1,721,036 research outputs found
The 5th edition of WHO classification of tumors of endocrine organs: changes in the diagnosis of follicular-derived thyroid carcinoma
No full textThe 5(th) edition of the World Health Organization (WHO) classification of endocrine tumors was released in 2022. Several novelties have been introduced concerning the nomenclature and histopathological diagnosis of follicular-derived thyroid neoplasms. Tumor types have been sharply classified according to prognostic risk categories into benign tumors, low-risk neoplasms and malignant neoplasms. A grading system for differentiated thyroid carcinomas has been implemented with the aim of improving the stratification of tumors. Particular attention has been paid to the molecular profile of well-differentiated histotypes. In this review, the main changes introduced by the latest edition of the WHO system are presented. The practical effects on the diagnostic pathology of thyroid tumors, along with the clinical implications expected with the new classification scheme, are critically discussed
Diagnosis of post-surgical fine-needle aspiration biopsies of thyroid lesions with indeterminate cytology using HRMAS NMR-based metabolomics
No full textIntroduction: Ultrasound examination coupled with fine-needle aspiration (FNA) cytology is the gold standard for the diagnosis of thyroid cancer. However, about 10–40% of these analyses cannot be conclusive on the malignancy of the lesions and lead to surgery. The cytological indeterminate FNA biopsies are mainly constituted of follicular—patterned lesions, which are benign in 80% of the cases. Objectives: The development of a FNAB classification approach based on the metabolic phenotype of the lesions, complementary to cytology and other molecular tests in order to limit the number of patients undergoing unnecessary thyroidectomy. Methods: We explored the potential of a NMR-based metabolomics approach to improve the quality of the diagnosis from FNABs, using thyroid tissues collected post-surgically. Results: The NMR-detected metabolites were used to produce a robust OPLSDA model to discriminate between benign and malignant tumours. Malignancy was correlated with amino acids such as tyrosine, serine, alanine, leucine and phenylalanine and anti-correlated with myo-inositol, scyllo-inositol and citrate. Diagnosis accuracy was of 84.8% when only indeterminate lesions were considered. Conclusion: These results on model FNAB indicate that there is a clear interest in exploring the possibility to export NMR metabolomics to pre-surgical diagnostics
BRAF(K601E) Mutation in a Follicular Thyroid Adenoma
No full textBRAF mutations represent the most common genetic alteration in papillary thyroid carcinoma (PTC). The p.V600E mutation is specific for the classic and tall-cell variants of PTC and has been associated with a more aggressive biologic behavior. On the other hand, the p.K601E mutation is peculiar to the follicular variant of PTC, and seems to be a favorable prognostic indicator. A 12-year-old boy presented with a 10-mm left-sided thyroid nodule. Fine-needle aspiration cytology reported the lesion as suspicious for a follicular neoplasm (Bethesda category IV). The patient underwent lobectomy, and histopathology revealed a follicular adenoma with normal surrounding tissue. The cytological smear was found to be positive for BRAF p.K601E mutation, and this was later confirmed on the corresponding paraffin block. This case was independently revised by 4 expert pathologists, all of whom confirmed the benign nature of the thyroid lesion. This article describes the presence of a BRAF mutation in a benign thyroid lesion. To the authors' knowledge, this is the fourth case of follicular adenoma carrying BRAF(K601E) reported in literature to date. BRAF(K601E) mutation can occur in benign thyroid lesions. This finding, in the context of the current literature and the recently proposed reclassification of the noninvasive encapsulated follicular variant of papillary thyroid carcinoma into a benign lesion, confirms the importance of preoperative BRAF p.K601E testing in offering patients a tailored treatment plan and avoiding overtreatment
Differential expression of RET isoforms in normal thyroid tissues, papillary and medullary thyroid carcinomas
No full textPOURPOSES:
We investigated the expression of RET9 and RET51 isoforms in medullary (MTC), papillary (PTC) thyroid carcinoma, normal thyroid tissues, and pheochromocytoma (PHEO) to verify if these isoforms are present also in follicular thyroid cell-derived tissues, and if there is a differential expression of RET9 and RET51 in MTC.
METHODS:
Nineteen patients with MTC, 18 patients with PTC, 18 samples of contralateral normal thyroid tissues, and 5 cases of PHEO were included in this study. RET isoform expression was studied by real-time RT-PCR.
RESULTS:
All MTCs and PHEOs were positive for RET9 and RET51. Fourteen/eighteen (77.7%) PTC cases were positive for RET9 and/or RET51, and four were positive for only one of the genes. In normal thyroid tissues, 3/18 (16.7%) cases were negative for both isoforms, 4/18 (22.2%) were positive for both, and 11/18 (61.1%) were positive for only one. RET isoforms were expressed at different levels in MTC, PHEO, PTC, and normal thyroid tissues: RET9 expression was higher in PHEO than in MTC, PTC, and normal thyroid tissues. RET9 expression was also higher in MTC than in PTC and normal thyroid tissues. No difference was observed between PTC and normal thyroid tissues. A similar pattern of expression was observed for RET51. In addition, RET51 was significantly more expressed than RET9 in MTC, while RET9 was the predominant isoform in PHEO.
CONCLUSIONS:
Our study documented the expression of the RET9 and RET51 isoforms in normal thyroid and PTC tissues. RET9 and RET51 isoforms were also present in MTC and PHEO. RET51 expression was higher than RET9 expression in MTC, while there was no difference in the expression of these two isoforms in PTC and normal thyroid tissues. RET9 was more highly expressed than RET51 in PHEOs
Hippo pathway affects survival of cancer patients: Extensive analysis of TCGA data and review of literature
Full text linkThe disruption of the Hippo pathway occurs in many cancer types and is associated with cancer progression. Herein, we investigated the impact of 32 Hippo genes on overall survival (OS) of cancer patients, by both analysing data from The Cancer Genome Atlas (TCGA) and reviewing the related literature. mRNA and protein expression data of all solid tumors except pure sarcomas were downloaded from TCGA database. Thirty-Two Hippo genes were considered; for each gene, patients were dichotomized based on median expression value. Survival analyses were performed to identify independent predictors, taking into account the main clinical-pathological features affecting OS. Finally, independent predictors were correlated with YAP1 oncoprotein expression. At least one of the Hippo genes is an independent prognostic factor in 12 out of 13 considered tumor datasets. mRNA levels of the independent predictors coherently correlate with YAP1 in glioma, kidney renal clear cell, head and neck, and bladder cancer. Moreover, literature data revealed the association between YAP1 levels and OS in gastric, colorectal, hepatocellular, pancreatic, and lung cancer. Herein, we identified cancers in which Hippo pathway affects OS; these cancers should be candidates for YAP1 inhibitors development and testing
DICER1 somatic mutations strongly impair miRNA processing even in benign thyroid lesions
Full text linkThe alteration of miRNA processing is a driver event in several tumors including thyroid cancer. In particular, somatic DICER1 mutations, reported in follicular-patterned lesions, are shared by benign as well as malignant tumors. In the present study, we investigated the effects of alterations in the miRNA processing genes on the miRNA profile. The study included 19 follicular adenomas (FAs) and 22 follicular variant of papillary thyroid carcinomas (FVPTCs). The mutational status in the hot spot regions of DICER1, DROSHA, TARBP2, DGCR8 and the most commonly affected genes in thyroid tumors was investigated on both tumor and paired normal tissues. The miRNA profile and the mRNA expression levels of DICER1, DROSHA, TARBP2, DGCR8 and XPO5 were also evaluated. Two DICER1 RNase IIIb domain mutations were found in FAs. These lesions presented a considerable loss of 5p miRNAs. Fifteen miRNAs were specifically deregulated in DICER1-mutant lesions compared to FAs and FVPTCs. These miRNAs regulate crucial pathways in cancer such as Hippo, p53 and TGF-beta signalling. DICER1 somatic mutations in the RNase IIIb domain are not specific for malignancy, but the miRNA imbalance that they cause is remarkable, especially with regard to the loss of 5p miRNAs. DICER1-mutant lesions have a characteristic miRNA deregulation, which is different from that of FVPTCs; nevertheless, this impairment is consistent with malignant transformation. Further studies providing the real risk of malignancy associated with DICER1 mutations and the evolution of DICER1-mutant lesions are needed to make them useful in the clinical practice
Metastasis of renal cell carcinoma to the parathyroid gland 16 years after radical nephrectomy: A case report
No full textRenal cell carcinoma (RCC) has a high metastatic potential, and most commonly metastasizes via the bloodstream, although lymphatic metastases also occur. RCC is well-known for its propensity to metastasize to unusual sites, and late metastasis, even after a number of years, is common. The occurrence of RCC metastasis to the head and neck region is uncommon, and occurs primarily in the thyroid gland and in patients with widespread dissemination. Involvement of the parathyroid gland in metastatic carcinoma is extremely rare. In the present report, a case of metastasis confined to the parathyroid gland is described, likely with intrathyroidal localization, arising from a RCC that occurred 16 years after nephrectomy. A 66-year-old man was referred to the Department of Surgery of the University Hospital of Pisa (Pisa, Italy) with a preoperative fineneedle aspiration diagnosis of a follicular lesion in the context of nodular goiter of the thyroid gland. The previous medical history of the patient included a right nephrectomy for the treatment of clear cell RCC in February 1997. No other distant metastases were identified as of the latest followup in March 2014. At the time of thyroid surgery, the thyroid and parathyroid function tests were normal. The gross appearance of the surgical specimen was a multinodular goiter with a solid nodule measuring 33 mm on the left lobe of the thyroid gland. Microscopic examination revealed a completely encapsulated lesion consisting of clear cells arranged in a solid pattern and intermixed with fragments of parathyroid tissue. Following immunohistochemical examination, the clear cell lesion was negative for thyroid transcription factor-1 and thyroglobulin and strongly positive for epithelial membrane antigen, cluster of differentiation 10 and vimentin. To the best of our knowledge,this is the second case of metastasis to the parathyroid gland from a RCC reported in the literature
'Incidental' and 'non-incidental' thyroid papillary microcarcinomas are two different entities
Full text linkPapillary thyroid microcarcinomas (microPTC) may be 'incidental' (Inc-microPTC), occasionally found at histology after surgery for benign disease or 'non-incidental' (Non-Inc-microPTC), diagnosed on clinical grounds. It is unclear whether these different microPTC reflect the same disease. The aim of the study was to compare Inc-microPTC and Non-Inc-microPTC for clinical and histological features as well as for serum TSH, a known factor involved in PTC development
Genetic heterogeneity of Medullary Thyroid Carcinoma
No full textGenetic intratumor heterogeneity has been recently demonstrated in some solid human cancers and a few years ago RET mutated and not mutated cells were described in medullary thyroid carcinoma (MTC). Nobody reported the presence of two different RET mutations
Aim of our study was to investigate the RET somatic mutation profile in primary MTC (pMTC) and in the corresponding metastatic tissues (mets).
We studied pMTC and mets of 22 MTC sporadic cases. Altogether 86 samples were screened for the presence of a RET somatic mutations in exons 10, 11, 13-16.
In 18 cases (81.8%), 57 different tissues, a correspondent mutation profile was found in the pMTC and in their mets. In 4 cases (18.2%), 29 different tissues, a different RET mutation profile was observed in pMTC and in their mets. In particular in one case a M918T was found in the pMTC but only in 3/5 lymphnode mets; in another case, a 3 bp in frame deletion in exon 15 was found in 8 lymphnode mets but not in the primary tumor and in 4 additional lymphnode mets. Interestingly we found one patient with a S891A somatic mutation in the primary tumor that was absent in a kidney distant metastases that was indeed characterized by the presence of a M918T mutation. A complex genetic heterogeneity was finally demonstrated in one MTC patient with a very severe disease. The primary tumor displayed a heterozygous 6 bp in frame deletion in exon 11 that was found also in 4/5 lymphnode metastases and in 1/2 liver met. In 1/5 lymphnode and in 1/2 liver metastasis the deletion was homozygous. The analysis of several RET SNPs demonstrated that in this case one RET allele was missing determining loss of heterozigosity. In addition both the primary tissue and 4 lymph node metastases harbored a V804M mutation.
In conclusion our study shows that a) 82% of cases had a correspondent RET mutation profile, although in these cases we cannot exclude the simultaneous presence of RET positive and RET negative cells; b) 19% of cases are clearly heterogeneous and among them 2/4 have different RET mutations in different tissues. This information should be taken into consideration in the planning of personalized target therapies and raise the question of whether RET mutations play a real driving role in the development of MTC
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