Oncocytic Follicular Carcinoma Research Articles

Oncocytic Follicular Cell-Derived Thyroid Tumors With Papillary Growth Pattern: A Clinicopathologic Study of 32 Cases.

Oncocytic thyroid tumors displaying a papillary growth pattern are rare and may cause diagnostic problems. To examine the clinicopathologic features of a series of 32 follicular cell-derived tumors composed of cells with oncocytic cytoplasm and displaying papillary architecture. Thirty-two cases were collected and studied to assess clinicopathologic features, including immunohistochemical and molecular testing for BRAF V600E. The patients were 26 women and 6 men, aged 17 to 77 years. The nodules ranged from 0.3 to 6.0 cm. Eighteen cases showed features of oncocytic hyperplastic nodules and were identified against a background of thyroid follicular nodular disease; 4 cases showed features of oncocytic follicular adenoma; and 10 cases corresponded to carcinomas with oncocytic and papillary features. Nuclear features of papillary thyroid carcinoma were absent or exceedingly rare. All cases were negative for HBME-1 and cytokeratin 19 (CK19) and wild type for BRAF V600E. Follow-up in 25 patients showed that all patients with hyperplastic nodules and oncocytic follicular adenomas were alive and well and free of disease from 7 to 20 years. One patient with oncocytic follicular carcinoma showed metastases and died of tumor at 16 months; 2 patients with carcinoma had metastases and recurrence at 6 and 7 years; and 5 patients with invasive tumors were free of disease from 5 to 10 years. Oncocytic thyroid tumors with papillary features can span a spectrum from benign hyperplastic, to encapsulated neoplastic, to invasive malignant lesions. Owing to their papillary features, it is important not to confuse them for other types of thyroid tumors, such as oncocytic papillary thyroid carcinoma.

Expanding the Spectrum of BRAF Non-V600E Mutations in Thyroid Nodules: Evidence-Based Data from a Tertiary Referral Centre.

The BRAF p.V600E mutation represents the most specific marker for papillary thyroid carcinoma and is potentially related to aggressive behavior and persistent disease. BRAF alterations other than the p.V600E are less common in thyroid carcinoma and represent an alternative mechanism of BRAF activation with unclear clinical significance. The study aims to describe the frequency and clinicopathologic characteristics of BRAF non-V600E mutations in a large cohort (1654 samples) of thyroid lesions characterized by next-generation sequencing. BRAF mutations have been found in 20.3% (337/1654) of thyroid nodules, including classic (p.V600E) mutation in 19.2% (317/1654) of samples and non-V600E variants in 1.1% of cases (19/1654). BRAF non-V600E alterations include 5 cases harboring p.K601E, 2 harboring p.V600K substitutions, 2 with a p.K601G variant, and 10 cases with other BRAF non-V600E alterations. BRAF non-V600E mutations have been reported in one case of follicular adenoma, three cases of conventional papillary thyroid carcinoma, eight cases of follicular variant of papillary carcinomas, one case of columnar cell variant papillary thyroid carcinoma, one case of oncocytic follicular carcinoma, and two bone metastasis of follicular thyroid carcinoma. We confirm that BRAF non-V600E mutations are uncommon and typically found in indolent follicular-patterned tumors. Indeed, we show that BRAF non-V600E mutations can be found in tumors with metastatic potential. However, in both aggressive cases, the BRAF mutations were concomitant with other molecular alterations, such as TERT promoter mutation.

Update regarding the role of PD-L1 in oncocytic thyroid lesions on cytological samples

AimsSeveral papers have shown that programmed death-ligand 1 (PD-L1) expression is a relevant predictive biomarker in anti-PD-L1 cancer immunotherapy. While its role in several human cancers is correlated with poor...

PD-L1 and thyroid cytology: A possible diagnostic and prognostic marker.

Programmed death-ligand 1 (PD-L1) expression is emerging as an important predictive biomarker in anti-PD-L1 cancer immunotherapy. Its role has been clearly defined in various human cancers and is linked to a poor prognosis and resistance to anticancer therapies. The role of PD-L1 in thyroid cancers has not been well defined in fine-needle aspiration cytology (FNAC). The authors examined the performance of PD-L1 immunostaining in liquid-based cytology (LBC) to determine whether it could be a biomarker of malignancy or aggressive disease. From January 2018 to March 2019, 236 thyroid lesions, which had been diagnosed by FNAC as indeterminate lesions, suspicious for malignancy (SFM), and malignant, were enrolled. PD-L1 immunostaining was performed on both LBC and corresponding histology samples. The FNAC cohort included 50 benign negative controls, 42 samples of atypia of undetermined significance/follicular lesion of undetermined significance (AUS/FLUS), 33 samples of follicular neoplasm/suspicious for follicular neoplasm (FN/SFN), 53 samples that were suspicious for malignancy (SFM), and 58 malignant samples. AUS/FLUS samples included 3 goiters, 32 follicular adenomas (FAs), 1 noninvasive follicular thyroid neoplasm with papillary-like nuclear features (NIFTP), 5 invasive follicular variants of papillary thyroid carcinoma (I-FVPTCs), and 1 follicular carcinoma; whereas FN/SFN samples included 24 FAs and 9 malignancies (4 I-FVPTCs, 1 NIFTP, 3 papillary thyroid carcinomas [PTCs], and 1 oncocytic follicular carcinoma). The 53 SFM samples were diagnosed on histopathology as 2 FAs, 5 NIFTPs, 15 I-FVPTCs, and 31 PTCs; whereas the 58 malignant specimens included 5 NIFTPs, 5 I-FVPTCs, and 48 PTCs. Increased plasma membrane and cytoplasmic PD-L1 expression was found in 79 cases (38.5%), including 61 PTCs (conventional and variants). Negative PD-L1 expression was found in NIFTPs and FAs. A BRAF V600E mutation was identified in 15% of PD-L1-positive malignancies. The current data suggest that PD-L1 expression in the thyroid gland might represent a marker of malignancy that correlates with PTC, but not with NIFTP. Thyroid neoplasms with PD-L1 expression also ae enriched with BRAF V600E mutations, suggesting that they are associated with more aggressive behavior.

Comparison of irisin hormone expression between thyroid cancer tissues and oncocytic variant cells.

Objective: The incidence of thyroid cancer has been continuously increasing. The main objective of this study was to investigate irisin expression in various thyroid pathologies and to compare these expression patterns with irisin expression in healthy thyroid tissues.Methods: The study groups consisted of 20 cases each of control thyroid tissue, Hashimoto’s thyroiditis, thyroid papillary carcinoma, oncocytic papillary carcinoma, follicular thyroid carcinoma, oncocytic follicular thyroid carcinoma, medullary thyroid carcinoma, anaplastic thyroid carcinoma. Irisin expression was evaluated using immunohistochemistry. Irisin levels in thyroid tissue supernatants were measured using ELISA.Results: Patients with HT showed increased irisin expression compared with controls (p<0.05). In addition, mild immunoreactivity was observed in the thyroid tissues of patients with papillary carcinoma while significantly increased irisin immunoreactivity was observed tissues of patients with oncocytic papillary carcinoma (p<0.05). There was no difference in irisin immunoreactivity in thyroid tissues between patients with follicular carcinoma and controls. However, irisin immunoreactivity was higher in tissues of patients with oncocytic follicular carcinoma than in tissues of patients with follicular carcinoma (p<0.05). No irisin immunoreactivity was observed in tissues of patients with medullary carcinoma, a malignant tumor the thyroid; however, irisin expression was significantly increased in tissues of patients with anaplastic carcinoma compared with that in tissues of controls (p<0.05). Furthermore, in all thyroid tissues with irisin expression, irisin immunoreactivity was observed in follicular cells, indicating that irisin is produced by these cells.Conclusion: Irisin is a novel potential immunohistochemical marker for differentiating oncocytic variants of papillary and FTCs from papillary and follicular thyroid cancers.

EXPRESSION OF MENIN IN THE HUMAN THYROID GLAND.

The expression of menin in the thyroid gland has long been debated. Animal models with targeted inactivation of menin in the thyroid gland have shown that its inactivation might play a role in the progression to a more aggressive type of cancer. Human studies are conflicting, some have identified mutations in the MEN1 gene in a sub-type of oncocytic thyroid carcinomas, while others have not identified a higher prevalence of thyroid cancer in MEN1 patients. To analyze the immunohistochemical expression of menin in different types of thyroid carcinomas. 48 thyroid tumours (12 papillary thyroid carcinomas (PTC), 6 anaplastic thyroid carcinomas (ATC), 12 poorly differentiated thyroid carcinomas (PDTC), 5 medullary thyroid carcinomas (MTC), 5 oncocytic follicular carcinomas (OC), 3 oncocytic adenomas (OA) and 5 goiters (G)) were tested for nuclear expression of menin using an anti-menin antibody. The expression was considered positive, negative or decreased. The expression of menin was positive, identical to normal tissue, in 39 cases (81.25%). The expression was decreased (n=8) or absent (n=1) in 9 tumours (18.75% - 2 PTC, 5 PDTC, 2 OC) accounting for 42% (5/12) of the PDTC and 40% (2/5) of the OC. Our results show that the expression of menin is generally preserved in human thyroid carcinomas, but it can be decreased or absent in certain types of thyroid cancer. Further molecular studies are needed to evaluate to potential of menin protein in tumorigenesis.

PTEN and TP53 Mutations in Oncocytic Follicular Carcinoma.

Oncocytic follicular carcinoma (OFC)/Hürthle cell carcinoma represents 3-4 % thyroid carcinomas and can be associated with more aggressive behavior and compromised survival compared to non-oncocytic thyroid carcinoma. In this study, we utilized targeted next-generation sequencing to investigate the molecular alterations in a heterogeneous group of clinically aggressive OFC. A total of 12 cases of OFC were included in this study. Targeted next-generation sequencing was performed using panels of 47 or 20 genes, which are frequently mutated in solid tumors. The case cohort comprised eight cases of angioinvasive OFC, two cases of poorly differentiated OFC, one case of OFC with anaplastic change, and one case of OFC with capsular invasion only. Five out of 12 cases (42 %) harbored TP53 mutation. PTEN mutations were also seen in three cases with TP53 mutation (25 %). Based on this study, TP53 and PTEN are possibly involved in the pathogenesis of OFC. Further studies on a larger case cohort are needed to further elucidate this mechanism and its effect on clinical behavior of these intriguing tumors.

The reliability of thyroid nodule ultrasound features and size to predict malignancy in fine needle aspiration specimens: Practical utility for the evaluating pathologist.

The prognostic impact of ultrasound features of thyroid nodules is debated. We explore the correlation between nodule size, echogenicity on US, and malignancy. We performed a retrospective review of thyroid nodules undergoing ultrasound guided FNA (US-FNA) at our institution between 01/2008-05/2013. In all, 2,403 nodules from 2,293 patients (age range 14-91, mean 54, median 56, M: F-1:3.2) underwent US-FNA. 766 nodules were resected, 337 were malignant (size range 0.4-8.7 cm, median 2 cm, mean 2.37 cm,) and 429 were benign (size range 0.5-9.7 cm, median 2.5 cm, mean 2.79 cm). The malignant diagnoses included: classical variant of PTC 77 (size range 0.5-5.5 cm, mean 1.5 cm), follicular variant of PTC 209 (size range 0.14-7.5 cm, mean 2.1 cm), tall cell variant of PTC 7 (size range 0.5-2.4 cm, mean1.4 cm), poorly differentiated carcinoma 5 (size range 5-8.7 cm, mean 6.42 cm), follicular carcinoma 27 (size range 0.5-7 cm, mean 3.03 cm), and oncocytic follicular carcinoma 9 cases (size range 1.4-7.2 cm, mean 3.2 cm). Of the malignant nodules with echogenicity reported on US, 93 were hypoechoic, 26 hyperechoic, 20 isoechoic, and 76 heteroechoic; increased vascularity on US was seen in 69/337 (20%). On US, 105 benign nodules were reported as hypoechoic, 35 hyperechoic, 43 isoechoic, and 100 as heterogeneous; increased vascularity on US was seen in 88/429 (20%). A malignant diagnosis was more common in thyroid nodules ≤1.0 cm. No differences were noted in the US-features of benign and malignant thyroid nodules.

Targeted Next-Generation Sequencing Panel (ThyroSeq) for Detection of Mutations in Thyroid Cancer

Next-generation sequencing (NGS) allows for high-throughput sequencing analysis of large regions of the human genome. We explored the use of targeted NGS for simultaneous testing for multiple mutations in thyroid cancer. A custom panel (ThyroSeq) was designed to target 12 cancer genes with 284 mutational hot spots. Sequencing was performed to analyze DNA from 228 thyroid neoplastic and nonneoplastic samples including 105 frozen, 72 formalin-fixed, and 51 fine-needle aspiration samples representing all major types of thyroid cancer. Only 5-10 ng of input DNA was sufficient for successful analysis of 99.6% of samples. The analytical accuracy for mutation detection was 100% with the sensitivity of 3%-5% of mutant allele. ThyroSeq DNA assay identified mutations in 19 of 27 of classic papillary thyroid carcinomas (PTCs) (70%), 25 of 30 follicular variant PTCs (83%), 14 of 18 conventional (78%) and 7 of 18 oncocytic follicular carcinomas (39%), 3 of 10 poorly differentiated carcinomas (30%), 20 of 27 anaplastic (ATCs) (74%), and 11 of 15 medullary thyroid carcinomas (73%). In contrast, 5 of 83 benign nodules (6%) were positive for mutations. Most tumors had a single mutation, whereas several ATCs and PTCs demonstrated two or three mutations. The most common mutations detected were BRAF and RAS followed by PIK3CA, TP53, TSHR, PTEN, GNAS, CTNNB1, and RET. The BRAF mutant allele frequency was 18%-48% in PTCs and was lower in ATCs. The ThyroSeq NGS panel allows simultaneous testing for multiple mutations with high accuracy and sensitivity, requires a small amount of DNA and can be performed in a variety of thyroid tissue and fine-needle aspiration samples, and provides quantitative assessment of mutant alleles. Using this approach, the point mutations were detected in 30%-83% of specific types of thyroid cancer and in only 6% of benign thyroid nodules and were shown to be present in the majority of cells within the cancer nodule.

Relative sensitivity of thyroid fine‐needle aspiration by tumor type and size

Fine-needle aspiration (FNA) of papillary thyroid carcinoma (PTC) has high sensitivity. Previous studies demonstrated correlation between FNA sensitivity and PTC size, and lower sensitivity for follicular variant of PTC (FVPTC). Data are lacking for other types of thyroid carcinomas. 996 resected thyroid carcinomas at two institutions (6- and 10-year periods) were correlated with FNA diagnoses and clinical and radiologic data to determine sensitivity for each malignancy type. There were 867 PTCs (371 FVPTC), 101 follicular carcinomas (FCs) (31 oncocytic), 16 medullary carcinomas, and 12 poorly differentiated carcinomas (PDCAR). Mean size of classical PTC (CPTC; 1.9 cm) was smaller than FVPTC (2.2 cm), FC (3.0 cm), oncocytic FC (3.0 cm), and PDCAR (2.8 cm) (P<0.003 each), but not medullary carcinoma (1.7 cm) (P=0.45). Sensitivity was higher for CPTC (88%), compared to FVPTC (78%; P<0.0001) and FC (71%; P=0.0006) and was lower for FC than PDCAR (100%; P<0.04). For tumors ≤1.0 cm, FNA sensitivity for CPTC was higher than for FVPTC (P=0.02). For tumors 1.1-2.9 cm, sensitivity for CPTC was better than FVPTC (P=0.0001) and FC (P=0.0008). Between size groups, only CPTC showed a significant change with decreased sensitivity for tumors ≥3.0 cm (P<0.003). FNA is more sensitive for CPTC, PDCAR, and medullary carcinoma. For CPTC, FNA sensitivity is highest for tumors 1.1-2.9 cm. FNA sensitivity is higher for CPTC than FVPTC for nodules <3.0 cm. FNA sensitivity is lower for FC than CPTC and PDCAR.

MicroRNA Expression Array Identifies Novel Diagnostic Markers for Conventional and Oncocytic Follicular Thyroid Carcinomas

The most difficult thyroid tumors to be diagnosed by cytology and histology are conventional follicular carcinomas (cFTCs) and oncocytic follicular carcinomas (oFTCs). Several microRNAs (miRNAs) have been previously found to be consistently deregulated in papillary thyroid carcinomas; however, very limited information is available for cFTC and oFTC. The aim of this study was to explore miRNA deregulation and find candidate miRNA markers for follicular carcinomas that can be used diagnostically. Thirty-eight follicular thyroid carcinomas (21 cFTCs, 17 oFTCs) and 10 normal thyroid tissue samples were studied for expression of 381 miRNAs using human microarray assays. Expression of deregulated miRNAs was confirmed by individual RT-PCR assays in all samples. In addition, 11 follicular adenomas, two hyperplastic nodules (HNs), and 19 fine-needle aspiration samples were studied for expression of novel miRNA markers detected in this study. The unsupervised hierarchical clustering analysis demonstrated individual clusters for cFTC and oFTC, indicating the difference in miRNA expression between these tumor types. Both cFTCs and oFTCs showed an up-regulation of miR-182/-183/-221/-222/-125a-3p and a down-regulation of miR-542-5p/-574-3p/-455/-199a. Novel miRNA (miR-885-5p) was found to be strongly up-regulated (>40-fold) in oFTCs but not in cFTCs, follicular adenomas, and HNs. The classification and regression tree algorithm applied to fine-needle aspiration samples demonstrated that three dysregulated miRNAs (miR-885-5p/-221/-574-3p) allowed distinguishing follicular thyroid carcinomas from benign HNs with high accuracy. In this study we demonstrate that different histopathological types of follicular thyroid carcinomas have distinct miRNA expression profiles. MiR-885-5p is highly up-regulated in oncocytic follicular carcinomas and may serve as a diagnostic marker for these tumors. A small set of deregulated miRNAs allows for an accurate discrimination between follicular carcinomas and hyperplastic nodules and can be used diagnostically in fine-needle aspiration biopsies.

Genome Haploidisation with Chromosome 7 Retention in Oncocytic Follicular Thyroid Carcinoma

BackgroundRecurrent non-medullary thyroid carcinoma (NMTC) is a rare disease. We initially characterized 27 recurrent NMTC: 13 papillary thyroid cancers (PTC), 10 oncocytic follicular carcinomas (FTC-OV), and 4 non-oncocytic follicular carcinomas (FTC). A validation cohort composed of benign and malignant (both recurrent and non-recurrent) thyroid tumours was subsequently analysed (n = 20).MethodsData from genome-wide SNP arrays and flow cytometry were combined to determine the chromosomal dosage (allelic state) in these tumours, including mutation analysis of components of PIK3CA/AKT and MAPK pathways.ResultsAll FTC-OVs showed a very distinct pattern of genomic alterations. Ten out of 10 FTC-OV cases showed near-haploidisation with or without subsequent genome endoreduplication. Near-haploidisation was seen in 5/10 as extensive chromosome-wide monosomy (allelic state [A]) with near-haploid DNA indices and retention of especially chromosome 7 (seen as a heterozygous allelic state [AB]). In the remaining 5/10 chromosomal allelic states AA with near diploid DNA indices were seen with allelic state AABB of chromosome 7, suggesting endoreduplication after preceding haploidisation. The latter was supported by the presence of both near-haploid and endoreduplicated tumour fractions in some of the cases. Results were confirmed using FISH analysis. Relatively to FTC-OV limited numbers of genomic alterations were identified in other types of recurrent NMTC studied, except for chromosome 22q which showed alterations in 6 of 13 PTCs. Only two HRAS, but no mutations of EGFR or BRAF were found in FTC-OV. The validation cohort showed two additional tumours with the distinct pattern of genomic alterations (both with oncocytic features and recurrent).ConclusionsWe demonstrate that recurrent FTC-OV is frequently characterised by genome-wide DNA haploidisation, heterozygous retention of chromosome 7, and endoreduplication of a near-haploid genome. Whether normal gene dosage on especially chromosome 7 (containing EGFR, BRAF, cMET) is crucial for FTC-OV tumour survival is an important topic for future research.MicroarraysData are made available at GEO (GSE31828).

Expression of telomerase genes in thyroid carcinoma

Telomerase (T) is a ribonucleoprotein complex that includes the telomerase RNA component (hTR), telomerase associated protein (TP1) and the telomerase catalytic subunit (hTERT). Telomerase has been shown in stem cells and found to be activated in tumor tissues and immortalized cells. We wanted to test whether the expression of the telomerase complex subunits correlate with the enzyme activity in human thyroid tissue. Hence, we determined the expression of hTERT, hTR and TP1 mRNA by RT-PCR and compared the results to telomerase activity as detected by the telomeric repeat amplification protocol (TRAP) assay. Fifteen benign goiters (G), 11 follicular carcinomas (FTC) including 2 oncocytic follicular carcinomas (also called Hurthle cell carcinoma, oFTC), 12 papillary carcinomas (PTC) including 3 microcarcinomas (mPTC), and 12 undifferentiated anaplastic thyroid carcinomas (UTC) were investigated. Experienced pathologists performed histological and pTNM classification in each specimen. RT-PCR analysis revealed that TP1 was ubiquitously expressed in all G and carcinomas. hTR was expressed in 4 out of 15 G, in 2 out of 3 mPTC, in 5 out of 9 PTC, in 5 out of 9 FTC, in all oFTC and in 9 out of 12 UTC samples. Regarding all carcinomas, no statistically significant correlation was observed between hTR-expression and tumor stage, lymph node or distant metastasis. hTERT-expression was associated with malignancy and tumor stage. All mPTC and 13 out of 15 G did not express hTERT, whereas all samples of pT3-4 tumor stage of FTC, PTC, UTC and all oFTC were positive for hTERT. No telomerase activity could be detected in G. Telomerase activity in carcinoma was only measurable in tissues that expressed the catalytic subunit hTERT. Our data indicate that telomerase activity is up-regulated in neoplastic cells. In contrast to TP1 and hTR, hTERT and telomerase activity may be of help in identifying invasive tumors and may be additional markers for classification of benign goiter and malignant thyroid carcinoma.