Co-occurrence of mutations in NF1 and other susceptibility genes in pheochromocytoma and paraganglioma

IntroductionThe percentage of patients diagnosed with pheochromocytoma and paraganglioma (altogether PPGL) carrying known germline mutations in one of the over fifteen susceptibility genes identified to date has dramatically increased during the last two decades, accounting for up to 35-40% of PPGL patients. Moreover, the application of NGS to the diagnosis of PPGL detects unexpected co-occurrences of pathogenic allelic variants in different susceptibility genes.MethodsHerein we uncover several cases with dual mutations in NF1 and other PPGL genes by targeted sequencing. We studied the molecular characteristics of the tumours with co-occurrent mutations, using omic tools to gain insight into the role of these events in tumour development.ResultsAmongst 23 patients carrying germline NF1 mutations, targeted sequencing revealed additional pathogenic germline variants in DLST (n=1) and MDH2 (n=2), and two somatic mutations in H3-3A and PRKAR1A. Three additional patients, with somatic mutations in NF1 were found carrying germline pathogenic mutations in SDHB or DLST, and a somatic truncating mutation in ATRX. Two of the cases with dual germline mutations showed multiple pheochromocytomas or extra-adrenal paragangliomas - an extremely rare clinical finding in NF1 patients. Transcriptional and methylation profiling and metabolite assessment showed an “intermediate signature” to suggest that both variants had a pathological role in tumour development.DiscussionIn conclusion, mutations affecting genes involved in different pathways (pseudohypoxic and receptor tyrosine kinase signalling) co-occurring in the same patient could provide a selective advantage for the development of PPGL, and explain the variable expressivity and incomplete penetrance observed in some patients

Graves’ Ophthalmopathy: VISA versus EUGOGO Classification, Assessment, and Management

Graves’ ophthalmopathy (GO) is an autoimmune inflammatory disorder associated with thyroid disease which affects ocular and orbital tissues. GO follows a biphasic course in which an initial active phase of progression is followed by a subsequent partial regression and a static inactive phase. Although the majority of GO patients have a mild, self-limiting, and nonprogressive ocular involvement, about 3–7% of GO patients exhibit a severe sight-threatening form of the disease due to corneal exposure or compressive optic neuropathy. An appropriate assessment of both severity and activity of the disease warrants an adequate treatment. The VISA (vision, inflammation, strabismus, and appearance), and the European Group of Graves’ Orbitopathy (EUGOGO) classifications are the two widely used grading systems conceived to assess the activity and severity of GO and guide the therapeutic decision making. A critical analysis of classification, assessment, and management systems is reported. A simplified “GO activity assessment checklist” for routine clinical practice is proposed. Current treatments are reviewed and management guidelines according to the severity and activity of the disease are provided. New treatment modalities such as specific monoclonal antibodies, TSH-R antagonists, and other immunomodulatory agents show a promising outcome for GO patients

Circulating Concentrations of GDF11 are Positively Associated with TSH Levels in Humans

Growth differentiation factor 11 (GDF11) is a member of the transforming growth factor (TGF)-β superfamily which declines with age and has been proposed as an anti-aging factor with regenerative effects in skeletal muscle in mice. However, recent data in humans and mice are conflicting, casting doubts about its true functional actions. The aim of the present study was to analyze the potential involvement of GFD11 in energy homeostasis in particular in relation with thyroid hormones. Serum concentrations of GDF11 were measured by enzyme-linked immunosorbent assay (ELISA) in 287 subjects. A highly significant positive correlation was found between GDF11 and thyroid-stimulating hormone (TSH) concentrations (r = 0.40, p < 0.001). Neither resting energy expenditure (REE) nor REE per unit of fat-free mass (REE/FFM) were significantly correlated (p > 0.05 for both) with GDF11 levels. In a multiple linear regression analysis, the model that best predicted logGDF11 included logTSH, leptin, body mass index (BMI), age, and C-reactive protein (logCRP). This model explained 37% of the total variability of logGDF11 concentrations (p < 0.001), with only logTSH being a significant predictor of logGDF11. After segregating subjects by TSH levels, those within the low TSH group exhibited significantly decreased (p < 0.05) GDF11 concentrations as compared to the normal TSH group or the high TSH group. A significant correlation of GDF11 levels with logCRP (r = 0.19, p = 0.025) was found. GDF11 levels were not related to the presence of hypertension or cardiopathy. In conclusion, our results show that circulating concentrations of GDF11 are closely associated with TSH concentrations and reduced in subjects with low TSH levels. However, GDF11 is not related to the regulation of energy expenditure. Our data also suggest that GDF11 may be involved in the regulation of inflammation, without relation to cardiac function. Further research is needed to elucidate the role of GDF11 in metabolism and its potential involvement in thyroid pathophysiology

Clinical and Ultrasound Thyroid Nodule Characteristics and Their Association with Cytological and Histopathological Outcomes: A Retrospective Multicenter Study in High-Resolution Thyroid Nodule Clinics

Introduction: Thyroid nodules are a common finding. A high-resolution thyroid nodule clinic (HR-TNC) condenses all tests required for the evaluation of thyroid nodules into a single appointment. We aimed to evaluate the clinical outcomes at HR-TNCs. Design and Methods: A retrospective cross-sectional multicenter study including data from four HR-TNCs in Spain. We evaluated fine-needle aspiration (FNA) indications and the association between clinical and ultrasound characteristics with cytological and histopathological outcomes. Results: A total of 2809 thyroid nodules were included; FNA was performed in 82.1%. Thyroid nodules that underwent FNA were more likely larger, isoechoic, with microcalcifications, and in younger subjects. The rate of nondiagnostic FNA was 4.3%. A solid component, irregular margins or microcalcifications, significantly increased the odds of Bethesda IV-V-VI (vs. Bethesda II). Irregular margins and a solid component were independently associated with increased odds of malignancy. Thyroid nodules <20 mm and ≥20–<40 mm had a 6.5-fold and 3.3-fold increased risk for malignancy respectively in comparison with those ≥40 mm. Conclusion: In this large multicenter study, we found that the presence of a solid component and irregular margins are factors independently related to malignancy in thyroid nodules. Since nodule size ≥40 mm was associated with the lowest odds of malignancy, this cut-off should not be a factor leading to indicate thyroid surgery. HR-TNCs were associated with a low rate of nondiagnostic FNA