Cytopathology of non‐invasive follicular thyroid neoplasm with papillary‐like nuclear features: A comparative study with similar patterned papillary thyroid carcinoma variants

Objective

Noninvasive follicular thyroid neoplasm with papillary‐like nuclear features (NIFTP) is a recently described, indolent thyroid tumor, with well‐defined histopathological diagnostic criteria. Cytology features are not well documented. We reviewed cytology of histologically proven cases of NIFTP and some of its common differentials to look for salient diagnostic features.

Methods

Cases reported on histopathology as follicular variant of papillary thyroid carcinoma (FVPTC), or NIFTP between July 2015 and April 2017 having available cytology smears were retrieved and reclassified as NIFTP, FVPTC, and classical papillary thyroid carcinoma with predominant follicular pattern (PTC‐FP). Cytological features were assessed, classified as per The Bethesda System for Reporting Cytopathology and compared.

Results

There were 23 NIFTP cases, 18 FVPTC and 8 PTC‐FP. A microfollicle‐predominant pattern was seen in all. Nuclear score was 2 in most NIFTP cases (61%). Pseudoinclusions were absent. NIFTP showed features of atypia of undetermined significance/follicular lesion of undetermined significance (AUS/FLUS) (III) in 61%, follicular neoplasm/suspicious for a follicular neoplasm (FN/SFN) (IV) in 35% and suspicious for malignancy (SFM) (V) in 4%. Most of the FVPTCs were also called FN/SFN (IV) (56%) or AUS/FLUS (III) (22%). Nuclear features did not statistically differ from NIFTP. PTC‐FP showed high‐grade cytology in 75%, and higher nuclear score (3 in 75%) in contrast to NIFTP (P = .003).

Conclusion

NIFTP and FVPTC show a similar distribution among the Bethesda categories hence precluding conclusive distinction on cytology. PTC‐FP, in contrast, was found to have a statistically significant higher nuclear score and more commonly showed malignant cytology.

     

The impact of the non‐invasive follicular thyroid neoplasm with papillary‐like nuclear feature terminology in the routine diagnosis of thyroid tumours

Background

Due to the recent proposal of the non‐invasive follicular thyroid neoplasm with papillary‐like nuclear feature (NIFTP) category, the authors analyse the state of the art in the challenging diagnosis of follicular thyroid neoplasms in routine practice.

Methods and results

A consecutive series of 200 histological diagnoses, with complete cytological correlation, was analysed following the introduction of the NIFTP definition. The study was conducted in a general hospital with a high prevalence of thyroid benign nodules that accounted for approximately 60% of surgically‐treated nodules. The significant incidence of the new NIFTP category was 7%. Concurrently, a gradual decrease of the follicular variant of papillary thyroid carcinoma (fvPTC) was observed (3.5%). When evaluating the FNA biopsies within the NIFTP group, despite the systematic evaluation of nuclear crowding, enlargement, irregularities and clearing, the final cytological class was often indeterminate for malignancy (Thy3/III‐IV, 71%). At histology, the application of the semiquantitative NIFTP score for the evaluation of the PTC‐like nuclear features was able to discriminate benign lesions (score 0/1) from fvPTC (score 2/3). A certain degree of overlapping still persisted between NIFTP and fvPTC (score 2) or between NIFTP and benign lesions (score 1).

Conclusions

In the routine evaluation of FNA biopsies, the presence of subtle and questionable PTC‐like nuclear features still remains a controversial aspect of the diagnostic workflow. Given that the NIFTP category was introduced to stratify the low‐risk group of thyroid tumours more precisely, pathologists should force themselves to apply the nuclear score rigorously and to classify cases assigned a score of 1 as benign proliferations.

     

Adenoid cystic pattern in follicular variant of papillary thyroid carcinoma: a report of four cases

S. Mandal, and S. Jain
Adenoid cystic pattern in follicular variant of papillary thyroid carcinoma: a report of four cases Objective: An adenoid cystic pattern in thyroid tumours is a rare finding that may be seen in papillary carcinoma of thyroid (PCT), the follicular variant of PCT (FV‐PCT), a rare cribriform‐morular variant of papillary carcinoma of thyroid (CMV‐PCT) and follicular carcinoma. There is little published cytological literature describing these patterns. We report four cases of PCT with this unusual pattern. Methods: Fine needle aspiration (FNA) cytology was performed on four patients with a neck lump using a 22‐G needle; smears were stained with Giemsa and Papanicolaou stains. Immunocytochemical staining for thyroglobulin was done in all cases. Results: The patients were female and ranged in age from 18 to 46 years. They presented with a gradually increasing mass in the neck. FNA smears in all cases showed nuclear features of PCT. There were also prominent follicular areas with hyaline globules in some of the cell clusters reminiscent of adenoid cystic carcinoma and, in places, morula‐like groups of neoplastic cells were also seen. Immunocytochemistry for thyroglobulin was positive in all cases but negative in the hyaline globules. Conclusions: Adenoid cystic areas with morula‐like groups in PCT are a rare finding. Cytopathologists and clinicians should be aware of these distinct features in thyroid tumours to avoid diagnosing metastatic adenoid cystic carcinoma. It is also important to rule out CMV‐PCT since that variant is mostly associated with familial adenomatous polyposis, although sporadic occurrence is known.     

Pre‐operative features of non‐invasive follicular thyroid neoplasms with papillary‐like nuclear features: An analysis of their cytological,Gene Expression Classifier and sonographic findings

Objective

To investigate the corresponding cytological diagnoses, Gene Expression Classifier (GEC) results and ultrasound features of thyroid nodules diagnosed as non‐invasive follicular thyroid neoplasms with papillary‐like nuclear features (NIFTP), as well as any coexisting pathology.

Methods

We performed a retrospective review of thyroid nodules histologically diagnosed as NIFTP at our institution between 1^st April 2016 and 1^st April 2017. The following data points were collected: demographics, nodule size, ultrasound features, cytological diagnosis, GEC results, origin of sample (in‐house vs outside hospital) and any additional pathology identified in the resection specimen.

Results

The case cohort included 87 nodules diagnosed as NIFTP (size range: 1‐7 cm, mean: 2.5 cm) from 82 patients (age range: 22‐82, mean age: 50.4, M:F—1:4.1). Corresponding FNA results were available for 72 nodules (82.8%) and were categorised as follows: benign (n = 5, 6.9%), atypia of unknown significance/follicular lesion of undetermined significance (n = 29, 40.3%), follicular neoplasm/suspicious for follicular neoplasm/follicular neoplasm with oncocytic features (n = 27, 37.5%), suspicious for papillary thyroid carcinoma (n = 6, 8.3%) and malignant (n = 5, 6.9%). GEC results were available for 32 (44.4%) nodules, with the majority of cases classified as suspicious (81.3%). On ultrasound, most of the nodules were predominantly solid (81.8%), vascular (93.8%), non‐calcified (86.5%), and either hypoechoic (44.9%) or isoechoic (38.8%). In addition to NIFTP and other benign findings in the background thyroid, 75 separate malignant tumours were identified in 38 (46.3%) patients, many of which were papillary thyroid microcarcinomas (86.5%) with lymph node metastases present in two cases.

Conclusions

The majority of thyroid nodules histologically diagnosed as NIFTP have indeterminate cytology (77.8%) and are classified as suspicious (81.3%) by GEC testing. Taken together, these findings can guide clinicians toward a more conservative therapeutic approach.

     

Mutual regulation of TGF-β1, TβRII and ErbB receptors expression in human thyroid carcinomas

The role of EGF and TGF-β1 in thyroid cancer is still not clearly defined. TGF-β1 inhibited the cellular growth and migration of follicular (FTC-133) and papillary (B-CPAP) thyroid carcinoma cell lines. Co-treatments of TGF-β1 and EGF inhibited proliferation in both cell lines, but displayed opposite effect on their migratory capability, leading to inhibition in B-CPAP and promotion in FTC-133 cells, by a MAPK-dependent mechanism. TGF-β1, TβRII and EGFR expressions were evaluated in benign and malignant thyroid tumors. Both positivity (51.7% and 60.0% and 80.0% in FA and PTC and FTC) and overexpression (60.0%, 77.7% and 75.0% in FA, PTC and FTC) of EGFR mRNA correlates with the aggressive tumor behavior. The moderate overexpression of TGF-β1 and TβRII mRNA in PTC tissues (61.5% and 62.5%, respectively), counteracted their high overexpression in FTC tissues (100% and 100%, respectively), while EGFR overexpression was similar in both carcinomas. Papillary carcinomas were positive to E-cadherin expression, while the follicular carcinomas lose E-cadherin staining. Our findings of TGF-β1/TβRII and EGFR overexpressions together with a loss of E-cadherin observed in human follicular thyroid carcinomas, and of increased migration ability MAPK-dependent after EGF/TGF-β1 treatments in the follicular thyroid carcinoma cell line, reinforced the hypothesis of a cross-talk between EGF and TGF-β1 systems in follicular thyroid carcinomas phenotype.     

Diagnostic value of qualitative and quantitative variables in thyroid lesions

Two hundred and thirty-three thyroid lesions were studied by fine needle aspiration (FNA) cytology using standard cytologic criteria available in the literature. These included 114 cases of nodular colloid goitre (NCG), 47 cases of Hashimoto's thyroiditis (HT), 12 follicular adenomas (FAd), five cases of subacute thyroiditis and three cases of thyrotoxicosis among the benign lesions. The malignant lesions seen were 30 cases of papillary carcinoma (PCa), 16 follicular carcinomas (FCa), three cases with double lesions, e.g. papillary carcinoma with coexisting NCG, and three of papillary carcinoma with HT. Emphasis was given to eight qualitative and quantitative (morphometric) variables in these various thyroid lesions. Cell measurements were done using a Visopan Lux projection microscope. The three qualitative variables included type of nuclear membrane (regular/irregular), type of nuclear chromatin and the presence or absence of conspicuous nucleoli. The quantitative variables studied were nuclear diameter, nuclear area, cytoplasmic diameter, cytoplasmic area & N/C ratio. Statistical analysis was performed in order to know whether the standard cytologic criteria used at FNA cytology in the literature (increased cellularity, microfollicles, increased N/C ratio, absence of significant haemosiderin-laden macrophages and scanty colloid) could differentiate a follicular adenoma from a follicular carcinoma. A statistical analysis was also performed to establish the utility of the qualitative and quantitative variables. The results showed that none of the standard cytologic criteria applied could differentiate follicular adenoma from a follicular carcinoma. With regard to qualitative variables, irregularity of nuclear membrane and presence of conspicuous nucleoli were most significant in papillary carcinoma, followed by follicular carcinoma, then by follicular adenoma; these features being hardly evident in nodular colloid goitre and Hashimoto's thyroiditis. A coarse nuclear chromatin was most significant in follicular carcinomas followed by follicular adenomas. It was less obvious in the benign conditions, but more prominent in Hashimoto's thyroiditis compared with a goitre. It was also not obvious in a papillary carcinoma. Of the quantitative variables, all measurements were greatest in PCa > FCa > FAd > NCG = HT. When differentiating follicular adenoma from follicular carcinoma the qualitative variables of significance were the presence or absence of nucleoli, the chromatin pattern and regularity/irregularity of nuclear membrane; the nuclear area was the most important feature among quantitative variables.     

Follicular variant of papillary thyroid carcinoma – a cytological study

The cytological diagnosis of classical papillary carcinoma is easily established based on the characteristic architectural and nuclear features. However, the follicular variant of papillary thyroid carcinoma(FVPTC) poses a diagnostic challenge. In this study we analysed the cytological features of 14 histopathologically proven cases of FVPTC. We inferred that a combination of architectural features such as follicles and syncytial clusters and nuclear features, viz grooves, pseudoinclusions and enlarged nuclei with fine chromatin, were helpful in establishing the diagnosis. It is hence suggested that based on the combination of the aforesaid features a diagnosis of FVPTC be offered whenever it is possible. This helps in patient management, obviating the need for a second surgical intervention.     

Necrotic Debris In Thyroid Aspirates: A Feature of Follicular Carcinoma of the Thyroid

Fine needle aspirates from 44 follicular thyroid tumours (30 adenomas, 14 carcinomas) have been studied. All aspirates contained neoplastic cells in follicular and trabecular arrangements. The individual tumour cells showed varying degrees of anisonucleosis and nuclear pleomorphism. Colloid was scanty or absent from all smears. Granular or filamentous necrotic material was observed in both biopsies and smears from one moderately and two poorly differentiated follicular carcinomas, but in none of the adenomas. This suggests that necrotic debris may be a feature of follicular carcinoma of the thyroid.     

Benign follicular thyroid lesions versus follicular variant of papillary carcinoma: differentiation by architectural pattern

Differentiation between benign and malignant follicular lesions is one of the difficult diagnostic areas in thyroid fine needle aspiration (FNA). Nuclear criteria are usually used to distinguish between them. In this study the microarchitectural pattern of common benign follicular lesions, namely nodular hyperplasia (NH) and follicular adenoma (FA) were analysed in comparison with those of follicular variant of papillary carcinoma (FVPC) in order to aid in their differentiation. The FNA smears of histologically proven cases of FVPC, NH and FA were reviewed and compared. The microarchitectural features of FVPC, NH and FA were described. Three cytological features--multi-layered rosettes, branching monolayered sheets and balls of thick pinkish colloid--were exclusively observed in FVPC. Hyperplastic papillae with intact follicles and colloid were frequently seen in NH, 83% and 100%, respectively. Albeit less frequently, they were also noted in FVPC, 25% and 75% of cases, respectively. These overlapping features make the distinction between FVPC and NH sometimes difficult; however, assessing the smears for the specific features of FVPC may help in their differentiation. None of the aforementioned microscopic findings with the exception of the seldom presence of colloid were documented in FA. The crowded clusters of follicular cells were seen both in FA and FVPC; however, they were complex and branching in the latter and round to oval in the former. Finally, smears with good recovery of material are indispensable for the identification of these helpful microarchitectural patterns.     

Role of Dicer1 in thyroid cell proliferation and differentiation

DICER1 plays a central role in the biogenesis of microRNAs and it is important for normal development. Altered microRNA expression and DICER1 dysregulation have been described in several types of tumors, including thyroid carcinomas. Recently, our group identified a new somatic mutation (c.5438A>G; E1813G) within DICER1 gene of an unknown function. Herein, we show that DICER1 is overexpressed, at mRNA level, in a significant-relative number of papillary (70%) and anaplastic (42%) thyroid carcinoma samples, whereas is drastically downregulated in all the analyzed human thyroid carcinoma cell lines (TPC-1, BCPAP, FRO and 8505c) in comparison with normal thyroid tissue samples. Conversely, DICER1 is downregulated, at protein level, in PTC in comparison with normal thyroid tissues. Our data also reveals that DICER1 overexpression positively regulates thyroid cell proliferation, whereas its silencing impairs thyroid cell differentiation. The expression of DICER1 gene mutation (c.5438A>G; E1813G) negatively affects the microRNA machinery and cell proliferation as well as upregulates DICER1 protein levels of thyroid cells but has no impact on thyroid differentiation. In conclusion, DICER1 protein is downregulated in papillary thyroid carcinomas and affects thyroid proliferation and differentiation, while DICER1 gene mutation (c.5438A>G; E1813G) compromises the DICER1 wild-type-mediated microRNA processing and cell proliferation.     

分子生物学法分析青少年甲状腺肿物临床病理及特点

探讨青少年甲状腺肿物的临床病理学特点,甲状腺癌的复发、转移和结节性甲状腺肿复发的可能相关因素。按WHO病理分型标准和国际抗癌联盟(UICC)TNM分期标准回顾性分析青少年甲状腺肿物124例及其中部分甲状腺癌和结节性甲状腺肿的随访资料。124例甲状腺肿物患者男女比例约为1 3,甲状腺癌39例(31.5%),其中乳头状癌35例,滤泡癌3例,髓样癌1例;甲状腺腺瘤59例(47.6%),结节性甲状腺肿11例(8.9%),结节性甲状腺肿伴腺瘤7例(5.6%),甲状腺炎5例(4%),甲状舌管囊肿3例(2.4%)。本组资料显示,青少年甲状腺癌以乳头状癌为主,其复发、转移与组织学亚型为弥漫硬化型及甲状腺包膜和其外软组织受侵状态相关。虽然常见淋巴结转移、肺转移以及局部侵犯周围软组织,但患者总体预后较好。结节性甲状腺肿的复发与病变弥漫位于双叶有关,而与患者性别、年龄和是否伴有乳头样及腺瘤样增生关系不密切。     

Galectin-3 is not useful in thyroid FNA

INTRODUCTION: Previous studies have suggested that galectin-3 immunohistochemistry may be useful in the fine needle aspiration (FNA) diagnosis of thyroid carcinoma as it has been reported to selectively stain carcinomas and not adenomas or goitres. METHODS: Fifty-one patients were included in a prospective study of galectin-3 in thyroid FNA; 88.2% were female and 11.8% male, mean age 53 years, range 25-87 years. Cell blocks were prepared and stained for galectin-3 if any cells were present in needle washings from the respective FNAs. RESULTS: Twelve of 51 (23.5%) of cell blocks contained epithelial cells. One benign and one inadequate FNA were negative for galectin-3 staining. One of five non-diagnostic FNA cases, a papillary carcinoma on final histology showed positive staining. Four follicular neoplasm/suspicious of carcinoma cases showed negative staining. One malignant FNA case, a papillary carcinoma showed positive staining with galectin-3 but three further carcinomas, two papillary and one follicular were galectin-3 negative. CONCLUSION: Galectin-3 immunohistochemistry does not appear to be a useful adjunct to diagnosis in thyroid FNA as it does not reliably distinguish malignant and benign lesions. Many thyroid aspirates are of low cellularity and are not suitable for cell block immunohistochemistry.     

Cytopathology of Follicular Tumours of the Thyroid With Clear Cell Change

A retrospective cytological study of nine follicular tumours of the thyroid with clear cell change was undertaken. In five clear cell adenomas and one moderately differentiated clear cell follicular carcinoma the epithelial cells occurred singly or in sheets and clusters; they sometimes assumed a trabecular or follicular pattern. The cells usually had pale diffusely vacuolated cytoplasm with ill-defined boundaries, a variable degree of anisonucleosis, nucleolar enlargement, and nuclear overlapping. Smears from a signet-ring cell adenoma contained in addition a few cells with large cytoplasmic vacuoles and compressed eccentric nuclei. In these cases a cytological diagnosis of 'follicular lesion' (or follicular neoplasia), clear cell type or signet-ring cell type, was given. A cytodiagnosis of 'carcinoma' was made only in the poorly differentiated follicular carcinoma-clear cell variant studied which showed unequivocal features of malignancy. Features suggestive of thyroid cyst, nodular goitre, Hashimoto's thyroiditis, and cell hyperactivity (marginal vacuoles, 'fire flare') were also found in the aspirated specimens of these cases of clear cell tumour of the thyroid.     

The number of nucleoli in benign and malignant thyroid lesions: a useful diagnostic sign in cytological preparations

The slides of fine needle aspiration cytology specimens from 99 cases of cold thyroid nodules with known histology were reviewed and the number of nucleoli per nucleus counted and correlated with the different histopathological groups. Significant differences were observed between benign and malignant thyroid lesions in the number of nucleoli in the cytological material. Lower values were present in nodular goitres and follicular adenomas compared to carcinomas. In benign lesions the majority of nuclei contained one nucleolus and nuclei with two, three or more nucleoli were less frequent than in follicular, papillary, medullary and anaplastic carcinomas. Only one case of follicular adenoma had cells containing three or more nucleoli compared to more than half the cases of follicular carcinoma.     

Type 2 chain glycosylation in thyroid carcinomas

Alterations of cell-surface carbohydrates are important for the metastatic behaviour of human carcinomas. Follicular and papillary thyroid carcinomas clinically show a very different metastatic pattern and represent a good model for studies of the metastatic process. We examined the expression of various Le^x-related carbohydrates in 30 primary papillary, 20 primary follicular and 15 primary anaplastic thyroid carcinomas by means of immunohistochemistry. Six metastases from papillary and five from follicular carcinomas were also examined. Morphologically normal thyroid epithelium did not express any of the type 2 carbohydrates. Papillary carcinomas were immunoreactive for several type 2 carbohydrates, including sialyl-Lewis X, in contrast to follicular and anaplastic carcinomas. The metastases showed no significant differences in expression of carbohydrates compared with the primary tumours. We hypothesize that the up-regulation of sialyl-Lewis X and some other related carbohydrates in papillary carcinomas is of importance for the clinical behaviour of these tumours.     

Molecular pathology and thyroid FNA

This review summarises molecular pathological techniques applicable to thyroid FNA. The molecular pathology of thyroid tumours is now fairly well understood. Molecular methods may be used as a rule‐in test for diagnosis of malignancy in thyroid nodules, eg BRAF V600E point mutation, use of a seven‐gene mutational panel (BRAF V600E, RAS genes, RET/PTC or PAX8/PPARG rearrangement), or as a comprehensive multigene next‐generation sequencing panel, eg ThyroSeq v2. Molecular methods can also be applied as rule‐out tests for malignancy in thyroid nodules, eg Afirma or ThyroSeq v2 or as markers of prognosis, eg TERT promoter mutation or other gene mutations including BRAF V600E, TP53 and AKT1, and as tests for newly defined tumour entities such as non‐invasive follicular thyroid neoplasm with papillary like nuclei, or as a molecular marker(s) for targeted therapies. This review describes practical examples of molecular techniques as applied to thyroid FNA in routine clinical practice and the value of molecular diagnostics in thyroid FNA. It describes the range of molecular abnormalities identified in thyroid nodules and thyroid cancers with some practical applications of molecular methods to diagnosis and prognosis of thyroid nodules and thyroid cancer.     

乳头状甲状腺癌中线粒体DNA突变的研究

该文探究了线粒体DNA(mtDNA)突变与甲状腺癌的发生发展的相关性,评估了mtDNA拷贝数对甲状腺癌的诊断价值。根据对结节性甲状腺肿、滤泡状甲状腺腺瘤和乳头状甲状腺癌3组病人的mtDNA全基因测序和单倍型分型结果,统计3组病人mtDNA突变率及单倍型的差异,分析乳头状甲状腺癌病人的mtDNA突变率与临床资料的联系,最后通过荧光定量PCR检测3组病人的组织和血液样本中mtDNA的拷贝数。结果显示,乳头状甲状腺癌患者mtDNA的复合体I亚基编码区和tRNA编码区的突变率明显高于结节性甲状腺肿,在乳头状甲状腺癌患者中线粒体单体型M相对于单体型N有更低的淋巴结转移率,荧光定量PCR结果显示,甲状腺腺瘤和甲状腺癌组织中的mtDNA拷贝数明显高于结节性甲状腺肿,而在血液标本中,两者的mtDNA拷贝数均低于结节性甲状腺肿。这些结果表明,mtDNA拷贝数的变化和复合体I亚基编码区的突变可能作为甲状腺癌诊断的生物指标,而线粒体单体型N可能可以作为乳头状甲状腺癌恶性变化的预警指标。     

Co-expression of matriptase and N-acetylglucosaminyltransferase V in thyroid cancer tissues--its possible role in prolonged stability in vivo by aberrant glycosylation

UDP-N-acetylglucosamine:alpha-mannoside beta-1,6-N-acetylglucosaminyltransferase (GnT-V) catalyzes the formation of beta-1-6 GlcNAc branches on asparagine-linked oligosaccharides, which is directly linked to tumorigenesis. Our recent studies indicate that the secretion of matriptase from cancer cells is increased via the action of GnT-V, as evidenced by the fact that matriptase-bearing beta-1-6 GlcNAc branching is dramatically inhibited. In this study, we report on an investigation of the expression of GnT-V and matriptase in thyroid neoplasm tissues to determine the clinical significance on the co-expression of these two proteins in thyroid cancer. Although neither GnT-V nor matriptase was expressed in normal thyroid tissue, positive staining for matriptase and GnT-V was observed in 52/68 and 66/68 cases of papillary carcinoma, 3/23 and 10/23 cases of follicular carcinoma, 5/13 and 9/13 cases of follicular adenoma, and 11/28 and 6/28 cases of anaplastic carcinoma, respectively. Immunohistochemistry, as well as western blotting, showed that the expression of matriptase paralleled the expression to GnT-V. However, the expression of matriptase mRNA was not correlated with its protein levels, suggesting that the enhancement in matriptase expression could be regulated by a posttranslational modification such as glycosylation through GnT-V-mediated glycosylation. In papillary carcinoma, the levels of expression of both GnT-V and matriptase were significantly higher in tumors 1 cm or less in size (microcarcinoma) and in those without poorly differentiated lesions, and the two proteins were significantly correlated. In contrast, the prognosis of thyroid carcinoma after surgery was neither correlated with the expression GnT-V nor matriptase, because the levels of their expression were quite low in anaplastic (undifferentiated) carcinomas. These results suggest that prolonged stabilization of matriptase is stabilized by GnT-V-mediated glycosylation in vivo, thus extending its halftime and permitting it to play role in the early phases of papillary carcinoma, but not in its later phase progression.     

Dipeptidyl peptidase IV expression in thyroid cytology: retrospective histologically confirmed study

Fine needle aspiration cytology (FNAC) of the thyroid gland is a well-established method. However, it has inherent limitations, especially in the diagnosis of follicular and oncocytic tumours and in distinguishing between nuclear atypia in colloid goitre with regressive changes and cystic papillary carcinoma. The aim of our study was to evaluate dipeptidyl peptidase IV (DPP IV) as a marker of malignancy in FNAC. We tested 254 thyroid specimens (intraoperative imprint smears) for DPP IV. The sensitivity was 71%, the specificity was 96%, and the diagnostic accuracy was 93%, respectively, with a threshold of 50% of positive cells. To the best of our knowledge it is the largest histologically confirmed study reported in the literature. We suggest the assessment of DPP IV as an adjunct diagnostic marker of malignancy in thyroid specimens suspicious of papillary carcinoma. However, the value of the marker in follicular lesions is very limited.