The genomic and evolutionary landscapes of anaplastic thyroid carcinoma

Anaplastic thyroid carcinoma is arguably the most lethal human malignancy. It often co-occurs with differentiated thyroid cancers, yet the molecular origins of its aggressivity are unknown. We sequenced tumor DNA from 329 regions of thyroid cancer, including 213 from patients with primary anaplastic thyroid carcinomas. We also whole genome sequenced 9 patients using multi-region sequencing of both differentiated and anaplastic thyroid cancer components. Using these data, we demonstrate thatanaplastic thyroid carcinomas have a higher burden of mutations than other thyroid cancers, with distinct mutational signatures and molecular subtypes. Further, different cancer driver genes are mutated in anaplastic and differentiated thyroid carcinomas, even those arising in a single patient. Finally, we unambiguously demonstrate that anaplastic thyroid carcinomas share a genomic origin with co-occurring differentiated carcinomas and emerge from a common malignant field through acquisition of characteristic clonal driver mutations.

Management of Medullary Thyroid Cancer: Patterns of Recurrence and Outcomes of Reoperative Surgery

BACKGROUND

There remains uncertainty regarding the optimal extent of initial surgery and management of recurrent disease in medullary thyroid cancer (MTC). We aim to describe the patterns of disease recurrence and outcomes of the reoperative surgery in a cohort of consecutively treated patients at a specialized tertiary referral center.

PATIENTS AND METHODS

A retrospective cohort study of 235 surgically treated patients with MTC at a tertiary referral center was performed using prospectively collected data.

RESULTS

In the study period 1986-2022, 235 patients underwent surgery for MTC. Of these, 45 (19%) patients had reoperative surgery for cervical nodal recurrence at a median (range) 2.1 (0.3-16) years following the index procedure. After a median follow-up of 4 years, 38 (84%) patients remain free of structural cervical recurrence, although 15 (33%) underwent 2 or more reoperative procedures. No long-term complications occurred after reoperative surgery. Local cervical recurrence was independently predicted by pathologically involved nodal status (OR 5.10, P = .01) and failure to achieve biochemical cure (OR 5.0, P = .009). Local recurrence did not adversely affect overall survival and was not associated with distant recurrence (HR 0.93, P = .83). Overall survival was independently predicted by high pathological grade (HR 10.0, P = .002) and the presence of metastatic disease at presentation (HR 8.27, P = 0018).

CONCLUSION

Loco-regional recurrence in MTC does not impact overall survival, or the development of metastatic disease, demonstrating the safety of the staged approach to the clinically node-negative lateral neck. When recurrent disease is technically resectable, reoperative surgery can be undertaken with minimal morbidity in a specialized center and facilitates structural disease control.

A Detailed Histologic and Molecular Assessment of the Diffuse Sclerosing Variant of Papillary Thyroid Carcinoma

Diffuse sclerosing variant papillary thyroid carcinoma (DS-PTC) is characterized clinically by a predilection for children and young adults, bulky neck nodes, and pulmonary metastases. Previous studies have suggested infrequent BRAFV600E mutation but common RET gene rearrangements. Using strict criteria, we studied 43 DS-PTCs (1.9% of unselected PTCs in our unit). Seventy-nine percent harbored pathogenic gene rearrangements involving RET, NTRK3, NTRK1, ALK, or BRAF; with the remainder driven by BRAFV600E mutations. All 10 pediatric cases were all gene rearranged (P = .02). Compared with BRAFV600E-mutated tumors, gene rearrangement was characterized by psammoma bodies involving the entire lobe (P = .038), follicular predominant or mixed follicular architecture (P = .003), pulmonary metastases (24% vs none, P = .04), and absent classical, so-called "BRAF-like" atypia (P = .014). There was no correlation between the presence of gene rearrangement and recurrence-free survival. Features associated with persistent/recurrent disease included pediatric population (P = .030), gene-rearranged tumors (P = .020), microscopic extrathyroidal extension (P = .009), metastases at presentation (P = .007), and stage II disease (P = .015). We conclude that DS-PTC represents 1.9% of papillary thyroid carcinomas and that actionable gene rearrangements are extremely common in DS-PTC. DS-PTC can be divided into 2 distinct molecular subtypes and all BRAFV600E-negative tumors (1.5% of papillary thyroid carcinomas) are driven by potentially actionable oncogenic fusions.

A Critical Assessment of Diagnostic Criteria for the Tall Cell Subtype of Papillary Thyroid Carcinoma-How Much? How Tall? And When Is It Relevant?

Tall cell papillary thyroid carcinoma (TC-PTC) is considered adverse histology. However, previous studies are confounded by inconsistent criteria and strong associations with other adverse features. It is therefore still unclear if TC-PTC represents an independent prognostic factor in multivariate analysis and, if it does, what criteria should be employed for the diagnosis. We retrospectively reviewed 487 PTCs from our institution (where we have historically avoided the prospective diagnosis of TC-PTC) for both the height of tall cells (that is if the cells were two, or three, times as tall as wide) and the percentage of tall cells. On univariate analysis, there was significantly better disease free survival (DFS) in PTCs with no significant tall cell component (< 30%) compared to PTCs with cells two times tall as wide (p = 0.005). The proportion of tall cells (30-50% and > 50%) was significantly associated with DFS (p = 0.012). In a multivariate model including age, size, vascular space invasion, and lymph node metastasis, the current WHO tall cell criteria, met by 7.8% of PTCs, lacked statistical significance for DFS (p = 0.519). However, in the subset of tumours otherwise similar to the American Thyroid Association (ATA) guidelines low-risk category, WHO TC-PTC demonstrated a highly significant reduction in DFS (p = 0.004). In contrast, in intermediate to high-risk tumours, TC-PTC by WHO criteria lacked statistical significance (p = 0.384). We conclude that it may be simplistic to think of tall cell features as being present or absent, as both the height of the cells (two times versus three times) and the percentage of cells that are tall have different clinical significances in different contexts. Most importantly, the primary clinical significance of TC-PTC is restricted to PTCs that are otherwise low risk by ATA guidelines.

The Presence of Typical "BRAFV600E-Like" Atypia in Papillary Thyroid Carcinoma is Highly Specific for the Presence of the BRAFV600E Mutation

Papillary thyroid carcinomas (PTCs) are driven by a variety of molecular abnormalities including BRAF, RAS, ALK, RET, and NTRK alterations. PTCs driven by the BRAFV600E mutation, or tumours which demonstrate a similar gene expression profile to PTCs driven by this mutation, have been reported to demonstrate specific morphological features sometimes termed "BRAFV600E-like" atypia. BRAFV600E-like atypia is characterised by a well-developed papillary architecture, infiltrative growth, marked nuclear clearing, prominent intranuclear pseudoinclusions, abundant eosinophilic cytoplasm, and scattered psammoma bodies. We sought to investigate the sensitivity and specificity of these morphological features for the presence of BRAFV600E mutation in PTCs as determined by mutation specific immunohistochemistry. An unselected cohort of 495 PTCs was reviewed by a single pathologist and categorised into three groups: typical BRAFV600E-like atypia (145 cases, 29%), possible BRAFV600E-like atypia (166 cases, 33%) and little/no BRAFV600E-like atypia (184 cases, 37%). The specificity and sensitivity of typical BRAFV600E-like atypia for the BRAFV600E mutation was 97.2% and 44.3%, respectively. When typical and possible BRAFV600E-like atypia were analysed together, the specificity was 70.6% and the sensitivity was 81.7%. In the morphologically little/no BRAFV600E-like atypia group, 58 cases (31.5%) had a BRAFV600E mutation. We conclude that typical BRAFV600E-like atypia is highly specific for the presence of the BRAFV600E mutation; however, the absence of BRAFV600E-like atypia does not exclude this mutation.

Beware the recurrent 'benign' multinodular goitre

BACKGROUND

The diagnosis of follicular carcinoma is often difficult to make on pathological analysis, as the histological distinction from follicular adenoma rests solely on the presence of capsular or vascular invasion. Even on retrospective review of the histopathology after the disease biology has declared itself as malignant, the pathological diagnosis of malignancy may not be possible to make.

METHODS

We report three cases in which patients were initially diagnosed with benign follicular lesions, but re-presented with locally recurrent disease and a subsequent malignant disease course.

RESULTS

We describe a rare entity of follicular thyroid carcinoma that demonstrates a locally recurrent and eventually metastatic disease phenotype, despite persistently benign pathological findings.

CONCLUSION

We highlight that if local recurrence occurs in discrete anatomical tissue planes, or in the thyroid bed following open total thyroidectomy for 'benign multinodular goitre', the possibility of this rare presentation of follicular thyroid carcinoma should be considered.

Temperature sensing by the calcium-sensing receptor

Whether GPCRs support the sensing of temperature as well as other chemical and physical modalities is not well understood. Introduction: Extracellular Ca²⁺ concentration (Ca²⁺ _o) modulates core body temperature and the firing rates of temperature-sensitive CNS neurons, and hypocalcemia provokes childhood seizures. However, it is not known whether these phenomena are mediated by Ca²⁺ _o-sensing GPCRs, including the calcium-sensing receptor (CaSR). In favor of the hypothesis, CaSRs are expressed in hypothalamic regions that support core temperature regulation, and autosomal dominant hypocalcemia, due to CaSR activating mutations, is associated with childhood seizures. Methods: Herein, we tested whether CaSR-dependent signaling is temperature sensitive using an established model system, CaSR-expressing HEK-293 cells. Results: We found that the frequency of Ca²⁺ _o-induced Ca²⁺ _i oscillations but not the integrated response was linearly dependent on temperature in a pathophysiologically relevant range. Chimeric receptor analysis showed that the receptor's C-terminus is required for temperature-dependent modulation and experiments with the PKC inhibitor GF109203X and CaSR mutants T888A and T888M, which eliminate a key phosphorylation site, demonstrated the importance of repetitive phosphorylation and dephosphorylation. Discussion and Conclusion: CaSRs mediate temperature-sensing and the mechanism, dependent upon repetitive phosphorylation and dephosphorylation, suggests that GPCRs more generally contribute to temperature-sensing.

Focused parathyroidectomy without intraoperative parathyroid hormone measurement in primary hyperparathyroidism: Still a valid approach?

BACKGROUND

Concern regarding suboptimal cure rates has led to some endocrine surgery units abandoning focused parathyroidectomy for primary hyperparathyroidism in favor of open bilateral neck exploration or making intraoperative parathyroid hormone estimation mandatory in focused parathyroidectomy. This study explores whether focused parathyroidectomy for radiologically localized primary hyperparathyroidism without intraoperative parathyroid hormone is still a valid approach.

METHODS

Retrospective review of a tertiary referral endocrine surgery unit database. All parathyroidectomies for primary hyperparathyroidism over 6 years (2013-2019) were included. Lithium-induced hyperparathyroidism, reoperations, familial disease, and concurrent thyroid surgery were excluded. Characteristics and outcomes for focused parathyroidectomy and open bilateral neck exploration were compared by intention-to-treat and treatment delivered. Persistence and recurrence, conversions and complications were analyzed as endpoints.

RESULTS

A total of 2,828 parathyroidectomies were performed and 2,421 analyzed. By intention to treat there were 1,409 focused parathyroidectomies and 1,012 open bilateral neck explorations. Focused parathyroidectomy patients were younger: 63 vs 66 years (P < .01); however, gender (77%, 79% female), preoperative peak serum calcium (2.72, 2.70 mmol/L [P = .23]), and serum parathyroid hormone (11.5, 11.0 pmol/L [P = .52]) did not differ. In total, 229 (16.3%) focused parathyroidectomies were converted to open bilateral neck exploration. Multiple gland disease was confirmed in 54.5% of converted patients. Median follow-up was 41 months (3-60 months). Persistence or recurrence requiring reoperation totaled 2.2% and did not differ between focused parathyroidectomy and open bilateral neck exploration in either intention to treat or final treatment analyses. Complications occurred in 1.2% of focused parathyroidectomy and 3.2% open bilateral neck exploration (P < .01).

CONCLUSIONS

In experienced hands and with a ready-selective approach to conversion, focused parathyroidectomy based on concordant imaging and without intraoperative parathyroid hormone may deliver equivalent cure rates to open bilateral neck exploration with significantly fewer complications. Focused parathyroidectomy without intraoperative parathyroid hormone should therefore be maintained in the endocrine surgeon's armamentarium.

The Significance of Histologically "Large Normal" Parathyroid Glands in Primary Hyperparathyroidism

INTRODUCTION

We investigated outcomes in a cohort of patients with a biochemical diagnosis of primary hyperparathyroidism (pHPT) undergoing surgery for asymptomatic disease or target organ damage, where a focussed or four-gland operation was undertaken and the histopathology only reported a "large normal" parathyroid gland (LNP).

METHODS AND MATERIALS

Patients subjected to a parathyroidectomy for pHPT between 2012 and 2018 with a pathology of LNP were included. Patients with fat depletion or additional histological features of adenoma or hyperplasia in any of the resected glands were excluded. A control group was formed from 50 consecutive patients with the histological finding of adenoma or hyperplasia during the same study period. The primary outcome was biochemical normalisation of pHPT at 1-2 weeks and after 6 months post-operatively.

RESULTS

Forty-eight LNP patients (2% of all parathyroidectomies) were included in the study group with 50 matched controls. LNP patients had a lower biochemical cure rate (81% vs. 98% P < 0.05) and a higher risk of recurrence (10% vs. 0%, P = 0.06). LNP patients had a milder form of pHPT (Ca²⁺ 2.63 vs. 2.68 P < 0.05) with a smaller PTH and Ca²⁺ drop post-operatively. For LNP patients with failure, a definite additional cause of pHPT was found in only two patients.

CONCLUSION

This study highlights a controversial area in pHPT and reports LNP as a cause of pHPT. The biochemical analysis of this LNP group supports a benefit in resection in the setting of pHPT, although the risk of failure (persistence/recurrence) is higher than those with adenoma or hyperplasia. Stricter post-operative follow-up of LNP patients should be considered.

Sonographic Volumetric Assessment Is a More Accurate Measure Than Maximum Diameter Alone in Papillary Thyroid Cancer

Background

Tumor size is an important prognostic factor in papillary thyroid cancer (PTC). Management guidelines, staging systems, and pathological definitions use maximum diameter (Dmax) as a surrogate marker of tumor size. However, PTC nodules are three-dimensional (3D) structures, with behavior reflective of tumor cell count, which is directly proportional to volume. We explored the relationship between sonographically determined Dmax, volume, and lymph node status (LNS) in a cohort of patients with PTC.

Methods

All patients treated for PTC between 2003 and 2015 in our institution who had sonographic 3D nodule measurements available were evaluated. We examined the relationship between diameter, volume, and LNS.

Results

A total of 159 nodules in 153 patients met the inclusion criteria. Mean nodule dimensions were 2.4 × 1.9 × 1.5 cm, giving “ideal” nodule dimensions of y × 0.78y × 0.62y, where y is the Dmax. Observed volumes differed from predicted nodule volumes by an average of 26.2%. For PTC ≤2 cm, the coefficient of variation was 26.7%. Dmax did not correlate with the presence of lymph node metastases (Pearson coefficient 0.08), whereas volume very weakly correlated with LNS (Pearson coefficient 0.22). However, both Dmax and volume correlated very strongly with the number of nodal metastases (Pearson coefficients 0.93 and 0.89, respectively).

Conclusions

PTC nodules demonstrated significant volume heterogeneity, rendering Dmax an inaccurate marker of true tumor size. Although there was little difference between Dmax and volume in predicting nodal status or nodal disease burden, we propose that a prospective, randomized trial might demonstrate a clear clinical advantage of 3D sonographic nodule measurement over Dmax alone.

Single nucleotide polymorphism 1623 A/G (rs180195) in the promoter of the Thyroglobulin gene is associated with autoimmune thyroid disease but not with thyroid ophthalmopathy

Background

Our studies over recent years have focused on some new ideas concerning the pathogenesis for the orbital reaction that characterizes Graves’ ophthalmopathy namely, that there are antigens expressed by thyroid tissue and orbital tissue where they are targeted by autoantibodies and/or sensitized T cells, leading to orbital inflammation. While this has been well studied for the thyroid stimulating hormone-receptor, the possible role of another major thyroid antigen, Thyroglobulin (TG), has been largely ignored.

Methods

We identified novel variant 1623 A/G single nucleotide polymorphism (SNP) (rs180195) in the promoter of TG gene associated with autoimmune thyroid disorders. We genotyped the TG SNPs rs2069566, rs2076739, rs121912646, rs121912647, rs121912648, rs121912649, rs121912650, rs137854433, rs137854434, and rs180195 by MassARRAY SNP analysis using iPLEX technology in a cohort of 529 patients with thyroid autoimmunity with and without ophthalmopathy, and controls.

Results

We showed that variant 1623 A/G SNP (rs180195) in the promoter of TG gene is a marker for thyroid autoimmunity, but not for ophthalmopathy. We showed that there was a significant difference in the distribution of the major allele (G) vs minor allele (A) in patients with Hashimoto’s thyroiditis (HT). In HT the wild-type (GG) genotype was less common. We showed that the genotypes homozygous AA and heterozygous GA rs180195 SNP in the promoter of TG gene were more closely associated with thyroid autoimmunity than the wild-type (GG) polymorphism, and are thus, markers of autoimmunity.

Conclusion

rs180195 SNP was previously identified by Stefan et al independently of us, who showed that this TG SNP predisposed to autoimmune thyroid diseases. However, this is the first study to explore the association between TG SNPs and HT. Our findings support the notion that the thyroid and orbital disorders are not part of the same disease, ie, “Graves’ disease” or “Hashimoto’s disease”, but separate autoimmune disorders.

Disease Progression in Papillary Thyroid Cancer with Biochemical Incomplete Response to Initial Therapy

BACKGROUND

Dynamic risk stratification is utilized in the follow-up of patients with papillary thyroid carcinoma (PTC). Analysis of outcomes after biochemical incomplete response (BIR) to initial therapy will allow better individualization of care.

METHODS

A total of 494 patients with PTC were followed prospectively. Immunohistochemistry (IHC) for BRAF^V600E mutation was completed on all surgical specimens. After exclusion of patients with inadequate data, 353 patients were stratified into four categories of response to initial therapy: excellent, biochemical incomplete, structural incomplete, or indeterminate. Patients with BIR, defined as elevated stimulated thyroglobulin >2 µg/L with negative imaging, were analysed for progression of disease. The primary outcome measure was development of structural recurrence.

RESULTS

Forty-nine of 353 (13.9%) patients had BIR. BRAF^V600E mutation was present in 32 of 49 (65.3%) with BIR. Progression to structural recurrence occurred in 8 of 49 (16.3%) with BIR, all of whom were positive for the BRAF^V600E mutation (p = 0.02). Nine patients (18%) with BIR remitted during follow-up to no evidence of disease (6 had additional RAI therapy). After mean follow-up of 35 months, 12 patients with BIR (24%) remained biochemically abnormal with no structural evidence of disease.

CONCLUSIONS

Patients with BIR following initial treatment for PTC have generally favorable outcomes. Positive IHC for BRAF^V600E identifies patients at risk of structural disease recurrence.

TERT promoter mutations are a major indicator of recurrence and death due to papillary thyroid carcinomas

CONTEXT

TERT promoter mutations have been associated with adverse prognosis in papillary thyroid carcinomas (PTCs).

OBJECTIVE

We investigated the association between TERT promoter mutations and survival from PTC.

DESIGN

Retrospective observational cohort study.

PATIENTS

Eighty consecutive patients with PTC who underwent surgery between 1990 and 2003.

MEASUREMENTS

TERT promoter was genotyped in DNA from 80 archival PTCs by Sanger sequencing. Median follow-up was 106 months (range 1-270). Outcomes analysis was stratified according to disease and overall survival status. For each parameter, relative risk (RR) adjusted for age at first surgery and gender was estimated. Both univariate and multivariate analyses were performed using logistic regression, Kaplan-Meier survival analysis and Cox regression models.

RESULTS

PTCs from 11 patients (14%) contained either C228T or C250T TERT promoter mutation. TERT mutations were significantly associated with adverse prognostic features such as older age (P = 0·002), male gender (P = 0·01) and Stage IV disease (P = 0·03). Four patients died from PTC during follow-up: 3 patients with TERT mutations (27%) and one without (1·5%). Disease-related mortality rate with or without TERT mutations was 33·7 vs 1·6 per 1000 patient-years respectively, that is 10 (95% CI = 1·0-104·1, P = 0·05) fold higher, after adjustment for age at first surgery and gender. The combination of TERT promoter mutation and BRAF(V) (600E) significantly increased disease-related death risk (P = 0·002). TERT mutations increased expression of a reporter gene in thyroid cells containing BRAF(V) (600E) .

CONCLUSIONS

TERT promoter mutations are a major indicator of death due to PTCs. Conversely, absence of TERT mutations portends better survival.

Incidence and Risk Factors for Occult Level 3 Lymph Node Metastases in Papillary Thyroid Cancer

BACKGROUND

Papillary thyroid cancer (PTC) frequently disseminates into cervical lymph nodes. Lateral node involvement is described in up to 50 % patients undergoing prophylactic lateral neck dissection. This study aimed to assess this finding and identify which factors predict for occult lateral node disease.

METHODS

Patients with fine needle aspiration-confirmed PTC (Bethesda V or VI), without evidence of cervical lymph node metastases, underwent a total thyroidectomy with prophylactic ipsilateral central and level 3 dissection. Level 3 nodes were removed by compartmental dissection or by sampling the sentinel nodes overlying the jugular vein, according to surgeon preference. Data were collected prospectively from January 2011 to August 2014. Statistical analysis was performed by SPSS software.

RESULTS

A total of 137 patients underwent total thyroidectomy with prophylactic ipsilateral central and level 3 dissection for PTC. The incidence of occult level 3 disease was 30 % (41/137 patients). A total of 48 % of patients (66/137) harbored occult central neck disease. A total of 80.5 % of patients with pN1b disease had macrometastases (≥2 mm), and 15 % exhibited skip metastases with central compartment sparing. In patients with pN1b disease, a median of 6 level 3 nodes were retrieved, with an average involved nodal ratio of 0.29. Multivariate regression demonstrated risk factors for occult lateral neck metastasis include tumor size (odds ratio 1.1), upper pole tumors (odds ratio 6.6), and vascular invasion (odds ratio 3.2) (p < 0.05).

CONCLUSIONS

PTC is associated with a significant incidence of occult central and lateral nodal metastases. In patients undergoing prophylactic central neck dissection, inclusion of level 3 dissection should be considered in patients with large upper lobe cancers.

Is there a role for an ultrasensitive thyroglobulin assay in patients with serum antithyroglobulin antibodies? A large (Australian) cohort study in differentiated thyroid cancer

OBJECTIVE

Serum thyroglobulin (Tg) is a marker of residual differentiated thyroid cancer (DTC) after total thyroidectomy; however, circulating antithyroglobulin antibodies (TgAb) may interfere with the immunoassay for Tg. Ultrasensitive assays may have a more significant role in detecting circulating Tg in the context of samples containing TgAb. The aim of this study was to evaluate the utility of ultrasensitive thyroglobulin (US-Tg) measurement compared to standard Tg measurement and to assess the influence of serum TgAb positivity on Tg detection in a large tertiary referral centre cohort in Australia.

DESIGN

All patients with DTC who had undergone total thyroidectomy were included in this retrospective, observational cohort study.

PATIENTS

Patients providing samples for the period of June 2006 until January 2014 were analysed. Three thousand two hundred and eight samples were measured at the same points in time, enabling serum Tg assays to be compared for the same TSH status (stimulated or suppressed).

MEASUREMENTS

The standard assay, the Siemens Immulite 2000 Tg assay, was compared to the serum ultrasensitive ELISA RSR^™ Tg. TgAb were simultaneously measured using Abbott Architect or Immulite 2000.

RESULTS

There were 3019 samples included in the final analysis for comparison of the standard and ultrasensitive assays along with TgAb status. The majority of samples were TgAb negative (87%), with 48% of TgAb-negative samples associated with an undetectable serum Tg, suggestive of disease-free status at the time of sampling. Of note, 26% (n = 104) of the TgAb-positive samples were positive for Tg on the ultrasensitive Tg assay, but negative on the immulite Tg assay, and 62·5% (n = 65) of these samples corresponded to DTC recurrence.

CONCLUSION

The US-Tg assay has greater clinical utility than the standard immulite Tg assay specifically in the scenario of antibody positivity, with a significant number of samples corresponding to clinically relevant recurrent or metastatic disease.

Papillary thyroid cancer in childhood: is parental screening helpful?

BACKGROUND

Familial non-medullary thyroid cancer (FNMTC) mandates family screening with ultrasound; however, the need for screening paediatric thyroid cancer with no family history has not been addressed.

METHODS

This study conducted a retrospective cohort study in a tertiary hospital. The study group is composed of patients ≤18 years undergoing surgery for papillary thyroid cancer (PTC) from 2008 to 2014.

RESULTS

During the study period, 15 paediatric patients had PTC. Only one patient had a prior family history of PTC involving two second-degree relatives. Of the 30 parents, four were lost to follow-up, with the remaining 26 undergoing screening thyroid ultrasound. Nodular thyroid disease was documented in eight ultrasounds performed. Subsequently, one has not undergone fine-needle biopsy, five were benign and two underwent surgical resection: one having a benign follicular adenoma and the other a papillary microcarcinoma with nodal micrometastasis.

CONCLUSIONS

Routine ultrasound screening of parents of children presenting with PTC and no family history do not demonstrate an increased incidence of FNMTC. Screening of affected families is likely to demonstrate the expected background incidence of nodular thyroid disease and incidental papillary microcarcinoma. As such, it is unlikely to be useful.

Focused image-guided parathyroidectomy in the current management of primary hyperparathyroidism

OBJECTIVE

Primary hyperparathyroidism (PHPT) in childhood and adolescence has been considered a different disease to that seen in adults, with predominantly familial aetiology mandating open exploration to exclude parathyroid hyperplasia in contrast to the adoption of focused image-guided parathyroidectomy (FP) in adults.

STUDY DESIGN

A retrospective cohort study in a tertiary referral hospital setting of all children and adolescents (<18 years) undergoing parathyroid surgery for PHPT. Data were obtained from a dedicated endocrine surgery database and hospital medical records.

RESULTS

Over the 35-year study period (1980-2014), there were 31 patients who underwent parathyroidectomy for PHPT. 3 patients were from known multiple endocrine neoplasia type 1 syndrome (MEN1) families, 3 had an isolated family history of PHPT and 25 were sporadic. In the sporadic group, 24 (96%) presented with symptomatic hypercalcaemia, affecting the gastrointestinal, musculoskeletal, genitourinary or neuropsychiatric systems. In the 25 patients with sporadic PHPT, nine (36%) had FP with a single adenoma removed with a 100% initial cure rate. Sixteen patients (64%) in the sporadic group had an open exploration: 14 had single gland disease while 2 patients required a second procedure to achieve a final cure rate of 100%. Of the three patients with MEN1, one was cured, one has persistent hyperparathyroidism after FP and the third has permanent hypoparathyroidism after open exploration.

CONCLUSIONS

The majority of children and adolescents with PHPT have symptomatic disease due to a single adenoma. They can therefore be managed in a similar fashion to their adult counterparts with preoperative localisation studies aiming to permit FP in a day case setting.

Novel single-nucleotide polymorphisms in the calsequestrin-1 gene are associated with Graves' ophthalmopathy and Hashimoto's thyroiditis

BACKGROUND

The eye disorder associated with Graves' disease, called Graves' ophthalmopathy (GO), greatly reduces the quality of life in affected patients. Expression of the calsequestrin (CASQ1) protein in thyroid tissue may be the trigger for the development of eye muscle damage in patients with GO. We determined the prevalence of rs74123279, rs3747673, and rs2275703 single-nucleotide polymorphism (SNPs) in patients with autoimmune thyroid disorders, GO, Graves' hyperthyroidism (GH), or Hashimoto's thyroiditis (HT) and control subjects with no personal or family history of autoimmune thyroid disorders. Furthermore, we measured the concentration of the CASQ1 protein in normal and Graves' thyroid tissue, correlating levels with parameters of the eye signs, CASQ1 antibody levels, and the CASQ1 gene polymorphism rs74123279 and rs2275703.

METHODS

High-quality genomic DNA was isolated from fresh blood samples, assayed for identification of rs74123279, rs3747673, and rs2275703 SNPs in CASQ1 gene by MassARRAY SNP analysis using iPLEX technology of SEQUENOM.

RESULTS

DNA samples from 300 patients and 106 control subjects (100 males, 306 females) with GO (n=74), GH (n=130), HT (n=96) and control subjects (n=106) were genotyped for the SNPs rs74123279, rs3747673 (n=405), and rs2275703 (n=407). The SNP rs74123279, rs3747673, and rs2275703 were identified as 1) common homozygous or wild type, 2) heterozygote, and 3) rare homozygous. Minor allele frequency for rs74123279, rs3747763, and rs2275703 were 21%, 40%, and 44%, respectively. Multiple comparisons of genotype frequency for rs74123279, rs3747763, and rs2275703 in the GO, GH, HT, and control groups showed P=0.06, 0.641, and 0.189, respectively. These results were substantiated by multiple comparison of alleles frequency for rs74123279, rs3838216, rs3747763, and rs2275703 in the GO, GH, HT, and control groups showed, P=0.36, 0.008, 0.66, and 0.05, respectively. Pairwise analysis of alleles frequency distribution in patients with GO showed significant probability for rs2275703, P=0.008.

CONCLUSION

Based on their evolutionary conservation and their significant prevalence, we suggest that CASQ1 gene SNPs rs74123279, rs3838216, and rs2275703 may be considered as genetic markers for GO.

Risk of malignancy for each Bethesda class in pediatric thyroid nodules

PURPOSE

The Bethesda classification for cytology is used to classify thyroid nodules into one of six categories, and for each category there is an implied cancer risk and also recommendation for management. Despite lack of data in children, the American thyroid association promotes the use of the same management guidelines as in adults. Our aim was to study the risk of malignancy for each Bethesda class in children with thyroid nodules.

METHODOLOGY

We included all patients ≤18years of age that had underwent a thyroid fine needle aspiration (FNA) at one of two centers between January 1998 and July 2013. FNA results were reclassified according to the Bethesda criteria. Histological, repeat cytological, radiological and clinical follow-up were recorded.

RESULTS

Fifty-six patients (66 nodules) underwent FNB. Mean age was 13.6 years. Numbers of nodules reported as BI-BVI were 7, 38, 11, 4, 3 and 3, respectively. Follow-up was achieved for 55 (83%) nodules. Twelve (18%) nodules were malignant by histology and revealed papillary (n=7), follicular (n=3) or insular thyroid cancer (n=2), The proportion of nodules with malignancy for BI-BVI was: 0%, 0%, 18%, 100%, 100% and 100%.

CONCLUSION

The rate of malignancy in thyroid nodules in children seems to be higher than reported in adults. The Bethesda criteria seem to accurately identify benign nodules, but other categories have a very high rate of malignancy and BIII nodules pose a particular challenge.

Mortality associated with primary hyperparathyroidism

561 patients with primary hyperparathyroidism were followed between 1961 and 1994. Relative survival was compared to that of the Australian population studied during the same time interval. Mortality was significantly greater in the hyperparathyroid population (P<0.001). Mortality was not greater in the patients with serum calcium levels >3.00 mmol/L compared to those with a serum calcium levels <3.00 mmol/L. 113 patients did not have parathyroid surgery. Their relative survival was not significantly different from those who had surgery but their mean serum calcium and parathyroid hormone (PTH) levels were significantly lower than those who had surgery. A re-analysis of the 453 patients followed between 1972 and 2011 was carried out and a 20-year survival analysis made of those diagnosed between 1972 and 1981 and those diagnosed between 1982 and 1991. The latter group had significantly worse relative mortality than the former group (P<0.001) but was significantly older at the time of diagnosis (56.94 ± 14.83 vs 52.01 ± 13.58, P<0.001). The serum calcium and serum PTH levels were not significantly different between these two groups.