[Exploration and management of thyroid nodules]. / Exploration et prise en charge des nodules thyroïdiens.

EXPLORATION AND MANAGEMENT OF THYROID NODULES. Most thyroid nodules are benign (95%) and can benefit from clinical and ultrasound monitoring. Cancers (approximately 5% of nodules) could be suspected, particularly in subjects whose neck was irradiated, in cases of a hard, irregular, evolving nodule, or with very high serum calcitonin (> 100 pg/ml). It is crucial to recognize cancers when nodules exceed the supracentimeter stage. Thyroid ultrasonography is the most common, handy, safe, and cost-effective tool to image thyroid nodules. It classifies thyroid nodules according to the EU-TIRADS score, which comprises 5 categories associated with an increasing risk of malignancy. An ultrasound-guided fine needle aspiration (FNA) biopsy is performed only in nodules staged EU-TIRADS classes 5, 4, and 3 over 1, 1.5, and 2 cm, respectively. Cytologic analysis of FNA material classifies thyroid nodules according to the Bethesda system into 6 classes, each with its own prognostic value. The difficulties in cytological evaluation are related to the uninterpretable (Bethesda I) and indeterminate (especially III and IV) results, for which have to be discussed opportunities of reassessment and follow-up by scintiscans and cytological molecular markers. Management is imperfectly codifiable: from surveillance in the absence of suspicious elements initially to total thyroidectomy in their presence.

EXPLORATION ET PRISE EN CHARGE DES NODULES THYROÏDIENS. La plupart des nodules thyroïdiens sont bénins (95 %) et peuvent bénéficier d'une surveillance clinique et échographique. La malignité (5 % des nodules environ) est à suspecter, particulièrement chez les sujets dont le cou a été irradié, en cas de nodule dur, irrégulier, évolutif, avec une calcitoninémie très élevée (supérieure à 100 pg/mL). C'est au stade de nodule supracentimétrique qu'il importe de reconnaître les cancers. L'échographie est l'examen d'imagerie de référence ; elle permet de classer les nodules selon le score EU-TIRADS, composé de cinq catégories associées à un risque croissant de malignité. Les ponctions échoguidées en vue de l'analyse cytologique sont réservées aux catégories EU-TIRADS 5, 4 et 3 de plus de 1, 1,5 et 2 cm respectivement. Les caractéristiques cytologiques sont présentées selon la nomenclature de Bethesda en six classes dont chacune quantifie aussi le risque de malignité, en complément des données échographiques. Les difficultés de l'évaluation cytologique sont liées aux résultats ininterprétables (Bethesda I) et indéterminés (surtout Bethesda III et IV) pour lesquels se discutent l'opportunité de la réévaluation et de la surveillance, des scintigraphies dites de seconde intention, et également des marqueurs moléculaires sur le produit de cytoponction. La prise en charge est imparfaitement codifiable : de la surveillance en l'absence d'éléments suspects initialement à la thyroïdectomie totale en leur présence.

Quantitative dual isotope 123iodine/99mTc-MIBI scintigraphy: A new approach to rule out malignancy in thyroid nodules.

BACKGROUND: The aim of this study was to evaluate the role of dual isotope 123Iodine/99mTc-MIBI thyroid scintigraphy (IMS) in discriminating between malignant and benign lesions in indeterminate nodules using quantitative analysis methods. METHODS: Thirty-five consecutive patients with thyroid nodules of indeterminate or non-diagnostic cytology and cold on 123Iodine scintigraphy (10 Bethesda I, 24 Bethesda III-IV, 1 in which cytology was impossible) underwent IMS between 2017 and 2019 with uptake quantification at two time points ahead of thyroidectomy: early and late. Images were analyzed by two blinded physicians. RESULTS: Twelve nodules were malignant and 23 benign on histopathology. Mean uptake values were lower in benign than in malignant nodules at both time points: early, 8.7±4.1 versus 12.9±3.5 (P=0.005); and late, 5.3±2.7 versus 7.7±1.1 (P=0.008). Interobserver reproducibility was excellent. The intraclass correlation coefficient was 0.86 in benign and 0.92 in malignant lesions for early uptake result (ER) and 0.94 and 0.85 respectively for late uptake result (LR). The optimal LR cut-off  to exclude a diagnosis of malignancy was set at 5.9 . The sensitivity, specificity, positive predictive value, negative predictive value and accuracy of this cut-off were, respectively, 100%, 65.2%, 60%, 100% and 77.1%. CONCLUSION: Despite some study limitations, quantitative analysis of 99mTc-MIBI thyroid scintigraphy had a good reproducibility, which could help to rule out malignancy in non-diagnostic or indeterminate thyroid nodules and thereby reducing the number of patients undergoing unnecessary surgery when LR is below 5.9.

Chronic Mucocutaneous Candidiasis in Autoimmune Polyendocrine Syndrome Type 1.

Autoimmune polyendocrinopathy candidiasis ectodermal dystrophy (APECED) is an autosomal recessive disease caused by mutations in the autoimmune regulator (AIRE) gene, characterized by the clinical triad of chronic mucocutaneous candidiasis (CMC), hypoparathyroidism, and adrenal insufficiency. CMC can be complicated by systemic candidiasis or oral squamous cell carcinoma (SCC), and may lead to death. The role of chronic Candida infection in the etiopathogenesis of oral SCC is unclear. Long-term use of fluconazole has led to the emergence of Candida albicans strains with decreased susceptibility to azoles. CMC is associated with an impaired Th17 cell response; however, it remains unclear whether decreased serum IL-17 and IL-22 levels are related to a defect in cytokine production or to neutralizing autoantibodies resulting from mutations in the AIRE gene.

Large sporadic thyroid medullary carcinomas: predictive factors for lymph node involvement.

Lymph node involvement (LNI) is one of the most important prognostic factors for poor survival in medullary thyroid carcinoma (MTC). At diagnosis, LNI is found in over 50% of sporadic MTCs, and especially in large tumours. Cervical lymph node dissection is therefore mandatory during MTC surgery. However, some large tumours (responsible for high preoperative basal calcitonin levels) are found to lack LNI, and can be cured definitely. Preoperative detection of these particular tumours might spare patients from undergoing extensive cervical dissection. The objective of the present retrospective study of a series of large sporadic MTCs was to identify clinical, biological and pathological factors that were predictive of LNI. Consecutive cases of large, sporadic MTCs (measuring at least 1 cm in diameter) were retrieved and reviewed. The levels of several mature microRNAs (miRs) in paraffin-embedded samples were assessed using qPCR. Of the 54 MTCs, 26 had LNI and 28 were pN0. Relative to pN0 patients, patients with LNI had a significant higher preoperative basal calcitonin level (p = 0.0074) and a greater prevalence of infiltrative margins (p < 0.0001), lymphovascular invasion (p = 0.0004), extrathyroidal extension (p < 0.0001), a higher pT stage (p = 0.0003) and more abundant desmoplastic stroma (p = 0.0006). Tumour expression levels of miR-21 (p = 0.0008) and miR-183 (p = 0.0096) were higher in the LNI group. The abundance of desmoplastic stroma (p = 0.007) and the miR-21 expression level (p = 0.0026) were independent prognostic factors for LNI. The abundance of desmoplastic stroma and high levels of miR-21 expression were strong indicators of LNI, and may thus help the surgeon to choose the extent of cervical lymph node dissection for large, sporadic MTCs with no preoperatively obvious LNI.

[Oral and dental expression of thyroid diseases]. / Manifestations buccodentaires des maladies thyroïdiennes.

Oral disorders were observed in children with congenital hypothyroidism, lately apparent because of difficulties of feeding, swallowing disorders, and macroglossia. Macroglossia was also a component of the severe acquired myxedema, particularly observed in hypothyroidism related to autoimmune atrophic thyroiditis beyond menopause. Lingual ectopy in children and adults could determine respiratory gene or swallowing difficulties, and were detectable by visual examination and the endobuccal touch. Expression of these events was completely minimized since the neonatal screening of congenital hypothyroidism, also by the common practice in adults of serum TSH determinations. Congenital and acquired hormonal deficits are now early detected and correct with suppletive doses of levothyroxine. Oral expression of hyperthyroidism is poor, even if thyrotoxicosis is sometimes revealed by increased thirst. Caution is required for dental care, mainly due to changes in the hemostatic functions. Finally, a genetic predisposition to the medullary thyroid cancer may be revealed by an oral and neuromatosis. Radioisotopic therapy of thyroid cancers is likely to alter the salivation.

[Maxillary, buccal and dental expressions of hyperparathyroidisms]. / Manifestations maxillo-buccodentaires des hyperparathyroïdies.

States of chronic parathyroid hypersecretion, related to a primitive parathyroid abnormality (adenoma, hyperplasia), or to a cause of chronic calcipenia (renal failure, vitamin D deficiency…) have a major impact on bone remodeling, alveolodental structures. Thinning of the lamina dura, maxillary or mandibular brown tumors, giant cell epulis are the most emblematic signs of the primary hyperparathyroidism. Other expressions are related to genetic factors such as fibrous tumors of the jaw in conjunction with mutations in the gene coding for parafibromin.

Pendred syndrome.

Pendred syndrome is an autosomal recessive disorder that is classically defined by the combination of sensorineural deafness/hearing impairment, goiter, and an abnormal organification of iodide with or without hypothyroidism. The hallmark of the syndrome is the impaired hearing, which is associated with inner ear malformations such as an enlarged vestibular aqueduct (EVA). The thyroid phenotype is variable and may be modified by the nutritional iodine intake. Pendred syndrome is caused by biallelic mutations in the SLC26A4/PDS gene, which encodes the multifunctional anion exchanger pendrin. Pendrin has affinity for chloride, iodide, and bicarbonate, among other anions. In the inner ear, pendrin functions as a chloride/bicarbonate exchanger that is essential for maintaining the composition and the potential of the endolymph. In the thyroid, pendrin is expressed at the apical membrane of thyroid cells facing the follicular lumen. Functional studies have demonstrated that pendrin can mediate iodide efflux in heterologous cells. This, together with the thyroid phenotype observed in humans (goiter, impaired iodine organification) suggests that pendrin could be involved in iodide efflux into the lumen, one of the steps required for thyroid hormone synthesis. Iodide efflux can, however, also occur in the absence of pendrin suggesting that other exchangers or channels are involved. It has been suggested that Anoctamin 1 (ANO1/TMEM16A), a calcium-activated anion channel, which is also expressed at the apical membrane of thyrocytes, could participate in mediating apical efflux. In the kidney, pendrin is involved in bicarbonate secretion and chloride reabsorption. While there is no renal phenotype under basal conditions, severe metabolic alkalosis has been reported in Pendred syndrome patients exposed to an increased alkali load. This review provides an overview on the clinical spectrum of Pendred syndrome, the functional data on pendrin with a focus on its potential role in the thyroid, as well as the controversy surrounding the relative physiological roles of pendrin and anoctamin.

A multicenter phase II study of sunitinib in patients with locally advanced or metastatic differentiated, anaplastic or medullary thyroid carcinomas: mature data from the THYSU study.

PURPOSE: Patients with advanced radioactive iodine resistant differentiated (MDTC) or medullary (MMTC) thyroid cancer had an unmet need. Early data showed promising efficacy of vascular endothelial growth factor receptor inhibitors. We investigated sunitinib in this setting. PATIENTS AND METHODS: This phase 2 trial enrolled MDTC, anaplastic (MATC) and MMTC patients in 1st line anti-angiogenic therapy with sunitinib at 50 mg/d, 4/6w. Objective response rate was the primary end-point. Secondary end-points were progression-free survival, overall survival and safety. RESULTS: Seventy-one patients were enrolled from August 2007 to October 2009, 41 MDTC/4 MATC patients and 26 MMTC patients. Patients received a median of 8 and 9 cycles, respectively. In the MDTC/MATC group, 13% of patients and 43% of cycles and in the MMTC group, 23% of the patients and 48.8% of cycles remained at 50 mg/d, respectively. The primary end-point was reached with an objective response rate of 22% (95% CI: 10.6-37.6) in MDTC patients and in 38.5% (95% CI: 22.6-56.4) in MMTC patients. No objective response was seen in MATC patients. Median progression-free survival and overall survival were 13.1 and 26.4 months in MDTC patients, 16.5 and 29.4 months in MMTC patients. The most frequent side effects were asthenia/fatigue (27.8% ≥ grade 3), mucosal (9.9% ≥ grade 3), cutaneous toxicities, hand-foot syndrome (18.3% ≥ grade 3). Of all, 14.1% had a cardiac event. Nine unexpected side effects were reported, out of which, five induced deaths. CONCLUSION: Sunitinib is active in MDTC and MMTC patients. Side effects were more severe than with previous reports. If using sunitinib, alternative schedule/dosage should be considered.

Multiple HABP2 variants in familial papillary thyroid carcinoma: Contribution of a group of "thyroid-checked" controls.

A heterozygous germline variant in the HABP2 gene c.1601G > A (p.Gly534Glu), which negatively impacts its tumor suppressive activity in vitro, has been described in 4-14% of kindreds of European-American ancestry with familial papillary thyroid carcinoma (fPTC). But it is also found in ≈4% of Europeans and European/Americans from public databases that, however, did not provide information on the thyroid function of the controls. To get unbiased results, we decided to compare HABP2 genotypes of patients with fPTC with those of "thyroid-checked" controls. A control group consisting of 136 European patients who were thyroidectomised for medullary thyroid carcinoma and devoid of any histologically detectable PTC or follicular-deriving carcinoma was built. In parallel we recruited 20 patients with fPTC from eleven independent European kindreds. The entire coding region of HABP2 was analyzed by Sanger sequencing the germline DNAs of patients. Nucleotide variants were searched for by Snap Shot analysis in the controls. Two variants, c.1601G > A (p.Gly534Glu) and c.364C > T (p.Arg122Trp), were found in 2 and 3 patients at the heterozygous level respectively (minor allele frequency (MAF): 5.0% and 7.5%, respectively). In controls, the MAF was either similar for the c.1601G > A HABP2 variant (2.94%, ns) or significantly lower for the c.364C > T variant (0.73%, p = 0.016). The Arg122 residue lies in the EGF-3 domain of HABP2 which is important for its activation but, however, superposition of the predicted 3D structures of the wild type and mutated proteins suggests that this variant is tolerated at the protein level. In conclusion, our data do not support the pathogenicity of the HABP2 c.1601G > A variant but highlight the existence of a new one that should be more extensively searched for in fPTC patients and its pathogenicity more carefully evaluated.

[Advances in thyroglobulin assays and their impact on the management of differentiated thyroid cancers]. / Avancées dans les dosages de thyroglobuline et leur impact dans la prise en charge des cancers différenciés de la thyroïde.

Thyroglobulin (Tg) is a high molecular weight glycoprotein located mainly in thyroid follicles, where thyroid hormones are synthesized and stored. In patients with differentiated thyroid cancer of follicular origin, serum Tg levels become undetectable following total thyroidectomy and iodine-131 remnant ablation. It is a key biomarker to follow-up patients with differentiated thyroid cancer, in combination with neck ultrasound monitoring. The measurement of Tg in the wash-out of the needle used for fine needle aspiration biopsy is a valuable aid to the diagnosis of lymph node metastasis. The presence of anti-thyroglobulin antibodies affects reliability of Tg results measured in serum or plasma. Systematic investigation of such antibodies is required to validate any Tg assay. Elevated or rising levels of anti-thyroglobulin antibodies can in turn be used as a surrogate tumor marker of thyroid cancer. The development of second-generation Tg assay (automated, highly sensitive) has enabled significant advances in the management of differentiated thyroid cancer: early detection of persistent or recurrent disease and follow-up care simplified in low-risk patients. Testing of serum Tg can also be useful in evaluating other clinical situations such as congenital hypothyroidism, endemic goiter and thyrotoxicosis factitia.

TRα receptor mutations extend the spectrum of syndromes of reduced sensitivity to thyroid hormone.

Since 2012, eight different abnormalities have been described in the THRA gene (encoding the TRα1 thyroid hormone receptor) of 14 patients from 9 families. These mutations induce a clinical phenotype (resistance to thyroid hormone type α) associating symptoms of untreated mild congenital hypothyroidism and a near-normal range of free and total thyroid hormones and TSH (the T4/T3 ratio is nevertheless usually low). The phenotype can diversely include short stature (due to growth retardation), dysmorphic syndrome (face and limb extremities), psychoneuromotor disorders, constipation and bradycardia. The identified genetic abnormalities are located within the ligand-binding domain and result in defective T3 binding, an abnormally strong interaction with corepressors and a dominant negative activity against still functional receptors. The identification of patients with consistent phenotypes and the underlying mutations are warranted to better delineate the spectrum of the syndromes of reduced sensitivity to thyroid hormone.

Is surgery necessary for 'mild' or 'asymptomatic' hyperparathyroidism?

A large majority of the currently diagnosed patients with hyperparathyroidism (PHPT) are mild or asymptomatic, mainly women after menopause. Following the debate held at the 16th European Congress of Endocrinology in Wroclaw (Poland) from May 3-7, 2014, arguments are here presented by a surgeon and a medical practitioner considering these situations rather have to profit from surgery, or simply from survey. For the trained endocrine surgeon, it is evident that parathyroidectomy confirms the diagnosis and undoubtedly reduces the discomfort felt by certain patients, prevents all risks of complications, removes patients and medical teams from the monitoring and represents a real individual financial benefit. On the other hand, the medical practitioner considers that mild or asymptomatic PHPT is commonly stable, and very rare are the subjects at risk of complications, particularly of fractures; prevention of vascular and metabolic disorders, nephrolithiasis and bone rarefaction justify regular physical exercise, a safe alimentation, a sufficient calcium and high water intake, the correction of the frequent deficit in vitamin D; finally has also to be considered the impossibility to refer to specialized (endocrine) surgeons, the enormous cohort of subjects more than 50 years with 'mild' or 'asymptomatic' PHPT. The surgeon and the medical practitioner agree to consider that in patients with 'mild' or 'asymptomatic' disease, there is no place for medical treatments, in particular calcimimetics and bisphophonates. Both agree that further studies are needed to clarify the long-term prognosis of operated and non-operated PHPT in term of fractures, cardiovascular risk and mortality. Individual and collective cost/benefit ratios of surgery or survey are also still imperfectly evaluated.

A Novel Mutation in THRA Gene Associated With an Atypical Phenotype of Resistance to Thyroid Hormone.

CONTEXT: RTHα is a recently discovered resistance to thyroid hormone (RTH) due to mutation of THRA, the gene encoding TRα1, the thyroid hormone receptor. It has been described in a few patients with growth retardation, short stature, and a low free T4/free T3 (FT4/FT3) ratio. OBJECTIVE: A 27-year-old patient presenting with dwarfism and a low FT4/FT3 ratio was investigated. DESIGN: Clinical, biochemical, and radiological data were collected. Whole exome sequencing was performed in the patient and her relatives. RESULTS: The patient exhibited congenital macrocytic anemia and severe bone malformation with growth retardation, dwarfism, clavicular agenesis, and abnormalities of the fingers, toes, and elbow joints. In adulthood, she presented with active behavior, chronic motor diarrhea, and hypercalcemia. Treatment with T3 led to heart rate acceleration, worsening of diarrhea, and TSH suppression. Low resting energy expenditure normalized on T3. rT3, SHBG, and IGF-1 remained normal. A de novo monoallelic missense mutation in THRA was discovered, the N359Y amino acid substitution (c.1075A>T), which affected both the TRα1 and the non-receptor isoform TRα2. The mutant TRα1 had a decrease in transcriptional activity related to decreased T3 binding and a dominant-negative effect on the wild-type receptor. CONCLUSIONS: This patient presents a new phenotype including more significant bone abnormalities, lower TSH, and higher FT3 levels, without certainty of all her symptoms with the TRα1(N359Y) mutation. This case suggests that patients with a low FT4/FT3 ratio should be screened for THRA mutations, even if clinical and biological features differ from previous reported cases of RTHα.

[Autoimmune thyroiditis]. / Fréquentes et le plus souvent bénignes, elles imposent une surveillance annuelle de la valeur de la TSH. Thyroïdites auto-immunes.

Autoimmune thyroiditis are common and benign disorders, affecting preferentially women, at any age of life. They may occur singly or integrated as a part of familial predisposition to autoimmune thyroid disease or autoimmune polyendocrinopathies. Clinical presentation is variable: goiter or thyroid atrophy, euthyroid or temporary or permanent hypothyroidism, rarely transient thyrotoxicosis. Commune features are the presence of antithyroperoxydase antibodies and lymphoplasmocytic infiltrate of the thyroid parenchyma. It is important to distinguish the cases in which thyroid dysfunction is transient and requires only monitoring and those in which hypothyroidism is permanent and justifies thyroid hormone replacement. In the forms with goiter, clinical and ultrasonic control of the thyroid is justified.

MUC1 expression in papillary thyroid carcinoma is associated with BRAF mutation and lymph node metastasis; the latter is the most important risk factor of relapse.

BACKGROUND: The incidence of papillary thyroid carcinoma (PTC) has increased over the past 30 years in Western countries. PTC is usually associated with a good prognosis, but there is a wide range of aggressiveness, and some patients develop distant metastasis and/or resistance to standard treatment. Early identification of these high-risk tumors is a current challenge for appropriate patient management. MUC1 expression has been studied previously in thyroid cancer, but its prognostic value remains controversial. Here, we correlated MUC1 expression in PTC with clinical and pathological features and with the presence of the BRAF(V600E) mutation. METHODS: We performed a clinical and morphological analysis of 190 thyroid tumors (95 PTCs and 95 adenomas). MUC1 immunohistochemistry was carried out on a tissue microarray using different antibodies. The presence of the BRAF(V600E) mutation was investigated by pyrosequencing. MUC1 mRNA levels were assessed by quantitative reverse transcription polymerase chain reaction on a subset of PTC. RESULTS: MUC1 expression was observed in 49% of PTCs and was found to correlate with the presence of papillary architecture, a stromal lymphoid infiltrate, aggressive histological subtypes, extrathyroidal extension, lymph node metastasis, nuclear pseudoinclusions, lymphovascular invasion, and the presence of the BRAF(V600E) mutation (p<0.0001). MUC1 was abundant in nuclear pseudoinclusions. Multivariate analysis showed a strong association of MUC1 expression with the presence of the BRAF(V600E) mutation and lymph node metastasis (p<0.0001). Lymph node metastasis was the most important risk factor of relapse. CONCLUSIONS: Our study shows an association between MUC1 expression and the presence of the BRAF(V600E) mutation in PTC. Analysis of MUC1 expression could improve the risk stratification of PTCs.

Coexistence of thyroid-stimulating hormone-secreting pituitary adenoma and graves' hyperthyroidism.

BACKGROUND: Coexistence of thyroid-stimulating hormone (TSH)-secreting pituitary adenoma (TSHoma) with Graves' disease has been rarely reported. We describe a female patient displaying TSHoma with Graves' disease and who presented initially with inappropriate TSH values. CASE REPORT: A 36-year-old woman presented with signs of thyrotoxicosis, small and vascular goiter and mild bilateral exophthalmos. Thyroid function tests showed hyperthyroxinemia and normal TSH values despite the use of different assays. Heterophile antibody testing result was negative. The patient underwent total right lobectomy with partial left lobectomy after 18 months of carbimazole treatment. Histology confirmed Graves' disease. Symptoms of thyrotoxicosis recurred 2 months later. Thyroid function tests showed hyperthyroxinemia and elevated TSH values. Investigations were consistent with a 10-mm TSHoma. The patient underwent a trans-sphenoidal tumor resection following preoperative lanreotide preparation. Histological examination and immunocytochemistry concluded to a pure TSH-producing tumor. There was no evidence of tumor recurrence after 18 years of follow-up. CONCLUSION: Association of TSHoma with Graves' disease should be carefully taken into account, especially when TSH values are not compatible with either the clinical history or other thyroid functions tests.

[Biological diagnosis of pheochromocytoma in 2014]. / Le diagnostic biologique de phéochromocytome en 2014.

Pheochromocytomas and/or paragangliomas are rare, heterogeneous tumors of the chromaffin cells. Thirty percent of the patients presented with these diseases in a hereditary context. The biological diagnosis relies on the identification of excessive secretion of the metanephrines which are more sensitive and specific than those of catecholamines. The published recommendations give the opportunity to choose between the metanephrines in sera or urines. The concentrations of the free plasmatic metanephrines reflect the ongoing production of tumor. They are little sensitive to the renal failure. The gold standard method to measure the free metaphrines in plasma is the LC-MS/MS chromatography. This is the technical event that we use since 2008, and we relate our experience.