Updates in head and neck cytopathology: Insights from European Congress of Pathology Short Course.

Cytological specimens play a pivotal role in head and neck nodule/mass work up and diagnoses. The specimens´ importance has grown with the onset of personalized medicine and the routine use of molecular markers in the diagnostic work up. The Updates in Head and Neck Cytopathology Short Course ran during the 35th European Congress of Pathology held in Dublin, Ireland, in 2023 and brought together experts in cytopathology, pathology, and related fields to share their expertise and experience in the field of head and neck cytopathology and its future directions. Topics such as a one-stop clinic, the Milan System for Reporting Salivary Gland Cytopathology, next generation sequencing, and human papilloma virus detection in the head and neck area were covered during the short course. These topics are briefly summarized in the present review.

Primary HPV screening for cervical cancer: Results after two screening rounds in a regional screening program in Finland.

INTRODUCTION: Since 2012, cervical cancer screening has been conducted with a primary high-risk human papillomavirus (hrHPV) test and conventional cytology triage in the city of Tampere, Finland. The women who were screened with the hrHPV test in 2012 were invited to participate in the second screening round in 2017. The aim of the present report was to compare the number of colposcopy referrals and the number of histological high-grade squamous intraepithelial lesion (HSIL)+ (cervical intraepithelial neoplasia [CIN2+]) lesions between the first and second screening rounds of women of a specific age group who were screened twice with the hrHPV test. MATERIAL AND METHODS: The primary hrHPV test used was the RealTime hrHPV PCR assay by Abbott. Women with a positive hrHPV test and cytology triage equal to or worse than low-grade squamous intraepithelial lesion or atypical glandular cells, favor neoplasia, were directly referred to colposcopy, whereas hrHPV-positive women with a negative or equivocal cytology triage were re-screened after approximately 12-16 months. hrHPV-negative women were scheduled for re-screening after 5 years. The present report focuses on the cohort of women who were screened twice with the hrHPV test, who were 35-55 years old in 2012, and 40-60 years old in 2017. RESULTS: In all, 8076 women were invited for HPV screening in 2012 and 8331 women were invited for the second round 5 years later, with attendance rates of 70% and 71%, respectively. Of the women who were screened in 2012, 4571 (69%) belonged to the 35- to 55-year age cohort. In 2017, 4807 (73%) of the women aged 40-60 years participated in the screening. In this cohort, 185 (4.0%) colposcopies were performed in the first screening round, compared with 139 (2.9%) in the second round, and the colposcopy rate was 29% smaller in the second round (P = .002). The number of histological HSIL+ cases was 38 (0.8%) during the first screening round and 29 (0.6%) during the second round (P = .220). CONCLUSIONS: In the setting of routine organized cervical cancer screening, the initially high colposcopy rate associated with primary HPV screening seems to level off at the second screening round in women who were screened twice with an hrHPV test.

The role of fine-needle aspiration biopsy (FNAB) in the diagnostic management of parotid gland masses with emphasis on potential pitfalls.

PURPOSE: The treatment strategy of parotid gland tumours depends mainly on the histopathological type of the lesion. Fine-needle aspiration biopsy (FNAB) is recommended in preoperative diagnostics. The aim of the study was to evaluate the FNAB standing in the diagnostic algorithm of parotid gland lesions and to correlate FNAB results in relation to the definitive histopathological diagnosis. MATERIAL AND METHODS: The retrospective analyses of 651 examined and consequently surgically treated parotid gland lesions at the Department of Otorhinolaryngology and Head and Neck Surgery, 1st Faculty of Medicine, Charles University in Prague between 2006 and 2016 were used. Preoperative cytological results were consequently evaluated in relation to the definitive histopathological diagnosis. RESULTS: The cohort consisted of 367 women and 284 men (average age 58 years). FNAB was diagnostic in 604 (92.8%) patients and non-diagnostic in 47 (7.2%) patients. The result of FNAB was positive (suspicious for malignant tumour) in 89 (14.7%) patients and negative (benign) in 515 (85.3%) patients. Sensitivity of the examination was 80.00%, specificity was 93.82%, PPV 62.92%, NPV 97.28%, and LR + and LR- were 12.95 and 0.21, respectively, with an accuracy of 92.22%. CONCLUSION: Our results confirm the significant role of FNAB in the diagnostic algorithm of parotid gland lesions.

Implementation of HPV-based cervical cancer screening in an organised regional screening programme: 3 years of experience.

OBJECTIVE: The aim of this study was to evaluate the performance of human papillomavirus (HPV)-based screening in the framework of an organised cervical cancer screening programme. METHODS: A total of 46 708 women aged 35-60 years invited to the regional cervical cancer screening programme from 1 January 2012, to 31 December 2014, were enrolled. Overall, 17 770 women were screened by the Abbot RealTime hrHPV test with cytology triage and 15 605 were screened by conventional (Papanicolaou, Pap) cytology. In both groups, women with at least low-grade squamous intraepithelial lesions were referred directly for colposcopy, whereas HPV-positive women with borderline or normal cytology were invited to intensified screening in the following year. In the Pap group, the indication for intensified follow-up was borderline cytology. RESULTS: The attendance rate was similar in the HPV and Pap groups (72% and 71%, respectively). Overall, 6.0% of women in the HPV group vs 6.4% in the Pap group were referred to intensified follow-up (relative risk 0.94, 95% confidence interval [CI]: 0.87-1.03). At the index screening years, the relative sensitivity of the HPV test with cytology triage vs conventional screening was 1.64 (95% CI: 1.05-2.55) for CIN2+ and 2.06 (95% CI: 1.17-3.41) for CIN3+. The specificity of the hrHPV test with cytology triage for CIN2+ and CIN3+ was equal to that of the Pap screening (99.2% vs 99.2% for CIN2+ and 99.1% vs 99.1% for CIN3+). CONCLUSIONS: Due to its high sensitivity and specificity, primary hrHPV testing with cytology triage seems to be acceptable for cervical cancer screening in an organised setting.

Carbonic anhydrase IX deposits are associated with increased ascending aortic dilatation.

OBJECTIVES: Carbonic anhydrase IX (CA IX) expression is induced by local hypoxia. We studied whether CA IX deposits associate with ascending aortic dilatation. DESIGN: Aortic wall histology, CA IX expression, presence of leukocytes, plasma cells, macrophages, endothelial cells, smooth muscle cells, cell proliferation, elastin and collagen were studied in histological specimens collected from 30 patients who underwent surgery for ascending aorta. The samples were grouped according to presence of CA IX deposits. RESULTS: Twenty out of 30 patients had CA IX-positive deposits within the adventitia, whereas 10 specimens remained negative. Adventitial inflammation was increased in CA IX-positive samples as compared with CA IX-negative ones (p < 0.01). The mean diameter of the ascending aorta at the sinotubular junction increased significantly in patients with CA IX-positive staining as compared with CA IX-negative cases (63 ± 3 vs 53 ± 2 mm, p < 0.02). Receiver operating characteristic curve analysis confirmed the association of CA IX positivity with increased ascending aortic dilatation (AUC 0.766; S.E. 0.090; p = 0.020; 95% C.I. 0.590-0.941). CONCLUSIONS: Positive CA IX staining in certain aortic specimens suggests that increased CA activity may contribute to ascending aortic dilatation.

Human papillomavirus test with cytology triage in organized screening for cervical cancer.

INTRODUCTION: In randomized studies, testing for high-risk (HR) human papillomavirus (hrHPV) has been more sensitive than conventional cytology in detecting cervical intraepithelial neoplasia (CIN). The aim of this study was to evaluate the performance of HPV testing in the setting of an organized routine screening program. MATERIAL AND METHODS: Since 2012, 35- to 60-year-old women living in the city of Tampere have been screened with the Abbott RealTime hrHPV test. HPV-negative women are referred to the next screening round in five years. HPV-positive women are triaged with conventional cytology, and women with at least low-grade squamous intraepithelial lesion (LSIL+ ) are referred to colposcopy. The remaining HPV-positive women are referred for re-testing after 12 months, and then all HPV-positive women are referred to colposcopy. The data from the last cohort with cytological screening (screened in 2011) is presented for comparison. RESULTS: A total 5637 (70%) women attended the first round of HPV screening, and 369 were HPV-positive. Of them, 54 women LSIL+ were referred to colposcopy, resulting in 16 CIN2+ lesions found. Of the remaining HPV-positive women, 66% were still positive one year later, and were referred to colposcopy, with 18 additional CIN2+ lesions found. The attendance rate to the last round of cytological screening was 71% (5814 women). Sixty-four women with LSIL+ cytology were referred to colposcopy, and 11 CIN2+ lesions were found. Of the 777 women with borderline cytology and scheduled for reflex screening in the following year, 109 (19%) had ASC-US+ , and 57 underwent colposcopy, resulting in six additional CIN2+ lesions found. The total detection rate of CIN2+ was significantly higher in the HPV-screened cohort (6.0/1000 vs. 2.9/1000, p = 0.015). However, the total colposcopy rate was 4% vs. 2%, respectively (p < 0.001). CONCLUSION: Human papillomavirus testing also seems to be more sensitive than cytology in detecting CIN2+ lesions in the setting of a routine organized screening program, besides in the context of randomized trials. The problem of an increased colposcopy rate needs to be addressed in the future.

VEGF receptor 2/-3 heterodimers detected in situ by proximity ligation on angiogenic sprouts.

The vascular endothelial growth factors VEGFA and VEGFC are crucial regulators of vascular development. They exert their effects by dimerization and activation of the cognate receptors VEGFR2 and VEGFR3. Here, we have used in situ proximity ligation to detect receptor complexes in intact endothelial cells. We show that both VEGFA and VEGFC potently induce formation of VEGFR2/-3 heterodimers. Receptor heterodimers were found in both developing blood vessels and immature lymphatic structures in embryoid bodies. We present evidence that heterodimers frequently localize to tip cell filopodia. Interestingly, in the presence of VEGFC, heterodimers were enriched in the leading tip cells as compared with trailing stalk cells of growing sprouts. Neutralization of VEGFR3 to prevent heterodimer formation in response to VEGFA decreased the extent of angiogenic sprouting. We conclude that VEGFR2/-3 heterodimers on angiogenic sprouts induced by VEGFA or VEGFC may serve to positively regulate angiogenic sprouting.

Recurrent thyroid cancers have more peritumoural lymphatic vasculature than nonrecurrent thyroid cancers.

BACKGROUND: The goal of the study was to evaluate angiogenesis and lymphangiogenesis in differentiated thyroid cancer and recurrences. METHODS: Twenty-seven patients with recurrent differentiated thyroid cancer (20 papillary and seven follicular thyroid carcinomas) and 24 nonrecurrent thyroid cancers were included in this study. Additionally, 24 thyroid adenomas were included as benign controls. All thyroid cancer recurrences were operatively managed, and local recurrences in cervical lymph nodes or cervical soft tissue were histologically confirmed. Altogether, a total of 108 samples were evaluated using CD31 and D2-40 immunohistochemical staining and microscopy. RESULTS: As measured in primary tumours, the median density of CD31-positive vascular structures was 327 vessels (v)/mm(2) for recurrent cancers, 362 v/mm(2) for nonrecurrent cancers and 484 v/mm(2) for thyroid adenomas (P = 0·017). Among the subgroups, the lowest median vascular density of 316 v/mm(2) was found in recurrent papillary cancers and the highest vascular density of 604 v/mm(2) was observed in nonrecurrent follicular cancers (P = 0·018). The median density of D2-40-positive peritumoural lymphatic vessels was 101/mm(2) in recurrent cancers, 56·1/mm(2) in nonrecurrent cancers and 53·9/mm(2) for adenomas (P = 0·015). In the subgroups, peritumoural lymphatic vascular density was 102 v/mm(2) in recurrent papillary cancers and 56·0 v/mm(2) in nonrecurrent papillary cancers (P = 0·044). CONCLUSIONS: Recurrent thyroid cancers expressed less intratumoural microvessels than thyroid adenomas. A high density of peritumoural lymphatic vessels was found in recurrent papillary cancers. High blood vessel density may be a marker for less aggressive tumours, while high peritumoural lymphatic vasculature is a marker for more aggressive and recurrence-prone tumours.

[Up-to-date experience with the international classification system Bethesda 2010 for thyroid fine-needle aspirate: a review]. / Prehled dosavadních zkuseností s mezinárodní klasifikací tenkojehlové aspiracní cytologie stítné zlázy Bethesda 2010.

The Bethesda System for Reporting Thyroid Cytopathology (BSRTC) was introduced in thyroid fine needle aspiration cytology (FNAC) in 2010. A six-tier system is generally accepted. Bethesda categories include morphologic description, risk of malignancy and follow-up suggestions in each group. The system has its advantages and disadvantages, that are discussed. The most problematic are the categories of "Atypia of undetermined significance" or "Follicular lesion of undetermined significance" (AUS/FLUS). The group is heterogenous and overused thus far. The possibilities of its improvement are discussed. The Bethesda system does not include any prognostic and predictive markers. However, they represent the promising direction in the improved version of the BSRTC. Novel molecular methods and alternative techniques such as core needle biopsy are briefly discussed.

The World Health Organization Reporting System for Lung Cytopathology-A Review of the First Edition.

The World Health Organization Reporting System for Lung Cytopathology is the first international system that was developed to standardize the reporting of lung cytopathology specimens across all settings of cytopathology practice. The system is composed of five diagnostic categories, which apply to all lung cytopathology specimen types. Each category contains cytomorphologic criteria, an estimated risk of malignancy, and clinical management recommendations. International uniformity in the reporting of lung cytopathology will refine the communication between cytopathologists and clinicians and ultimately improve patient care. Furthermore, standardizing the cytomorphologic criteria for each lesion will improve reproducibility among cytopathologists and highlight areas in lung cytopathology that require further research. The system also provides best practice recommendations for the selection of ancillary tests to aid in the diagnosis of each lesion, or group of lesions, keeping in mind that resources will vary across different practice settings. The goal of this review is to summarize the cytomorphologic criteria, potential diagnostic pitfalls, ancillary testing, estimated risk of malignancy, and clinical management recommendations for each diagnostic category.

Aortic elastic fiber degeneration during acute type a aortic dissection and reverse aortic remodeling.

BACKGROUND: Progression of proximal or distal aortic dilatation is defined as reverse aortic remodeling after surgery for acute type A aortic dissection (ATAAD) that may be dependent on aortic wall degeneration. METHODS: We investigated whether aortic wall degeneration is associated with reverse aortic remodeling leading to aortic reoperation after surgery for ATAAD. Altogether, 141 consecutive patients undergoing surgery for ATAAD at Tampere were evaluated. The resected ascending aortic wall at surgery was processed for 42 degenerative, atherosclerotic and inflammatory histological variables. Patients undergoing aortic reoperations (Redos) were compared with those without aortic reoperations (Controls) during a mean 4.9-year follow-up. RESULTS: Redos were younger than Controls (56 and 66 years, respectively, P < 0.001), and had less frequently previous cardiac surgery prior to ATAAD. Initial surgery encompassed replacement of the ascending aorta in the majority. There were 21 Redos in which one patient died during follow-up as compared with 51 deaths in Controls (log Rank P = 0.002). Histology of the aortic wall revealed increased elastic fiber fragmentation, loss, and disorganization in Redos as compared with Controls (2.1 ± 0.5 vs. 1.9 ± 0.5, Point score unit (PSU), P = 0.043 and 1.7 ± 0.8 vs. 1.2 ± 0.8, PSU, P = 0.016, respectively). Moderate atherosclerosis occurred less often in Redos vs. Controls (9.5% vs. 33%, PSU, P = 0.037, respectively). CONCLUSIONS: According to this exploratory study, histopathology reveals distinctive aortic wall degeneration during ATAAD. Reverse aortic remodeling after ATAAD is associated with the presence of ascending aortic wall elastic fiber fragmentation, loss and disorganization during ATAAD.

How the Milan System for Reporting Salivary Gland Cytopathology works in cytopathology practice: Meta-analysis of prospective studies and comparison with retrospective studies.

BACKGROUND: The Milan System for Reporting Salivary Gland Cytopathology (MSRSGC) is widely accepted and endorsed by professional societies. Although several studies focusing on the MSRSGC have been published, few have been prospective studies. The objective of this study was to evaluate the effectiveness of the MSRSGC in cytopathology practice. METHODS: A comprehensive literature search was conducted to identify all prospective studies on the MSRSGC. The risk of malignancy (ROM), risk of neoplasm, and diagnostic accuracy for each diagnostic category were calculated. Data were tabulated in Microsoft Excel, and analyses were performed with the Open Meta-Analyst program. RESULTS: Seven prospective and seven retrospective studies were identified. The total number of fine-needle aspirations (FNAs) was 1587 in the prospective studies and 1764 in the retrospective studies. The ROM values for the nondiagnostic, nonneoplastic, atypia of undetermined significance, benign neoplasm, salivary gland neoplasm of uncertain malignant potential, suspicious for malignancy, and malignant categories in prospective versus retrospective studies were 21.0% versus 26.6%, 9.4% versus 8.1%, 34.9% versus 39.6%, 2.4% versus 2.1%, 36.6% versus 31.2%, 86.0% versus 66.0%, and 97.0% versus 96.7%, respectively. Sensitivities, specificities, and diagnostic odds ratios were 83.1% (95% confidence interval [CI], 71.1%-90.8%) versus 89.1% (95% CI, 83.6%-92.9%), 98.4% (95% CI, 96.6%-99.3%) versus 94.9% (95% CI, 91.9%-96.9%), and 310.7 (95% CI, 121.2-796.6) versus 218.8 (95% CI, 107.3-438.1). CONCLUSIONS: This meta-analysis indicated that the MSRSGC works well in FNA cytopathology practice and improves diagnostic accuracy in all diagnostic categories. The ROMs of prospective studies were in concordance with the MSRSGC reference values.

Insufficient endobronchial ultrasound-guided transbronchial needle aspiration specimens. When and why? The analysis of criteria and reasons behind the insufficient specimens.

BACKGROUND: The classification terminology systems for pulmonary cytology specimens have recently emerged. Inadequate samples, classified as "nondiagnostic," raise challenges in determining the threshold of cell numbers and the risk of malignancy (ROM). METHODS: The study retrospectively reviewed 248 endobronchial ultrasound-guided transbronchial needle aspiration (EBUS-TBNA) samples: 46 insufficient samples, 60 low cellularity samples, and 142 adequate samples. Characteristics as cellularity, number of benign and malignant cells, and background features were assessed. Receiver operating characteristic curve analysis was performed to establish cell sufficiency thresholds for the diagnosis. RESULTS: Out of the 248 samples analyzed, 108 were classified as benign, 94 as malignant, and 46 as insufficient. The study found that the cellularity thresholds for diagnosis in cell blocks and cytological samples were ≥50 cells and ≥100 cells, respectively. The thresholds for tumor cell counts were ≥1 - 10 cells for both types of cells, respectively. Considerably, some low cellularity samples were initially classified as insufficient despite meeting the diagnostic thresholds upon revision. The ROM varied across sample categories, with insufficient samples having a ROM of 10.9%, benign samples 15.7%, suspicious samples 92.0%, and malignant samples 100%. CONCLUSION: Insufficient EBUS-TBNA samples raise challenges in diagnosis and management. This study identified the root cause of insufficient samples, including factors related to humans, diagnostic methods, sampling, and laboratory processing. By understanding the root causes, diagnostic recommendations can be developed to improve the diagnostic process. The findings emphasize the importance of standardized classification and terminology systems for clear communication among healthcare professionals and institutions, ultimately improving patient care and enabling quality assurance measures.

Histopathology reveals concealed aortic valve inflammation.

BACKGROUND: The extent of aortic valve inflammation in patients undergoing aortic valve replacement (AVR) is unsettled. The significance of aortic valve histopathology in patients undergoing AVR is undetermined. METHODS: A total of 145 resected aortic valves of consecutive patients undergoing surgery for a local aortic valve disease with or without ascending aorta were investigated for histopathology. The extent of inflammation and degeneration were investigated. Unadjusted survival was evaluated by Kaplan-Meier analysis. Median follow-up was 2.7 years (interquartile range 1.5-3.9). RESULTS: Mean patient age was 69 (SD 11) years. Though endocarditis was apparent in only six patients preoperatively, severe aortic valve inflammation was diagnosed histologically in 32 patients of whom 12 patients had acute, subacute or chronic endocarditis. Despite complete aortic valve resection, survival was decreased in patients with severe aortic valve inflammation as opposed to those without (log rank, P = 0.044), even after exclusion of patients with endocarditis, emergency and aortic surgery. CONCLUSIONS: Aortic valve tissue analysis reveals severe inflammation that may require postoperative treatment. The association of severe but local aortic valve inflammation with patient outcome after aortic valve surgery merits further investigation.

Segmental arterial mediolysis leading to spontaneous rupture of splenic artery and fatal hemorrhage in pregnancy.

We report an unexpected death of a 22-year-old primigravida who was admitted to the hospital with sudden abdominal pain two days before a scheduled delivery. During an emergency caesarean section due to intrauterine asphyxia, intraabdominal bleeding was observed with no apparent source of bleeding. Newly formed blood clots in the subdiaphragmatic space and arterial bleeding near the splenic hilum required a surgery on the next day. Hemorrhagic shock led to multiple organ failure on the fourth day of admission. The autopsy revealed ruptured splenic artery at the pancreatic tail and near the splenic hilum. Microscopically, different stages of segmental arterial mediolysis were observed in partially thinned and aneurysmatic artery.

Detailed study of collagen, vasculature, and innervation in the human cardiac conduction system.

BACKGROUND: The cardiac conduction system (CCS) creates and propagates electrical signals generating the heartbeat. This study aimed to assess the collagen content, vasculature, and innervation in the human sinoatrial and atrioventricular CCS, and surrounding tissue. MATERIALS AND METHODS: Ten sinoatrial and 17 atrioventricular CCS samples were collected from 17 adult human autopsied hearts. Masson trichrome stain was used to examine collagen, cardiomyocytes, and fat proportions. Immunohistochemically, vessels and lymphatics were studied by CD31 (pan-endothelial marker) and D2-40 (lymphatic endothelium marker) antibodies. General nerve densities were assessed by S100, while sympathetic nerves were studied using tyrosine hydroxylase, parasympathetic nerves with choline acetyltransferase, and GAP43 (neural growth marker) antibodies looked at these components. All components were quantified with QuPath software (Queens University, Belfast, Northern Ireland). RESULTS: Interstitial collagen was more than two times higher in the sinoatrial vs. atrioventricular CCS (55% vs. 22%). The fat content was 6.3% in the sinoatrial CCS and 6.5% in the atrioventricular CCS. The lymphatic vessel density was increased in the sinoatrial and atrioventricular CCS compared to the surrounding tissue and was lower in the sinoatrial vs. atrioventricular CCS (P=.043). The overall vasculature density did not differ between the SA and AV CCS. The overall innervation and neural growth densities were significantly increased in the CCS compared to the surrounding tissue. The overall innervation was higher in the atrial vs. ventricular CCS (P=.018). The neural growth was higher in the atrial vs. ventricular CCS (P=.018). The sympathetic neural supply was dominant in all the studied regions with the highest density in the sinoatrial CCS. CONCLUSIONS: Our results provide new insights into the unique morphology of the human CCS collagen, fat, vasculature, and innervation. A deeper understanding of the CCS anatomical components and morphologic substrates' role will help in elucidating the causes of cardiac arrhythmias and provide a basis for further therapeutic interventions.

The autonomic nerves around the vein of Marshall: a postmortem study with clinical implications.

This study aims to analyze the vein of Marshall (VOM) in human autopsy hearts and its correlation with clinical data to elucidate the morphological substrates of atrial fibrillation (AF) and other cardiac diseases. Twenty-three adult autopsy hearts were studied, assessing autonomic nerves by immunohistochemistry with tyrosine hydroxylase (sympathetic nerves), choline acetyltransferase (parasympathetic nerves), growth-associated protein 43 (neural growth), and S100 (general neural marker) antibodies. Interstitial fibrosis was assessed by Masson trichrome staining. Measurements were conducted via morphometric software. The results were correlated with clinical data. Sympathetic innervation was abundant in all VOM-adjacent regions. Subjects with a history of AF, cardiovascular cause of death, and histologically verified myocardial infarction had increased sympathetic innervation and neural growth around the VOM at the mitral isthmus. Interstitial fibrosis increased with age and heart weight was associated with AF and cardiovascular cause of death. This study increases our understanding of the cardiac autonomic innervation in the VOM area in various diseases, offering implications for the development of new therapeutic approaches targeting the autonomic nervous system.

Cell block practices in European cytopathology laboratories.

BACKGROUND: There are numerous methods and procedures described for the preparation of cell blocks (CBs) from cytological samples. The objective of this study was to determine current practices and issues with CBs in European laboratories. METHODS: A link to an online survey, with 11 questions about CB practices, was distributed to cytology laboratories via participants of United Kingdom National External Quality Assurance Service for Cellular Pathology Techniques and national representatives in the European Federation of Cytology Societies. RESULTS: A total of 402 laboratories responded completely (337/402, 84%) or partially (65/402, 16%) to the survey by February 4, 2022. The most common CB practice is embedding cell pellets using plasma and thrombin (23.3%), agar (17.1%), Shandon/Epredia Cytoblock (11.4%), HistoGel (7.9%), and Cellient (3.5%). Other methods such as CytoFoam, albumin, gelatin, Cytomatrix, and collodion bags are rarely used (1.0%, 0.7%, 0.7%, 0.3%, and 0.2%, respectively). CBs are also prepared from naturally occurring clots or tissue fragments (29.5%) and cells scraped from unstained or prestained smears (4.4%). The most frequent issues with the CBs in a daily cytology practice are low cellularity (248/402, 62%) and dispersed cells (89/402, 22%), regardless of the CBs preparation method or how the samples for embedding were selected. CONCLUSIONS: There is a great variability in CB practices in European laboratories with low cellular CBs as the main issue. Additional studies are mandatory to evaluate and improve performance and cellular yield of CBs.

BRAF mutation, selected miRNAs and genes expression in primary papillary thyroid carcinomas and local lymph node metastases.

Mutations in cancer-related genes are now known to be accompanied by epigenetic events in carcinogenesis by modification of the regulatory pathways and expression of genes involved in the pathobiology. Such cancer-related mutations, miRNAs and gene expression may be promising molecular markers of the most common papillary thyroid carcinoma (PTC). However, there are limited data on their relationships. The aim of this study was to analyse the interactions between BRAF mutations, selected microRNAs (miR-21, miR-34a, miR-146b, and miR-9) and the expression of selected genes (LGALS3, NKX2-1, TACSTD2, TPO) involved in the pathogenesis of PTC. The study cohort included 60 primary papillary thyroid carcinomas (PTC) that were classified as classical (PTC/C; n=50) and invasive follicular variant (PTC/F; n=10), and 40 paired lymph node metastases (LNM). BRAF mutation status in primary and recurrent/persistent papillary thyroid carcinomas was determined. The mutation results were compared both between primary and metastatic cancer tissue, and between BRAF mutation status and selected genes and miRNA expression in primary PTC. Furthermore, miRNAs and gene expression were compared between primary PTCs and non-neoplastic tissue, and local lymph node metastatic tumor, respectively. All studied markers showed several significant mutual interactions and contexts. In conclusion, to the best our knowledge, this is the first integrated study of BRAF mutational status, the expression levels of mRNAs of selected genes and miRNAs in primary PTC, and paired LNM.