Background Pathological calcification ((PC), i.e. the deposition of calcium-containing crystals) in tendons is a hallmark of calcific tendinopathy (CT), a disease associated with pain, tendon rupture, and disability. Currently, only symptomatic treatments exist for CT and none of them target specifically calcification. Intriguingly, the gasotransmitter H2S has recently emerged as a potential anti-calcifying molecule [1]. Objectives To establish in CT the potential anti-calcifying effect of hydrogen sulfide (H2S) and of the H2S-producing enzyme cystathionine gamma lyase (CSE), and the underlying mechanisms involved. Methods Wild type (WT) and CSE knock-out (KO) tenocytes were isolated from adult mice Achilles’ tendons. Tenocyte were cultured in αMEM + 10% FBS + 50μg/ml ascorbic acid (Control medium) in presence of 10% calciprotein particles (calcification medium, CM). Spontaneous Achilles’ tendon CT in old mice (35 weeks old) and surgery-induced Achilles’ tendon CT in8-12 weeks old mice were quantified by micro computed tomography. Dynamic Young’s modulus was measured in 35 weeks old mice as previously described [2]. Immunohistochemistry was performed on human and murine tendon sections with anti-CSE and anti-LOX and anti-LOXL2rabbit polyclonal antibodies. LOX expression was analyzed by qPCR and by Western-blot. LOX(L) activity was quantified in cells supernatants and lysates. Results In vitro, tenocyte calcification (in CM) was inhibited by exogenous H2S-donors, while it was exacerbated in CSE KO tenocytes, producing as expected less H2S than WT. Reduced calcification in tenocytes exposed to H2S was accompanied by decreased expression of genes coding for BMP2, BMP4 and decreased activation of the BMP signaling pathway (pSMAD1/5/8). Accordingly, BMPs expression and BMPs-pathway activation were exacerbated in CSE KO tenocytes compared to WT tenocytes. The protective role of CSE-H2S was confirmed in vivo. Indeed, in aged mice, micro computed tomography revealed exacerbated Achilles’ tendon calcification in CSE KO mice compared to WT. Interestingly, CSE deficiency led to reduced biomechanical strength, as the dynamic Young’s modulus was significantly decreased upon increased tendon displacement. Furthermore, using a tenotomy model of CT, we found an inverse correlation between CSE expression and calcification in tendons. This was confirmed in human tendons from CT patients, which exhibited decreased CSE expression where calcification was present. In parallel experiments, we found that calcification in tenocytes was significantly reduced by addition of BAPN, a pan-inhibitor of lysyl oxidases (LOX(L)) enzymes. LOX(L) family includes 5 enzymes LOX and LOX1-4, catalysing elastin and collagen cross-links. We next investigated if the anti-calcfiying effect of H2S in CT could be mediated by inhibition of LOX(L). Indeed, in CM-stimulated tenocytes we found that H2S impacts both LOX/LOX2 expression (as CSE deficiency increased significantly LOX/LOX2 gene expression) and LOX(L) activity (as CSE deficiency increased LOX(L) activity and conversely H2S dose-dependently inhibited LOX(L) activity in WT tenocytes. Finally, in vivo we discovered that, CSE was inversely correlated with calcification and LOX and LOXL2 expression in mouse and human tendons. Conclusion Altogether, our results suggest that increasing H2S levels in tenocytes could represent a future strategy to prevent or decrease calcification in CT, likely via down-modulation of LOX(L) expression and activity. References [1]Castelblanco, M., et al., The role of the gasotransmitter hydrogen sulfide in pathological calcification. Br J Pharmacol, 2020. 177(4): p. 778-792. [2]Kronenberg, D., et al., Increased Collagen Turnover Impairs Tendon Microstructure and Stability in Integrin alpha2beta1-Deficient Mice. Int J Mol Sci, 2020. 21(8). Acknowledgements: NIL. Disclosure of Interests None Declared.

INTRODUCTION:Molecular alterations in follicular cells in the BRAF or NRAS genes have been reported to be associated with the process of carcinogenesis. Our aim was to determine the mutational frequency of BRAF and NRAS in fine-needle aspiration (FNA) specimens in our population.METHODS:The mutational status of BRAF (codon 600) and NRAS (codon 61) was analysed by qPCR in 193 FNA specimens from suspicious nodules and compared with pathological data of 115 patients.RESULTS:BRAF mutation was identified in 40 samples (74.1%) of FNAs classified as Bethesda VI (n = 54). In samples histologically diagnosed as classic papillary thyroid carcinoma (cPTC, n = 47), mutation was observed in 70% of cases, while in other subtypes the prevalence was lower (p = 0.013). In FNA specimens of follicular lesions (n = 36), positivity for NRAS was found in 50% of the follicular carcinomas (FTCs), but only in 6.7% of adenomas. Finally, there was a significant correlation between BRAF and PTC with lymph-node metastasis (p = 0.014) and increased relative risk of recurrence based on the Argentine Intersociety Consensus (RR = 6.77, p = 0.022). No significant differences were found between BRAF mutation and other features of aggressiveness in PTC.CONCLUSION:BRAF and NRAS mutations are observed in a significant number of PTCs and FTCs, in our population. There is a significant correlation between BRAF mutation and lymph-node metastasis.

In patients with low-risk differentiated thyroid cancer (DTC), remnant ablation with radioiodine (RA) after total thyroidectomy (TT) is controversial. No benefits have been demonstrated in terms of mortality or disease-free survival. Recent evidence found that RA did not improve mid-term outcomes. To evaluate initial response to treatment and long-term follow-up status in low-risk DTC patients after TT vs. TT + RA with 131I 1.11 GBq (30 mCi). Prospective multicenter non-randomized study; 174 low-risk DTC that underwent TT were recruited an divided in two groups according to RA (87 ablated and 87 non-ablated). Response to treatment was evaluated at 6–18 months after thyroidectomy and at the end of follow-up with measurements of thyroglobulin, and anti-thyroglobulin antibodies levels, and neck ultrasonography. Baseline characteristics of both groups were similar. Ablated patients: median age 45.5 years, 84

Abstract In patients with low-risk differentiated thyroid cancer (DTC), remnant ablation with radioiodine (RA) after total thyroidectomy (TT) is controversial. No benefits have been demonstrated in terms of mortality or disease-free survival. Recent evidence found that RA did not improve mid-term outcomes. Purpose: to evaluate initial response to treatment and long-term follow-up status in low-risk DTC patients after TT vs. TT+RA. Methods: prospective multicenter non-randomized study; 174 low-risk DTC that underwent TT were recruited and were divided in two groups according to RA (87 ablated and 87 non-ablated). Response to treatment was evaluated between 6-18 months after thyroidectomy and at the end of follow-up with thyroglobulin, anti-thyroglobulin antibodies levels and neck ultrasonography. Results: baseline characteristics of both groups were similar. Ablated patients: median age 45.5 years, 84% females, 95.4% papillary thyroid carcinoma (PTC), mean tumor size 16mm; non-ablated: median age 45 years, 88.5% females, 96.6% PTC, mean tumor size 14 mm. Response to initial treatment was similar between both groups, with less than 2% of structural incomplete response. Final status was evaluated in 139 cases after a median follow-up of 60 months. Among ablated patients, 82.8% had no evidence of disease (NED), 12% had an indeterminate response (IR) and 5% a biochemical incomplete response (BIR). Non-ablated patients had NED in 90%, IR in 8.7% and BIR in 1.2%. No statistical difference was found between groups (p=0.29). No patient had evidence of structural disease at the end of follow-up. Conclusions:our findings support the recommendation against routine RA in low-risk DTC patients.

Abstract   It is known that thyroid cancer initiation and progression occurs because of gradual accumulation of genetic and epigenetic alterations at cell level. Many mutations associated with this disease have been reported to be present in genes encoding proteins in the mitogen-activated protein kinase (MAPK) signaling pathway, specifically BRAF and RAS genes, as well as in the PI3K/Akt signaling pathway, among others. In particular, molecular alterations in follicular cells in the BRAF or NRAS genes have been reported to be associated with the process of carcinogenesis. Previously we found BRAF and NRAS mutations are observed in a significant number of papillary and follicular thyroid carcinomas in our population, respectively. In this study, we tested the diagnostic performance of BRAF and NRAS mutation in thyroid carcinoma in fine-needle aspiration (FNA) specimens with indeterminate cytology. In total, residual material from 73 FNA samples was used (n= 16, Bethesda III; n=48, Bethesda IV and n=9 Bethesda V). BRAF codon 600 mutation and NRAS codon 61 mutations were investigated using qPCR and melting curve analysis was carried out. Diagnosis of malignancy was confirmed by histology on paired surgical specimen in 54 cases. Results In the cytologically indeterminate categories, 9.6% of specimens were BRAF V600 mutated: 1 of 16 were subcategorized as atypia of undetermined significance or follicular lesion of undetermined significance (6.3%); 2 of 48 as follicular neoplasm or suspicious for follicular neoplasm (4.1%); and 4 of 9 as suspicious for malignancy (44.4%). NRAS Q61 mutation was found in 4 patients (2 with Bethesda IV and 2 with cytology V). The BRAF V600 mutations were associated with carcinoma in 100% of cases (n = 7), whereas only 75% (n = 3) of the nodules with NRAS were associated with carcinoma. BRAF V600 and NRAS Q61 mutations had high specificity in predicting malignant carcinoma (96.8%); the sensitivity was 43.5% with a positive predictive value of 90.9% and a negative predictive value of 69.8%. In specific categories of indeterminate cytology, the pre-test risk of malignancy was 38%, 33% and 88% while the post molecular test risk of malignancy was 100%, 75% and 100% respectively. Conclusions BRAF V600 and NRAS Q61 molecular test in residual FNA samples improve diagnostic accuracy of the cytology analysis in our population and may help to better select patients for avoid inadequate or unnecessary surgeries. Presentation: No date and time listed

Purpose Metastases of differentiated thyroid cancer (DTC) in sites different from lungs and bone are unusual (UM); their impact in management and prognosis remains unknown. Our aim was to evaluate the prevalence of UM, to describe their characteristics and to analyze their impact in disease outcome and mortality. Methods We retrospectively reviewed the file records from 8 different centers. Those patients with DTC and UM were included. UM were diagnosed by: (i) biopsy/cytology and/or (ii) radioiodine (RAI) uptake associated to elevated thyroglobulin (Tg) levels and/or c) presence of one or more structural lesion/s with 18-FDG uptake in the PET/CT scan and elevated Tg levels. Results Thirty-six (0.9%) out of a total of 3982 DTC patients were diagnosed with UM; 75% had papillary histology. The most frequent localization was central nervous system (CNS, 31%). UM were metachronous in 75%, symptomatic in 55.6% and fulfilled RAI-refractoriness criteria in 77.8% of cases. Metastatic lesions in lung/bone and/or locoregional disease were present in 34 cases (94.4%). Diagnosis of UM changed the therapeutic approach in 72.2% of patients. After a median follow up of 13 months, 21 (58.3%) patients died from DTC related causes. In 8 of them CNS progression was the immediate cause of death. Conclusions Prevalence of UM was low; they were frequently metachronic and RAI-refractory. Although UM were found in patients with widespread disease, their diagnosis usually led to changes in therapy. UM were associated with poor prognosis and high frequency of disease-specific mortality.

Hyperthyroidism is defined as an excessive production of thyroid hormones by eutopic or ectopic mature thyroid tissue. The overall prevalence of hyperthyroidism is 1.2% and the most common cause is Graves' disease. Struma ovarii represents 1% of all ovarian tumors and is an uncommon cause of ectopic hyperthyroidism. It is benign in >90% of the cases; usually asymptomatic, and only 8% are presented with thyrotoxicosis, being rare its association with Graves' disease. We report the case of a patient with this association.

The aim of the study was to evaluate the association of the body mass index (BMI) with the clinical-pathological characteristics and the recurrence of papillary thyroid carcinoma. The cohort consisted of 208 patients with papillary thyroid carcinoma diagnosed in 2003-2014, in Buenos Aires, Argentina. The patients were grouped according to the BMI as follows: BMI <18.5 kg/m2 (low weight); BMI ≥ 18.5 and < 25 kg/m2 (normal weight); BMI ≥ 25 and < 30 kg/m2 (overweight); BMI ≥ 30 kg/m2 (obesity). Two experienced pathologists reviewed and cross-checked all pathology specimens to confirm diagnosis, tumor characteristics and extent of the disease. All patients were followed every 6 months for 2 years, and annually thereafter. Recurrences were searched by using diagnostic imaging and histological confi rmation when necessary. Regression analysis was applied to defi ne associations of BMI with clinical, pathological, and prognosis features of the disease. A 5-point increase in BMI was significantly associated with tumor size (OR 1.21; 95% CI 1.1-1.5; p = 0.01) and greater extranodal extension in cervical metastases (OR 1.11; 95% CI 1.06-1.21; p = 0.03). The analysis of prognostic variables showed no association between increase in BMI and risk of recurrence (HR 1.11; 95% CI 0.91-1.22). In conclusion, we found that BMI relates directly with tumor size and extranodal extension, but not with recurrence.

Osteonecrosis is an ischemic process in the juxta-articular bone. Two forms of osteonecrosis are distinguished, one in which infarction occurs in bone marrow, causing no clinical signs, and another involving the cortical medulla, with a more florid clinical picture. Multifocal osteonecrosis is defined as a disease affecting three or more separate anatomical regions. Its preferential locations include the femoral head, distal femur, proximal humeri, and calcanei. As regards its pathogenesis, it has been related to long-term corticosteroid treatment, alcohol abuse, hemoglobinopathies, malignant tumors, human immunodeficiency virus, connective tissue disease, Gaucher’s disease, or radiotherapy, with glucocorticoids being one of the causes in 5--25% of cases. No prior trigger is known in 40% of cases, and the condition is then considered idiopathinc.1 We report the case of a 32-year-old female patient who reported mechanical pain in both knees and was referred to the radiodiagnosis department for bilateral magnetic resonance imaging (MRI). Her history included, in addition to smoking five cigarettes daily, an infrachiasmatic suprasellar tumor detected by cranial MRI one year and a half before during work-up for infertility and increased prolactin levels. A pituicytoma inducing panhypopituitarism was diagnosed and surgery was performed. Hormone replacement therapy consisting of different drugs, including hydrocortisone at doses of 20 mg in the morning and 10 mg in the evening, was subsequently administered. Fourteen months later, and without having received higher hydrocortisone doses for any intercurrent condition, bilateral pain in the hips and shoulders (Fig. 1) led to MRI being performed, which revealed avascular necrosis in these locations. Surgery was performed on both heads, consisting of decompression and filling with a bone graft, and hydrocortisone dosage was decreased to 10 mg in the morning and 5 mg in the evening. At the time

Chromogranin A (CgA) is the most abundant granin in gastroenteropancreatic neuroendocrine tumors (GEP-NETs). As a tumor marker is moderately sensitive and nonspecific. Despite the limitations of testing methods, which require careful interpretation, especially in the case of gastrinomas, patients treated with somatostatin analogs, and poorly differentiated tumors, it is the best tumor marker in GEP-NETs and may be of value in other tumors with neuroendocrine differentiation. CgA may be used as a marker in blood or tissue samples through immunohistochemical techniques. CgA levels correlate with tumor burden and extension and may be used for diagnosis and monitoring of GEP-NETs, especially midgut carcinoids and endocrine pancreatic tumors. It is also useful as a prognostic marker for the detection of recurrence and monitoring of response to different treatments.La cromogranina A (CgA) es la granina más abundante en los tumores neuroendocrinos gastroenteropancreáticos (TNE-GEP). Como marcador tumoral es moderadamente sensible y poco específico. A pesar de las limitaciones de los métodos de medida que requieren una interpretación cuidadosa, especialmente en el caso de los gastrinomas, pacientes tratados con análogos de somatostatina y tumores pobremente diferenciados, es el mejor marcador tumoral en los TNE-GEP y puede ser útil en otros tumores con diferenciación neuroendocrina. La CgA puede ser usada como marcador en sangre o en muestra tisular mediante inmunohistoquímica. Las concentraciones se relacionan con la carga y la extensión tumoral y puede ser usada en el diagnóstico y seguimiento de los TNE-GEP, especialmente en los derivados del intestino delgado y neuroendocrinos del páncreas. Además es útil como marcador pronóstico en la detección de recidivas y en la monitorización de la respuesta a los distintos tratamientos.

Thyroid cancer incidence has significantly risen worldwide in the last decades. In Argentina, there is no national cancer registry; therefore its incidence can not be established. The objective of this study was to estimate the incidence of thyroid cancer in the population of Buenos Aires City and suburbs, and the rela- tionship between gender and histology over the period 2003-2011. Assuming that the population affiliated to the Social Security of the Argentine Federal Police is representative of the inhabitants of Buenos Aires City and suburbs, we estimate an incidence of 6.51 cases/100,000 population/year, with an increasing incidence of almost double from 1981-1986 to 2003-2011. An increase in papillary thyroid cancer was mainly responsible for this rising trend. Incidence rates were higher for females (11.76/100,000 women) compared to those for males (2.65/100,000 men). Among men and women of all ages, the highest rate of incidence was for tumor

Thyroid cancer incidence has significantly risen worldwide in the last decades. In Argentina, there is no national cancer registry; therefore its incidence can not be established. The objective of this study was to estimate the incidence of thyroid cancer in the population of Buenos Aires City and suburbs, and the rela- tionship between gender and histology over the period 2003-2011. Assuming that the population affiliated to the Social Security of the Argentine Federal Police is representative of the inhabitants of Buenos Aires City and suburbs, we estimate an incidence of 6.51 cases/100,000 population/year, with an increasing incidence of almost double from 1981-1986 to 2003-2011. An increase in papillary thyroid cancer was mainly responsible for this rising trend. Incidence rates were higher for females (11.76/100,000 women) compared to those for males (2.65/100,000 men). Among men and women of all ages, the highest rate of incidence was for tumor

To supplement limited relevant literature, we retrospectively compared ablation and disease outcomes in high-risk differentiated thyroid carcinoma (DTC) patients undergoing radioiodine thyroid remnant ablation aided by recombinant human thyrotropin (rhTSH) versus thyroid hormone withdrawal/withholding (THW). Our cohort was 45 consecutive antithyroglobulin antibody- (TgAb-) negative, T3-T4/N0-N1-Nx/M0 adults ablated with high activities at three referral centers. Ablation success comprised negative (<1 μg/L) stimulated serum thyroglobulin (Tg) and TgAb, with absent or <0.1% scintigraphic thyroid bed uptake. “No evidence of disease” (NED) comprised negative unstimulated/stimulated Tg and no suspicious neck ultrasonography or pathological imaging or biopsy. “Persistent disease” was failure to achieve NED, “recurrence,” loss of NED status. rhTSH patients (n=18) were oftener ≥45 years old and higher stage (P=0.01), but otherwise not different than THW patients (n=27) at baseline. rhTSH patients were significantly oftener successfully ablated compared to THW patients (83% versus 67%, P<0.02). After respective 3.3 yr and 4.5 yr mean follow-ups (P=0.02), NED was achieved oftener (72% versus 59%) and persistent disease was less frequent in rhTSH patients (22% versus 33%) (both comparisons P=0.03). rhTSH stimulation is associated with at least as good outcomes as is THW in ablation of high-risk DTC patients.

BACKGROUND:Diabetic macular edema (DME) is the main cause of moderate vision loss in type 2 diabetes. Diagnosis is achieved by dilated fundus examination or by measuring retinal thickness. However, it can be identified in nonmydriatic retinography (NMR) with hard exudates as a surrogate marker or macular thickness under stereoscopic vision. To date, few studies have focused on interobserver reliability for DME with this technique.METHODS:Fity-three type 2 diabetes patients with known diabetic retinopathy were studied. We obtained 182 pairs of stereoscopic retinographs with a nonmydriatic camera. Photographic options were 30 degrees or 45 degrees macula-centered retinal field and spontaneous or pharmacological dilation using tropicamide. An endocrinologist with a minimum of training and another with no specific training in this kind of examination diagnosed the images. DME was assumed if retinal thickness was identified within one disc diameter around the fovea.RESULTS:The kappa index agreement between both endocrinologists for all the data was 0.16 (P = 0.02). Depending on the photographic options, all the kappa indices were below 0.25, except for the 45 degrees retinal field under spontaneous mydriasis (0.58) where the number of samples analyzed was reduced to 22.CONCLUSIONS:In our study, endocrinologists with a low level of training did not reach a suitable level of agreement regarding the reliability of stereoscopic NMR as a technique for diagnosing DME. We feel that, as NMR can be performed by various different health providers, it would be advisable to establish generally agreed upon criteria for training staff in this technique.