cases having lymph node involvement and 11.1% having distant spread. The most influential factor for lymph node metastases at initial treatment was lymphatic vessel invasion (P < .0001) and for distant metastases, lateral lymph node involvement (P < .0001). The overall survival was 96.9% ± 0.9% with a median follow-up of 16.21 years, and 20-year event-free survival and relapse-free survival were 87.8% ± 1.6% and 92.3% ± 0.9%, respectively. Patients had significantly lower probability of both loco-regional (P < .001) and distant relapses (P = .005) after total thyroidectomy (TT) and radioactive iodine therapy (RAI). For loco-regional relapses after TT, only RAI influenced the prognosis significantly (P < .001). For distant relapses after TT, the refusal to treat with RAI (hazard ratio [HR] = 9.26), vascular invasion (HR = 8.68), and age at presentation (HR = 6.13) were significant risk factors. For loco-regional relapses after non-TT, the principal risk factors were age less than 15 years old at presentation (HR = 5.34) and multifocal growth of tumor (HR = 5.19). For distant relapses after non-TT, the lateral neck metastases were the only unfavorable factor (HR = 9.26).

CONCLUSION

The outcome of PTC both in children and in adolescents exposed to the post-Chernobyl radioiodine fallout was rather favorable. TT with RAI is recommended for minimizing loco-regional or distant relapses.

Aggressive variants of follicular cell-derived thyroid carcinomas: a cytopathologist's perspective

Follicular cell-derived carcinomas of the thyroid gland comprise a heterogeneous group of malignant neoplasms of the thyroid gland with varied histologic appearance and molecular profiles. In most patients, these tumors represent relatively indolent neoplasms; however, certain subtypes/variants behave in an aggressive manner, and the recognition of this subset of tumors is essential because of their variable response to therapy and significant morbidity and mortality. Fine-needle aspiration is considered an essential tool for the diagnosis of suspicious thyroid nodules. In this review, the authors discuss the clinical, histologic, and molecular findings and the prognostic implications of aggressive thyroid neoplasms with emphasis on the characteristic cytomorphologic features on fine-needle aspiration smears.

Genetic alterations in thyroid tumors from patients irradiated in childhood for tinea capitis treatment

OBJECTIVE

Exposure to ionizing radiation at young age is the strongest risk factor for the occurrence of papillary thyroid carcinoma (PTC). RET/PTC rearrangements are the most frequent genetic alterations associated with radiation-induced PTC, whereas BRAF and RAS mutations and PAX8-PPARG rearrangement have been associated with sporadic PTC. We decided to search for such genetic alterations in PTCs of patients subjected in childhood to scalp irradiation.

DESIGN

We studied 67 thyroid tumors from 49 individuals irradiated in childhood for tinea capitis scalp epilation: 36 malignant (12 cases of conventional PTC (cPTC), two cPTC metastases, 20 cases of follicular variant PTC (FVPTC), one oncocytic variant of PTC and one follicular carcinoma) and 31 follicular thyroid adenomas.

METHODS

The lesions were screened for the BRAF(V600E) and NRAS mutations and for RET/PTC and PAX8-PPARG rearrangements.

RESULTS

BRAF(V600E) mutation was detected in seven of 14 (50%) cPTC and two of 20 FVPTC (10%) (P=0.019). NRAS mutation was present in one case of FVPTC (5%). RET/PTC1 rearrangement was found, by RT-PCR, in one of 17 cases (5.9%) and by fluorescence in situ hybridization in two of six cases (33%). PAX8-PPARG rearrangement was not detected in any carcinoma. None of the follicular adenomas presented any of the aforementioned genetic alterations.

CONCLUSIONS

The prevalence of BRAF(V600E) mutation in our series is the highest reported in series of PTCs arising in radiation-exposed individuals. The prevalence of RET/PTC1 rearrangement fits with the values recently described in a similar setting.

Aggressive variants of follicular cell derived thyroid carcinoma; the so called 'real thyroid carcinomas'

The pathological diagnoses and classification schemes for thyroid carcinoma have changed over the past 20 years and continue to do so. New entities have been described and molecular analyses have suggested better characterisation and grouping of certain tumours. Because some of the lesions have been named differently by different authors, clinicians and patients may be confused as to what a specific patient's lesion represents. In this review, we discuss the thyroid tumours of follicular origin which are clinically unusual but important to recognise as their behaviour may be aggressive, they may not respond to radioiodine treatment and they may cause significant mortality. This paper describes these important but rare lesions, their pathological features, important clinicopathological correlations, molecular correlates and prognostic implications.

Adequacy of pathology reports of specimens from patients with differentiated thyroid cancer

This study aims to investigate the adequacy of pathology reports of specimens from patients with differentiated thyroid cancer (DTC) operated in our institution. Retrospective analysis of the pathology reports of all patients diagnosed with DTC in our area, from 1 January 2006 through 30 June 2011, was done. Sixty-eight patients were diagnosed with DTC. All reports were descriptive. In all the reports, but one, one or more core data items (according to the Royal College of Pathologists) were missing. Information about 1 and 2 items was lacking in 7.4 and 42.6 % of the reports, respectively. The rest were missing three or more data. Lymphovascular invasion, histology subtype, and completeness of excision were, in this order, the three most frequently omitted data. Sometimes, the information in question was not explicitly expressed but could be extrapolated from the data available. The pathology reports of DTC specimens frequently miss some of the information considered necessary to provide a comprehensive patient care.