The Simultaneous Use of Bladder Epicheck® and Urinary Cytology Can Improve the Sensitivity and Specificity of Diagnostic Follow-Up of Urothelial Lesions: Up-to-Date Data from a Multi-Institutional Cohort.

Background/Objectives: Bladder cancer is a prevalent urinary system malignancy and urinary cytology is widely used for its screening and follow-up. A novel diagnostic tool called Bladder Epicheck® (BE) is increasingly being used for monitoring the recurrence of non-muscle-invasive bladder cancer (NMIBC). The simultaneous use of BE and urinary cytology can increase the diagnostic performances in the follow-up of bladder neoplasms. Methods: In this multicenter study, we retrospectively evaluated the data of 322 patients in follow-up for a high-grade bladder carcinoma over a six-year period (from January 2018 to March 2024). The diagnostic performances of both cytology and BE and their combination were calculated using histology as gold standard. Results: Recurrences were diagnosed as high-grade urothelial carcinoma NMIBC in 18 cases, low-grade papillary NMIBC in 8 cases, and carcinoma in situ (CIS) in 4 cases. Cytological analysis correctly identified 26 out of 30 carcinomas, while 286 were correctly diagnosed as negative results. BE correctly identified 25 out of 30 carcinomas, 285 were correctly diagnosed as negative results. The combination of BE and urinary cytology correctly identified 29 out of 30 carcinomas, while 289 were correctly diagnosed as negative results. Conclusions: The combination of BE and cytology could be the most effective approach for follow-up diagnosis in patients with high-grade NMIBC, reducing unnecessary invasive procedures.

Immunohistochemical Profile of p62/SQSTM1/Sequestosome-1 in Human Low- and High-Grade Intracranial Meningiomas.

Among autophagic-related proteins, p62/SQSTM1/Sequestosome-1 represents a relevant actor in cellular proliferation and neoplastic growth. Although, recently, p62 expression has been analyzed in different neurodegenerative and glial neoplastic diseases, no available information have been reported in meningiomas, which have an high epidemiological relevance being the second most common category of intracranial tumors after gliomas. Generally meningiomas have a benign behavior, but their recurrence is not uncommon mainly when atypical or anaplastic varieties occur. However, intranuclear vacuoles have been ultrastructurally observed in meningiomas, and they were labelled by p62 antibodies. Therefore, in the present study, we have investigated p62 immunohistochemical pattern in a cohort of 133 cases representative of low- and high-grade meningiomas, to verify if p62 expression may be related to clinicopathological data, thus achieving a potential prognostic role. The p62 immunoexpression was frequently found in the nucleus and cytoplasm of neoplastic elements, and utilizing an intensity-distribution score, 55 (41.3%) cases were considered as high expressors while 78 (58.7%) cases were instead recorded as low expressors. Fifteen cases exhibited recurrences of the disease, 14 of which were codified as high expressors. Moreover, a direct relationship between p62 and Mib-1 immunoexpression as well as between p62 and neoplastic grade have been documented. Finally, we suggest that impaired autophagic flux with an increase in p62 expression may be involved in the activation of NRF2 also contributing in the development of recurrence in meningioma patients.

Case Report: Plummer's adenoma in Prader-Willi syndrome.

Thyroid nodules in children are less common than in adults but they are approximately two- to three-fold more likely to be malignant in children. Among thyroid nodular diseases, Plummer's adenoma occurs very rarely in pediatrics, and currently, there is no literature providing evidence of this diagnosis in patients with Prader-Willi syndrome (PWS). We report the case of a 9-year-old Caucasian boy affected by PWS presenting with a rapidly growing palpable mass in the thyroid lodge associated with subclinical hyperthyroidism. Laboratory and other examinations (thyroid ultrasound, fine-needle aspiration of the nodule, and scintigraphy) were strongly suggestive for Plummer's adenoma; therefore, the patient underwent left hemithyroidectomy surgery, and anatomo-pathological examination confirmed the diagnosis. Our case describes the first evidence of an isolated follicular adenoma in children with PWS. Surgery is the only therapeutic option in younger children. Further evidence is needed to assess the possible correlation between these two conditions and the existence of potential risk factors.

Programmed Cell Death Ligand 1 (PD-L1) Immunohistochemical Expression in Advanced Urothelial Bladder Carcinoma: An Updated Review with Clinical and Pathological Implications.

The management of advanced bladder carcinoma involves a multidisciplinary approach, but the prognosis remains poor for many patients. The immune system plays a crucial role in this disease, influencing both tumor development and response to treatment, and exploiting the immune system against the tumor can be a valuable strategy to destroy neoplastic cells. This is the biological principle underlying Bacillus Calmette-Guérin (BCG) use and, more recently, immune checkpoint inhibitors (ICIs), like PD-1 (programmed death-1)/PD-L1 (programmed death-ligand 1) inhibitors. In fact, one of the best studied immune checkpoints is represented by the PD-1/PD-L1 axis, which is a well-known immune escape system adopted by neoplastic bladder cells. PD-L1 expression has been associated with a higher pathologic stage and has shown prognostic value in bladder carcinoma. Interestingly, high-grade bladder cancers tend to express higher levels of PD-1 and PD-L1, suggesting a potential role of such an axis in mediating disease progression. Immunotherapy with PD-1 and PD-L1 inhibitors has therefore emerged as a valuable treatment option and has shown efficacy in advanced bladder cancer patients, with high PD-L1 expression levels associated with better treatment responses. Our review aims to provide a comprehensive overview of the role of PD-L1 in advanced bladder cancer, focusing on its implications for treatment decisions and the prediction of treatment response. Overall, our work aims to contribute to the understanding of PD-L1 as a predictive biomarker and highlight its role in shaping therapeutic approaches for advanced bladder cancer.

The Morphology of Nasal Polyps in Different Age Groups: Histopathological Features.

BACKGROUND: Nasal polyps (NPs) represent the end-stage manifestation of chronic rhinosinusitis (CRS), a relatively common pathological condition encountered in all ages of life. METHODOLOGY: The aim of our study was to evaluate the histological features and inflammatory cellular components of NPs in a retrospective cohort (143 cases) of pediatric, adult and elderly populations in order to discuss the possible morphological age-related differences statistically documented. RESULTS: In the pediatric group, the inflammatory infiltrate presented many eosinophils mixed with lymphocytes, while in the adult population, lymphocytes and plasma cells were mainly evident, frequently with a perivascular distribution or with the formation of subepithelial lymphoid nodules. In the elderly population, inflammation was less evident and was associated with cavernous-like angecthatic structures with thrombotic stratification. Nearly all morphological findings exhibited statistically significant values among differently aged subgroups. CONCLUSIONS: Our results support the presence of histological specificities of NPs at different ages of life, providing new insight into the etiopathogenesis of NPs. The future role of biological therapies, mainly in cases refractory to already available standard medical and surgical treatments, may be analyzed by a prospective study using a larger cohort with a long-term evaluation also in relation to a possible relapse.

Multicancer screening test based on the detection of circulating non haematological proliferating atypical cells.

BACKGROUND: the problem in early diagnosis of sporadic cancer is understanding the individual's risk to develop disease. In response to this need, global scientific research is focusing on developing predictive models based on non-invasive screening tests. A tentative solution to the problem may be a cancer screening blood-based test able to discover those cell requirements triggering subclinical and clinical onset latency, at the stage when the cell disorder, i.e. atypical epithelial hyperplasia, is still in a subclinical stage of proliferative dysregulation. METHODS: a well-established procedure to identify proliferating circulating tumor cells was deployed to measure the cell proliferation of circulating non-haematological cells which may suggest tumor pathology. Moreover, the data collected were processed by a supervised machine learning model to make the prediction. RESULTS: the developed test combining circulating non-haematological cell proliferation data and artificial intelligence shows 98.8% of accuracy, 100% sensitivity, and 95% specificity. CONCLUSION: this proof of concept study demonstrates that integration of innovative non invasive methods and predictive-models can be decisive in assessing the health status of an individual, and achieve cutting-edge results in cancer prevention and management.

Bladder Epicheck Test: A Novel Tool to Support Urothelial Carcinoma Diagnosis in Urine Samples.

Bladder cancer and upper urothelial tract carcinoma are common diseases with a high risk of recurrence, thus necessitating follow-up after initial treatment. The management of non-muscle invasive bladder carcinoma (NMIBC) after transurethral resection involves surveillance, intravesical therapy, and cytology with cystoscopy. Urinary cytology, cystoscopy, and radiological evaluation of the upper urinary tract are recommended during follow-up in the international urological guidelines. Cystoscopy is the standard examination for the first assessment and follow-up of NMIBC, and urine cytology is a widely used urinary test with high sensitivity for high-grade urothelial carcinoma (HGUC) and carcinoma in situ (CIS). In recent years, various urinary assays, including DNA methylation markers, have been used to detect bladder tumors. Among these, the Bladder EpiCheck test is one of the most widely used and is based on analysis of the methylation profile of urothelial cells to detect bladder neoplasms. This review assesses the importance of methylation analysis and the Bladder EpiCheck test as urinary biomarkers for diagnosing urothelial carcinomas in patients in follow-up for NMIBC, helping cytology and cystoscopy in doubtful cases. A combined approach of cytology and methylation analysis is suggested not only to diagnose HGUC, but also to predict clinical and histological recurrences.

Delphi expert consensus for whole slide imaging in thyroid cytopathology.

OBJECTIVE: Despite an increase in thyroid fine needle aspiration (FNA) and advances in whole slide imaging (WSI) adoption, digital pathology is still considered inadequate for primary diagnosis of these cases. Herein, we aim to validate the utility of WSI in thyroid FNAs employing the Delphi method strategy. METHODS: A panel of experts from seven reference cytology centres was recruited. The study consisted of two consecutive rounds: (1) an open-ended, free-response questionnaire generating a list of survey items; and (2) a consensus analysis of 80 selected shared WSIs from 80 cases by six investigators answering six morphological questions utilising a 1 to 5 Likert scale. RESULTS: High consensus was achieved for all parameters, with an overall average score of 4.27. The broad majority of items (84%) were ranked either 4 or 5 by each physician. Two badly scanned cases were responsible for more than half of the low-ranked (≤2) values (57%). Good to excellent (≥3) diagnostic confidence was reached in more than 95.2% of cases. For most cases (78%) WSI assessment was not limited by technical issues linked to the image acquisition process. CONCLUSION: This systematic Delphi study indicates broad consensus among participating physicians on the application of DP to thyroid cytopathology, supporting expert opinion that WSI is reliable and safe for primary diagnostic purposes.

Unusual localization and clinical presentation of primary central nervous system extranodal marginal zone B­cell lymphoma: A case report.

Primary central nervous system (CNS) extranodal marginal zone B-cell lymphoma (MZBL) is a rare low-grade non-Hodgkin lymphoma, characterised predominantly by small B cells, plasma cells, monocytoid cells and scattered large immunoblasts. Primary CNS MZBL is a slow-growing tumour that remains localised and is characterised by an excellent clinical prognosis. The present study describes the case of a 48-year-old HIV-negative female patient with a history of head trauma 1 year prior, who presented with worsening neurological symptoms and a magnetic resonance imaging finding of a ~3-cm extra-axial mass within the left lateral ventricle. From histopathology and immunohistochemistry, the lesion was diagnosed as a CNS MZBL; as no other primary lesions were found, the base of the choroid plexuses of the left lateral ventricle was considered the primary site. To the best of our knowledge, the current case is the first study to report on primary CNS MZBL arising in this anatomical site and paves the way for further studies on the role of chronic inflammation (in the present case resulting from trauma) in the pathogenesis not only of primary CNS MZBL but also of lymphoma in general. Additionally, this report could serve as a starting point for studies analysing the role of meningothelial cells in the pathogenesis of primary CNS MZBL.

Digital Examination of LYmph node CYtopathology Using the Sydney system (DELYCYUS): An international, multi-institutional study.

BACKGROUND: After a series of standardized reporting systems in cytopathology, the Sydney system was recently introduced to address the need for reproducibility and standardization in lymph node cytopathology. Since then, the risk of malignancy for the categories of the Sydney system has been explored by several studies, but no studies have yet examined the interobserver reproducibility of the Sydney system. METHODS: The authors assessed interobserver reproducibility of the Sydney system on 85 lymph node fine-needle aspiration cytology cases reviewed by 15 cytopathologists from 12 institutions in eight different countries, resulting in 1275 diagnoses. In total, 186 slides stained with Diff-Quik, Papanicolaou, and immunocytochemistry were scanned. A subset of the cases included clinical data and results from ultrasound examinations, flow cytometry immunophenotyping, and fluorescence in situ hybridization analysis. The study participants assessed the cases digitally using whole-slide images. RESULTS: Overall, the authors observed an almost perfect agreement of cytopathologists with the ground truth (median weighted Cohen κ = 0.887; interquartile range, κ = 0.210) and moderate overall interobserver concordance (Fleiss κ = 0.476). There was substantial agreement for the inadequate and malignant categories (κ = 0.794 and κ = 0.729, respectively), moderate agreement for the benign category (κ = 0.490), and very slight agreement for the suspicious (κ = 0.104) and atypical (κ = 0.075) categories. CONCLUSIONS: The Sydney system for reporting lymph node cytopathology shows adequate interobserver concordance. Digital microscopy is an adequate means to assess lymph node cytopathology specimens.

Updates from Our Institutional Experience with Thyroid Nodules Diagnosed as Metastases.

BACKGROUND: Thyroid metastases (TMs) are a rare entity, ranging between 0 and 24% in the autopsy series. In the assessment of the best management, the discrimination between a primary and a metastatic thyroid lesion is crucial. In this regard, fine needle aspiration cytology (FNAC) is likely to play a crucial role especially when ancillary techniques (i.e., immunocytochemistry (ICC) and molecular testing) are carried out. METHODS: We searched for all the TMs diagnosed using FNAC and analyzed between 2014 and 2023. The cases were processed with liquid-based (LBC) and ICC and molecular testing performed on LBC-stored material. RESULTS: We reported 2.2% (19 cases) of TMs out of 1022 malignancies. TMs included: 1 larynx carcinoma (LX-Ca), 1 melanoma, 2 breast carcinomas (B-Ca), 3 lung carcinomas (LG-Ca), 4 gastro-intestinal carcinomas (GI-Ca), and 8 clear cell renal carcinomas (CCRC). All patients had a previous cancer history, between 300 and 2 months from the primary cancers. The morphological features were supported by ICC, which were contributive in 100% of cases. All TMs cases were characterized by multiple thyroid nodules except the melanoma case. Four cases underwent total thyroidectomy (1 B, 1 LX, 1 melanoma, and 1 CCRC) whilst 15 TMs were treated with radio-chemotherapy. CONCLUSIONS: FNAC empowered the diagnostic workup of patients with TMs avoiding useless surgery. The low sensitivity of cytology might be reinforced by the application of ancillary techniques. We found a predominant rate of kidney metastatic carcinomas, followed by lung and breast. TMs are frequently multifocal and in a context of a systemic disease so a tailored therapy seems to be the best treatment.

BRAF-AXL-PD-L1 Signaling Axis as a Possible Biological Marker for RAI Treatment in the Thyroid Cancer ATA Intermediate Risk Category.

The use of radioiodine therapy (RIT) is debated in intermediate-risk differentiated thyroid cancer (DTC) patients. The understanding of the molecular mechanisms involved in the pathogenesis of DTC can be useful to refine patient selection for RIT. We analyzed the mutational status of BRAF, RAS, TERT, PIK3 and RET, and the expression of PD-L1 (as a CPS score), the NIS and AXL genes and the tumor-infiltrating lymphocytes (TIL, as the CD4/CD8 ratio), in the tumor tissue in a cohort of forty-six ATA intermediate-risk patients, homogeneously treated with surgery and RIT. We found a significant correlation between BRAF mutations and a less than excellent (LER, according to 2015 ATA classification) response to RIT treatment (p = 0.001), higher expression of the AXL gene (p = 0.007), lower expression of NIS (p = 0.045) and higher expression of PD-L1 (p = 0.004). Moreover, the LER patient group had a significantly higher level of AXL (p = 0.0003), a lower level of NIS (p = 0.0004) and a higher PD-L1 level (p = 0.0001) in comparison to patients having an excellent response to RIT. We also found a significant direct correlation between the AXL level and PD-L1 expression (p < 0.0001) and a significant inverse correlation between AXL and NIS expression and TILs (p = 0.0009 and p = 0.028, respectively). These data suggest that BRAF mutations and AXL expression are involved in LER among DTC patients and in the higher expression of PD-L1 and CD8, becoming new possible biomarkers to personalize RIT in the ATA intermediate-risk group, as well as the use of higher radioiodine activity or other possible therapies.

Autophagic-Related Proteins in Brain Gliomas: Role, Mechanisms, and Targeting Agents.

The present review focuses on the phenomenon of autophagy, a catabolic cellular process, which allows for the recycling of damaged organelles, macromolecules, and misfolded proteins. The different steps able to activate autophagy start with the formation of the autophagosome, mainly controlled by the action of several autophagy-related proteins. It is remarkable that autophagy may exert a double role as a tumour promoter and a tumour suppressor. Herein, we analyse the molecular mechanisms as well as the regulatory pathways of autophagy, mainly addressing their involvement in human astrocytic neoplasms. Moreover, the relationships between autophagy, the tumour immune microenvironment, and glioma stem cells are discussed. Finally, an excursus concerning autophagy-targeting agents is included in the present review in order to obtain additional information for the better treatment and management of therapy-resistant patients.

p53 expression in cytology samples may represent a marker of early-stage cancer.

BACKGROUND: TP53 gene plays a major role in the negative control of cell proliferation and in the regulation of signaling cascades. TP53 mutation may have a relevant role in the malignant transformation of thyroid cells as well as thyroid tumor progression. TP53 mutation has been detected only in few well differentiated thyroid carcinomas and is absent in benign conditions. METHODS: A total of 162 prospective thyroid cytology and corresponding histological samples diagnosed from atypia of indeterminate significance (AUS) to malignant, were studied via immunocytochemistry for p53. Hence, 50 benign lesions (B) were used as negative control. Molecular analysis for p53 only was performed. RESULTS: The cytology resulted in 50 B, 48 AUS, 40 follicular neoplasms (FNs), 23 suspicious for malignancy (SFM), and 1 malignant (M) case. The authors reported 102 negative and 60 positive p53 cases. The 60 positive cases included 27 cases with weak and/or focal cytoplasmic positivity (+1) and 33 with cases moderate (2+) to strong (3+) cytoplasmic and/or nuclear expression. Overall, 71 cases had histology (2 B, 11 AUS, 37 FN, 20 SFM, and 1 M) including 61.7% benign and 38.2% malignant diagnoses. Only 16 of 71 (5 FN, 10 SFM, and 1 M) were p53-positive. Furthermore, 100% AUS and 86.5% FN cases were p53-negative, none of which had malignant histology. All p53-positive cases were associated with a larger nodule size, tall-cell variant subtype, multifocality, extra thyroidal infiltration, and nodal metastases. Noninvasive follicular thyroid neoplasm with papillary like nuclear features were negative for p53. Few discrepancies in p53 intensity were observed on histology; there were no differences with the molecular testing. CONCLUSIONS: p53 might be useful in discriminating thyroid follicular lesions. p53 is likely to be a useful diagnostic marker in recognizing indeterminate lesions that are well-differentiated thyroid cancers.

Cellular and molecular features of COVID-19 associated ARDS: therapeutic relevance.

The severe acute respiratory syndrome-coronavirus-2 (SARS-CoV-2) infection can be asymptomatic or cause a disease (COVID-19) characterized by different levels of severity. The main cause of severe COVID-19 and death is represented by acute (or acute on chronic) respiratory failure and acute respiratory distress syndrome (ARDS), often requiring hospital admission and ventilator support.The molecular pathogenesis of COVID-19-related ARDS (by now termed c-ARDS) is still poorly understood. In this review we will discuss the genetic susceptibility to COVID-19, the pathogenesis and the local and systemic biomarkers correlated with c-ARDS and the therapeutic options that target the cell signalling pathways of c-ARDS.

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

AIMS: Several 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 prognosis and resistance to anticancer therapies, in thyroid cancers the role of PD-L1 remains questionable. Few articles have studied PD-L1 in thyroid fine-needle aspiration cytology (FNAC), demonstrating a possible correlation with papillary thyroid carcinoma. However, its role in oncocytic thyroid lesions remains controversial. We accordingly examine the performance of PD-L1 immunostaining in liquid based cytology (LBC) from oncocytic lesions. METHODS: From January 2019 to March 2021, 114 thyroid lesions diagnosed by FNAC from lesions with a predominant oncocytic component, were enrolled for evaluation by PD-L1 immunostaining on both LBC and corresponding histology samples. RESULTS: The FNAC cohort included 51 benign (B, negative controls), 4 atypia of undetermined significance/follicular lesions of undetermined significance (AUS/FLUS), 57 follicular lesions (follicular neoplasm/suspicious for FN, FN/SFN) and 2 suspicious for malignancy (SFM) cases. Fifty-four cases (11B, 2 AUS/FLUS, 39 FN/SFN and 2 SFM) had histological follow-up including: 1B case resulted as a hyperplastic oxyphilic nodule in Hashimoto thyroiditis (HT), 10B as goitre, 2 AUS/FLUS cases as oncocytic adenomas (OAs); 39 FN/SFN included 27 OAs, 4 FA and 8 oncocytic follicular carcinoma (OFC). The two SFM cases were diagnosed on histopathology as OAs. Increased plasma membrane and cytoplasmic PD-L1 expression were found in 47 cases of the LBC cases (41.2%). Among the histological series, 67.3% of OAs and 75% of OFC had PD-L1 expression, while negative PD-L1 was found in hyperplastic oncocytic cells in HT. A positivity in more than 30% of the neoplastic cells was found in 72.9% of the cases including six OFC. CONCLUSIONS: These data suggest that PD-L1 expression is expressed in oncocytic thyroid lesions. While weak PD-L1 expression failed to discriminate benign from malignant lesions, OFC demonstrated more intense cytoplasmic and membranous expression.

Never stop wondering: When cells become PAP-art on the slides.

The project named Victoria's cells was created to train health care personnel, especially in low-income countries. This innovative approach is designed to associate benign and malignant cellular images and/or patterns with a range of shapes and color shades to evoke animals, common objects, and colorful aquariums. The project makes use of familiar images to capture the viewer's interest as an aid for cytological interpretation. Cervicovaginal cytology is processed with conventional and liquid-based cytology. The images are visually compelling to highlight the importance of studying cells and their diagnostic significance. Infectious diseases as well as malignant cells are thereby easily recognized. The pictures are organized into different sections, including Victoria's zoo, Victoria's fantasy, and malignant mockery. Branching mycelia resemble a starfish; squamous metaplasia recalls a sea turtle's shell. Among others, different patterns of endometrial, endocervical, and squamous cells can resemble fish tanks populated by cells with the shapes of pufferfish, anglerfish, whales, scorpions, and garfish. The sea transitions to the earth, with a sly cat, a little elephant, a dog, and a koala. Other cellular preparations resemble a gymnast, a geisha, and a plunging diver as well as hummingbirds, a heron, a water lily, and a peony. The malignant mockery section is composed of squamous intraepithelial lesion patterns that resemble monsters, eyes, a foul tongue, eagles, and feathers. In conclusion, the recognition of visual images can make the study of cytology simpler and more enjoyable and serve the final objectives of prevention and cure.

Relevance of the College of American Pathologists guideline for validating whole slide imaging for diagnostic purposes to cytopathology.

Whole slide imaging (WSI) allows pathologists to view virtual versions of slides on computer monitors. With increasing adoption of digital pathology, laboratories have begun to validate their WSI systems for diagnostic purposes according to reference guidelines. Among these the College of American Pathologists (CAP) guideline includes three strong recommendations (SRs) and nine good practice statements (GPSs). To date, the application of WSI to cytopathology has been beyond the scope of the CAP guideline due to limited evidence. Herein we systematically reviewed the published literature on WSI validation studies in cytology. A systematic search was carried out in PubMed-MEDLINE and Embase databases up to November 2021 to identify all publications regarding validation of WSI in cytology. Each article was reviewed to determine if SRs and/or GPSs recommended by the CAP guideline were adequately satisfied. Of 3963 retrieved articles, 25 were included. Only 4/25 studies (16%) satisfied all three SRs, with only one publication (1/25, 4%) fulfilling all three SRs and nine GPSs. Lack of a suitable validation dataset was the main missing SR (16/25, 64%) and less than a third of the studies reported intra-observer variability data (7/25, 28%). Whilst the CAP guideline for WSI validation in clinical practice helped the widespread adoption of digital pathology, more evidence is required to routinely employ WSI for diagnostic purposes in cytopathology practice. More dedicated validation studies satisfying all SRs and/or GPSs recommended by the CAP are needed to help expedite the use of WSI for primary diagnosis in cytopathology.

Rare histotypes of epithelial biliary tract tumors: A literature review.

Adenocarcinoma represents the most frequent biliary tract cancer. However, other rare histotypes can be found in the biliary tract, such as cholangiolocellular carcinoma, cholangiocarcinoma with ductal plate malformation pattern, adenosquamous carcinoma, mucinous carcinoma, signet ring cell carcinoma, clear cell carcinoma, mucoepidermoid carcinoma, lymphoepithelioma-like carcinoma, and sarcomatous cholangiocarcinoma. These cancer types account for less than 10 % of all the already rare biliary tract tumors. Yet, they represent a relevant issue in everyday clinical practice, given the lack of therapeutic recommendations and the overall scarcity of data, mainly deriving from isolated small center-specific cohorts of patients.The shifts of such histotypes from the most common ones reflect genetic and molecular differences, determine changes in clinical aggressiveness, and suggest a possible variability in sensitivity to the standard treatments of biliary adenocarcinomas. The consistency and degree of these variables are still to be solidly demonstrated and investigated. Therefore, this paper aims to review the current literature concerning very infrequent and rare epithelial biliary tract cancers, focusing our attention on the clinical, molecular, and immunohistochemical features of these tumors.

DOG1 as an Immunohistochemical Marker of Acinic Cell Carcinoma: A Systematic Review and Meta-Analysis.

DOG1 is a transmembrane protein originally discovered on gastrointestinal stromal tumors and works as a calcium-activated chloride channel protein. There are a limited number of articles on the potential utility of this antibody in the diagnosis of salivary gland tumors in routine practice. In this study, we aimed to investigate the role of DOG1 as an immunohistochemical marker in patients with salivary acinic cell carcinoma (ACC) through meta-analysis. A literature search was performed of the PubMed, Scopus, and Web of Science databases for English-language studies published from January 2010 to September 2021. The literature search revealed 148 articles, of which 20 were included in the study. The overall rate of DOG1 expression in salivary acinic cell carcinoma was 55% (95% CI = 0.43-0.58). Although ACC is a challenging diagnosis, paying careful attention to the cytomorphological features in conjunction with DOG1 immunostaining can help to reach an accurate diagnosis.