A single-dose live-attenuated YF17D-vectored SARS-CoV-2 vaccine candidate.

The expanding pandemic of coronavirus disease 2019 (COVID-19) requires the development of safe, efficacious and fast-acting vaccines. Several vaccine platforms are being leveraged for a rapid emergency response1. Here we describe the development of a candidate vaccine (YF-S0) for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) that uses live-attenuated yellow fever 17D (YF17D) vaccine as a vector to express a noncleavable prefusion form of the SARS-CoV-2 spike antigen. We assess vaccine safety, immunogenicity and efficacy in several animal models. YF-S0 has an excellent safety profile and induces high levels of SARS-CoV-2 neutralizing antibodies in hamsters (Mesocricetus auratus), mice (Mus musculus) and cynomolgus macaques (Macaca fascicularis), and-concomitantly-protective immunity against yellow fever virus. Humoral immunity is complemented by a cellular immune response with favourable T helper 1 polarization, as profiled in mice. In a hamster model2 and in macaques, YF-S0 prevents infection with SARS-CoV-2. Moreover, a single dose conferred protection from lung disease in most of the vaccinated hamsters within as little as 10 days. Taken together, the quality of the immune responses triggered and the rapid kinetics by which protective immunity can be attained after a single dose warrant further development of this potent SARS-CoV-2 vaccine candidate.

Integration of Pathological Criteria and Immunohistochemical Evaluation for Invasive Lobular Carcinoma Diagnosis: Recommendations From the European Lobular Breast Cancer Consortium.

Invasive lobular carcinoma (ILC) is the second most frequent type of breast cancer (BC) and its peculiar morphology is mainly driven by inactivation of CDH1, the gene coding for E-cadherin cell adhesion protein. ILC-specific therapeutic and disease-monitoring approaches are gaining momentum in the clinic, increasing the importance of accurate ILC diagnosis. Several essential and desirable morphologic diagnostic criteria are currently defined by the World Health Organization, the routine use of immunohistochemistry (IHC) for E-cadherin is not recommended. Disagreement in the diagnosis of ILC has been repeatedly reported, but interpathologist agreement increases with the use of E-cadherin IHC. In this study, we aimed to harmonize the pathological diagnosis of ILC by comparing 5 commonly used E-cadherin antibody clones (NCH-38, EP700Y, Clone 36, NCL-L-E-cad [Clone 36B5], and ECH-6). We determined their biochemical specificity for the E-cadherin protein and IHC staining performance according to type and location of mutation on the CDH1 gene. Western blot analysis on mouse cell lines with conditional E-cadherin expression revealed a reduced specificity of EP700Y and NCL-L-E-cad for E-cadherin, with cross-reactivity of Clone 36 to P-cadherin. The use of IHC improved interpathologist agreement for ILC, lobular carcinoma in situ, and atypical lobular hyperplasia. The E-cadherin IHC staining pattern was associated with variant allele frequency and likelihood of nonsense-mediated RNA decay but not with the type or position of CDH1 mutations. Based on these results, we recommend the indication for E-cadherin staining, choice of antibodies, and their interpretation to standardize ILC diagnosis in current pathology practice.

Extensive surgical resections for rare pleural neoplasms: a single-center experience with a yolk sac tumor and synovial sarcoma.

BACKGROUND: Pleural neoplasms are rare and can be subdivided into pleural metastasis and primary pleural neoplasms. Non-mesothelioma primary pleural neoplasms are a diverse group of extremely rare pathologies. CASE PRESENTATION: In this case series, we describe the presentation and management of two rare primary pleural neoplasms. A first case describes a primary pleural yolk sac tumor treated with neoadjuvant chemotherapy, extended pleurectomy decortication, and hyperthermic intrathoracic chemotherapy. In a second case we describe the management of a primary pleural synovial sarcoma by neoadjuvant chemotherapy and extrapleural pneumonectomy. A complete resection was obtained in both cases and the post-operative course was uncomplicated. No signs of tumor recurrence were noted during follow-up in the first patient. In the second patient a local recurrence was diagnosed 6 months after surgery. CONCLUSION: Neo-adjuvant chemotherapy followed by extensive thoracic surgery, including hyperthermic intrathoracic chemotherapy, is a feasible treatment strategy for non-mesothelioma primary pleural neoplasms, but careful follow-up is required.

Association between p16/Ki-67 dual stain cytology results prior to and 6 months after LLETZ treatment for CIN and the follow-up regimen three years after treatment: a retrospective cohort study.

OBJECTIVE: Investigate the association between p16/Ki-67 dual stain cytology test (DST) results, obtained prior to- and 6 months after LLETZ surgery for treatment of CIN, and the follow-up regimen three years after treatment. METHODS: Secondary analysis of a prospective cohort study. Cervical cytology samples were obtained just prior to- and 6 months after LLETZ and underwent conventional liquid-based cytology (LBC) and p16/Ki-67 dual staining, as well as high-risk HPV genotyping. Clinical management after the LLETZ was according to Belgian national guidelines, with clinicians being blinded to DST results at both time points. Case records were reviewed in 01/2023 to document the follow-up regimen on average three years afterwards: women had either been advised to return to routine screening (i.e., three-annual LBC testing according to the Belgian guideline at that time), or were still subject to more frequent posttreatment surveillance (i.e., more frequent visits because of persistent hrHPV infection or absence of cytological regression). RESULTS: The follow-up regimen was recorded in 79/110 women originally recruited (72%). The need for continued intense posttreatment surveillance was associated with hrHPV infection 6 months after treatment (79.3% vs. 18.0%, p < 0.001), a positive DST result at baseline and follow-up (41.4% vs. 84.0%, p < 0.001-55.2% vs. 16.0%, p < 0.001), and persistent cytological anomalies at 6 months (at an ASCUS or worse threshold, 37.9% vs. 16.0%, p = 0.028). In multivariable logistic regression analysis, a positive DST at baseline (aOR 20.1, 95%CI 2.03-199.1) was independently associated with the need for intense post-treatment surveillance multiple years after treatment. CONCLUSION: This exploratory study suggests a possible role of dual-stain cytology in predicting treatment outcome multiple years after LLETZ surgery.

Radiologic and Histologic Correlates of Early Interstitial Lung Changes in Explanted Lungs.

Background Interstitial lung abnormalities (ILAs) reflect imaging features on lung CT scans that are compatible with (early) interstitial lung disease. Despite accumulating evidence regarding the incidence, risk factors, and prognosis of ILAs, the histopathologic correlates of ILAs remain elusive. Purpose To determine the correlation between radiologic and histopathologic findings in CT-defined ILAs in human lung explants. Materials and Methods Explanted lungs or lobes from participants with radiologically documented ILAs were prospectively collected from 2010 to 2021. These specimens were air-inflated, frozen, and scanned with CT and micro-CT (spatial resolution of 0.7 mm and 90 µm, respectively). Subsequently, the lungs were cut and sampled with core biopsies. At least five samples per lung underwent micro-CT and subsequent histopathologic assessment with semiquantitative remodeling scorings. Based on area-specific radiologic scoring, the association between radiologic and histopathologic findings was assessed. Results Eight lung explants from six donors (median age at explantation, 71 years [range, 60-83 years]; four men) were included (unused donor lungs, n = 4; pre-emptive lobectomy for oncologic indications, n = 2). Ex vivo CT demonstrated ground-glass opacification, reticulation, and bronchiectasis. Micro-CT and histopathologic examination demonstrated that lung abnormalities were frequently paraseptal and associated with fibrosis and lymphocytic inflammation. The histopathologic results showed varying degrees of fibrosis in areas that appeared normal on CT scans. Regions of reticulation on CT scans generally had greater fibrosis at histopathologic analysis. Vasculopathy and bronchiectasis were also often present at histopathologic examination of lungs with ILAs. Fully developed fibroblastic foci were rarely observed. Conclusion This study demonstrated direct histologic correlates of CT-defined interstitial lung abnormalities. © RSNA, 2022 Supplemental material is available for this article. See also the editorial by Jeudy in this issue.

A SCID Mouse Model To Evaluate the Efficacy of Antivirals against SARS-CoV-2 Infection.

Ancestral severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) lacks the intrinsic ability to bind to the mouse ACE2 receptor, and therefore establishment of SARS-CoV-2 mouse models has been limited to the use of mouse-adapted viruses or genetically modified mice. Interestingly, some of the variants of concern, such as the Beta B.1.351 variant, show an improved binding to the mouse receptor and hence better replication in different wild-type (WT) mouse species. Here, we describe the establishment of a SARS-CoV-2 Beta B.1.351 variant infection model in male SCID mice as a tool to assess the antiviral efficacy of potential SARS-CoV-2 small-molecule inhibitors. Intranasal infection of male SCID mice with 105 50% tissue culture infective doses (TCID50) of the Beta B.1.351 variant resulted in high viral loads in the lungs and moderate signs of lung pathology on day 3 postinfection. Treatment of infected mice with the antiviral drugs molnupiravir (200 mg/kg, twice a day [BID]) or nirmatrelvir (300 mg/kg, BID) for 3 consecutive days significantly reduced the infectious virus titers in the lungs by 2 and 3.9 log10 TCID50/mg of tissue, respectively, and significantly improved lung pathology. Together, these data demonstrate the validity of this SCID mouse Beta B.1.351 variant infection model as a convenient preclinical model for assessment of potential activity of antivirals against SARS-CoV-2. IMPORTANCE Unlike the ancestral SARS-CoV-2 strain, the Beta (B.1.351) variant of concern has been reported to replicate to some extent in WT mice (C57BL/6 and BALB/c). We demonstrate here that infection of SCID mice with the Beta variant resulted in high viral loads in the lungs on day 3 postinfection. Treatment of infected mice with molnupiravir or nirmatrelvir for 3 consecutive days markedly reduced the infectious virus titers in the lungs and improved lung pathology. The SARS-CoV2 SCID mouse infection model, which is ideally suited for antiviral studies, offers an advantage in comparison to other SARS-CoV2 mouse models, in that there is no need for the use of mouse-adapted virus strains or genetically modified mice. Mouse models also have advantages over hamster models because (i) lower amounts of test drugs are needed, (ii) more animals can be housed in a cage, and (iii) reagents to analyze mouse samples are more readily available than those for hamsters.

Favipiravir at high doses has potent antiviral activity in SARS-CoV-2-infected hamsters, whereas hydroxychloroquine lacks activity.

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) rapidly spread around the globe after its emergence in Wuhan in December 2019. With no specific therapeutic and prophylactic options available, the virus has infected millions of people of which more than half a million succumbed to the viral disease, COVID-19. The urgent need for an effective treatment together with a lack of small animal infection models has led to clinical trials using repurposed drugs without preclinical evidence of their in vivo efficacy. We established an infection model in Syrian hamsters to evaluate the efficacy of small molecules on both infection and transmission. Treatment of SARS-CoV-2-infected hamsters with a low dose of favipiravir or hydroxychloroquine with(out) azithromycin resulted in, respectively, a mild or no reduction in virus levels. However, high doses of favipiravir significantly reduced infectious virus titers in the lungs and markedly improved lung histopathology. Moreover, a high dose of favipiravir decreased virus transmission by direct contact, whereas hydroxychloroquine failed as prophylaxis. Pharmacokinetic modeling of hydroxychloroquine suggested that the total lung exposure to the drug did not cause the failure. Our data on hydroxychloroquine (together with previous reports in macaques and ferrets) thus provide no scientific basis for the use of this drug in COVID-19 patients. In contrast, the results with favipiravir demonstrate that an antiviral drug at nontoxic doses exhibits a marked protective effect against SARS-CoV-2 in a small animal model. Clinical studies are required to assess whether a similar antiviral effect is achievable in humans without toxic effects.

p16/Ki-67 dual stain, PAP cytology and HR-HPV test results prior to and 6 months after a LLETZ procedure: a prospective observational cohort study.

OBJECTIVES: To investigate the effect of a LLETZ procedure on p16/Ki-67 dual stain, PAP cytology and HR-HPV test results on cervical cytology samples obtained prior to and 6 months after the procedure. Secondary aims are to assess dependency between test results at the time of follow-up and explore dual stain positivity rates according to known risk factors for persistence/recurrence of cervical intra-epithelial neoplasia (CIN). STUDY DESIGN: Prospective observational cohort study conducted in the Department of Gynaecology at the University Hospitals of Leuven, Belgium. All patients referred for a LLETZ procedure were invited to participate. A cervical cytology sample was obtained just prior to and 6 months after the procedure. Every sample was used for PAP staining (cytology), p16/Ki-67 dual staining (dual stain test, DST) and HR-HPV genotyping. Test results were compared between both timepoints using the McNemar test. Dependency was assessed cross-sectionally at the time of follow-up using a chi-squared test. RESULTS: From the 110 participants originally included, 83 attended follow-up (75.5%). Mean duration of follow-up was 187.91 days (SD 21.47) and mean age was 41.4 years (SD 11.08). DST positivity rates were 70.9 and 30.1% prior to and 6 months after the procedure (p < 0.001). HR-HPV testing (positive or negative) and abnormal PAP cytology (evaluated at an ASCUS or worse threshold) showed a similar significant reduction in positivity rates (84.5 vs 42.2% and 72.7 vs 28.9%, respectively, p < 0.001). Results of all three assays showed high dependency at the time of follow-up (DST and PAP, PAP and HR-HPV test, DST and HR-HPV test-p values < 0.001). The highest proportion of positive DST results was seen in patients carrying HPV16 (84.6%), followed by any HR-HPV type (60%), those treated for CIN2 + (27.3%) and those with positive margins on the cone specimen (26.7%). CONCLUSION: A LLETZ procedure results in a significant decrease in abnormal DST, PAP cytology and HR-HPV test results in this diverse cohort of patients. The highest proportion of abnormal DST results was seen in patients carrying HR-HPV at the time of follow-up, especially HPV 16.

Expression of phosphorylated ribosomal protein S6 in mesothelioma patients - correlation with clinico-pathological characteristics and outcome: results from the European Thoracic Oncology Platform (ETOP) Mesoscape project.

Pleural mesothelioma (PM) is an aggressive malignancy with poor prognosis. Although histology and pathologic stage are important prognostic factors, better prognostic biomarkers are needed. The ribosomal protein S6 is a downstream target of the phosphatidylinositol 3-kinase (PI3K) pathway involved in protein synthesis and cell proliferation. In previous studies, low phosphorylated S6 (pS6) immunoreactivity was significantly correlated with longer progression-free survival (PFS) and overall survival (OS) in PM patients. We aimed to correlate pS6 expression to clinical data in a large multi-centre PM cohort as part of the European Thoracic Oncology Platform (ETOP) Mesoscape project. Tissue Micro Arrays (TMAs) of PM were constructed and expression of pS6 was evaluated by a semi-quantitatively aggregate H-score. Expression results were correlated to patient characteristics as well as OS/PFS. pS6 IHC results of 364 patients from 9 centres, diagnosed between 1999 and 2017 were available. The primary histology of included tumours was epithelioid (70.3%), followed by biphasic (24.2%) and sarcomatoid (5.5%). TMAs included both treatment-naïve and tumour tissue taken after induction chemotherapy. High pS6 expression (181 patients with H-score>1.41) was significantly associated with less complete resection. In the overall cohort, OS/PFS were not significantly different between pS6-low and pS6-high patients. In a subgroup analysis non-epithelioid (biphasic and sarcomatoid) patients with high pS6 expression showed a significantly shorter OS (p < 0.001, 10.7 versus 16.9 months) and PFS (p < 0.001, 6.2 versus 10.8 months). In subgroup analysis, in non-epithelioid PM patients high pS6 expression was associated with significantly shorter OS and PFS. These exploratory findings suggest a clinically relevant PI3K pathway activation in non-epithelioid PM which might lay the foundation for future targeted treatment strategies.

The Use of Pan-Tropomyosin Receptor Kinase Immunohistochemistry as a Screening Tool for the Detection of Neurotrophic Tropomyosin-Related Kinase Fusions: Real-World Data from a National Multicentric Retrospective Study.

INTRODUCTION: The neurotrophic tropomyosin-related kinase (NTRK) genes encode the tropomyosin receptor kinases (TRKs). Patients with solid tumors harboring an oncogenic NTRK fusion are eligible for treatment with TRK inhibitors. NTRK fusion is often associated with TRK overexpression. Pan-TRK immunohistochemistry (IHC) is used to screen for NTRK fusions, but immunoreactivity patterns are poorly defined. METHODS: Data on pan-TRK immunoreactivity patterns in 2,669 solid tumors (comprising carcinomas, sarcomas, and melanocytic lesions) were retrospectively collected by nine laboratories and comprised tumor type, percentage of pan-TRK-positive tumor cells, staining intensity, cytoplasmic, membrane and/or nuclear staining pattern, and the presence or absence of NTRK fusion. RESULTS: Overall, 2,457 tumors (92%) were pan-TRK negative and 212 neoplasms (8%) were pan-TRK positive. Twenty-two pan-TRK-positive tumors (0.8%) harbored an NTRK fusion, representing 10% of all pan-TRK-positive tumors. Cytoplasmic immunoreactivity was most often observed, followed by membrane immunoreactivity. Nuclear pan-TRK positivity was least frequent, but was most often (33%) associated with NTRK fusion. CONCLUSION: Pan-TRK IHC can be used to screen for NTRK fusions, especially in commonly diagnosed solid tumors with low NTRK fusion prevalence. In case of pan-TRK immunoreactivity, regardless of its intensity and tumor cell percentage, subsequent molecular tests should be performed to formally confirm the presence or absence of NTRK fusions.

Endometriotic lung cyst causing catamenial hemoptysis; a case report and review of literature.

We report a rare case of an endometriotic lung cyst in a 47-year woman with recurrent catamenial hemoptysis. Chest computed tomography (CT) obtained outside the menstruation in October 2019 revealed a cystic lesion (2.5 cm) located in the right inferior lobe near the distal esophagus and the inferior pulmonary vein. Compared to CT abdomen in May 2019, this lesion had increased with a larger volume and a thicker wall. An endometrial lung cyst was suspected as episodes of hemoptysis no longer occurred after initiating hormonal treatment with nomegestrol acetate. Exploratory video-assisted thoracoscopic surgery with wedge resection of the cyst was performed. Histopathologic examination confirmed the diagnosis of an endometriotic cystic lesion. Postoperative course was uneventful with no further symptoms since then.

Molnupiravir Inhibits Replication of the Emerging SARS-CoV-2 Variants of Concern in a Hamster Infection Model.

The emergence of SARS-CoV-2 variants of concern (VoCs) has exacerbated the COVID-19 pandemic. Currently available monoclonal antibodies and vaccines appear to have reduced efficacy against some of these VoCs. Antivirals targeting conserved proteins of SARS-CoV-2 are unlikely to be affected by mutations arising in VoCs and should therefore be effective against emerging variants. We here investigate the efficacy of molnupiravir, currently in phase 2 clinical trials, in hamsters infected with Wuhan strain or B.1.1.7 and B.1.351 variants. Molnupiravir proved to be effective against infections with each of the variants and therefore may have potential combating current and future emerging VoCs.

Hemoptysis after Lung Transplantation Caused by Bronchial Arterial Neovascularization: Angiographic Analysis and Successful Embolization.

This report discusses 3 bilateral lung transplant recipients (2 female, 1 male) who presented with late hemoptysis (10 y, 18 y, and 19 y after transplantation). All patients had a history of pulmonary infections, bronchiectasis, and/or Aspergillus infection. Arteriography, through catherization of the common femoral artery, demonstrated spontaneous bronchial and systemic neovascularization arising from the thyrocervical trunk, internal thoracic artery, intercostal arteries, and dorsal scapular artery. Embolization was performed with microspheres, polyvinyl alcohol microparticles, and/or glue and effectively terminated hemoptysis. One patient died 10 d later as a result of fungal infection, and the 2 others remained in stable condition (18- and 26-mo postembolization follow-up available).

Histopathologic and radiologic assessment of nontransplanted donor lungs.

Donor organ shortage results in significant waiting list mortality. Donor lung assessment is currently based on donors' history, gas exchange, chest X-ray, bronchoscopy findings, and ultimately in situ inspection but remains subjective. We correlated histopathology and radiology in nontransplanted donor lungs with the clinical indications to decline the offered organ. Sixty-two donor lungs, not used for transplantation (2010-2019), were procured, air-inflated, frozen, scanned with computed tomography, systematically sampled, and histologically and radiologically assessed. Thirty-nine (63%) lungs were declined for allograft-related reasons. In 13/39 (33%) lungs, histology could not confirm the reason for decline, in an additional 8/39 (21%) lungs, histologic abnormalities were only considered mild. In 16/39 (41%) lungs, radiology could not confirm the reason for decline. Twenty-three (37%) donor lungs were not transplanted due to extrapulmonary causes, of which three (13%) lungs displayed severe histologic abnormalities (pneumonia, n = 2; emphysema, n = 1), in addition to mild emphysema in 9 (39%) lungs and minor bronchopneumonia in 1 (4%). Radiology revealed ground-glass opacities in 8/23 (35%) and emphysema in 4/23 (17%) lungs. Histopathologic and radiologic assessment of nontransplanted donor lungs revealed substantial discrepancy with the clinical reason for decline. Optimization of donor lung assessment is necessary to improve current organ acceptance rates.

Late-onset "acute fibrinous and organising pneumonia" impairs long-term lung allograft function and survival.

Acute fibrinous and organising pneumonia (AFOP) after lung transplantation is associated with a rapid decline in pulmonary function. However, the relation with chronic lung allograft dysfunction (CLAD) remains unclear. We investigated the association between detection of AFOP in lung allograft biopsies with clinically important endpoints.We reviewed lung allograft biopsies from 468 patients who underwent lung transplantation at the University Hospitals Leuven (2011-2017). AFOP was categorised as early new-onset (≤90 days post-transplant) or late new-onset (>90 days post-transplant); and associated with CLAD-free survival, graft survival, donor-specific antibodies, airway and blood eosinophilia.Early and late AFOP was detected in 24 (5%) and 30 (6%) patients, respectively. CLAD-free survival was significantly lower in patients with late AFOP (median survival 2.42 years; p<0.0001) compared with patients with early or without AFOP and specifically associated with development of restrictive allograft syndrome (OR 28.57, 95% CI 11.34-67.88; p<0.0001). Similarly, graft survival was significantly lower in patients with late AFOP (median survival 4.39 years; p<0.0001) compared with patients with early AFOP or without AFOP. Late AFOP was furthermore associated with detection of circulating donor-specific antibodies (OR 4.75, 95% CI 2.17-10.60; p=0.0004) compared with patients with early or without AFOP, and elevated airway and blood eosinophilia (p=0.043 and p=0.045, respectively) compared with early AFOP patients.Late new-onset AFOP is associated with a worse prognosis and high risk of CLAD development, specifically restrictive allograft syndrome. Our findings indicate that late new-onset AFOP might play a role in the early pathogenesis of restrictive allograft syndrome.

Quantitative analysis of airway obstruction in lymphangioleiomyomatosis.

Lymphangioleiomyomatosis (LAM) is a rare, cystic lung disease with progressive pulmonary function loss caused by progressively proliferating LAM cells. The degree of airway obstruction has not been well investigated within the pathogenesis of LAM.Using a combination of ex vivo computed tomography (CT), microCT and histology, the site and nature of airway obstruction in LAM explant lungs was compared with matched control lungs (n=5 each). The total number of airways per generation, total airway counts, terminal bronchioles number and surface density were compared in LAM versus control.Ex vivo CT analysis demonstrated a reduced number of airways from generation 7 on (p<0.0001) in LAM compared with control, whereas whole-lung microCT analysis confirmed the three- to four-fold reduction in the number of airways. Specimen microCT analysis further demonstrated a four-fold decrease in the number of terminal bronchioles (p=0.0079) and a decreased surface density (p=0.0079). Serial microCT and histology images directly showed the loss of functional airways by collapse of airways on the cysts and filling of the airway by exudate.LAM lungs show a three- to four-fold decrease in the number of (small) airways, caused by cystic destruction which is the likely culprit for the progressive loss of pulmonary function.

Interobserver variation in the assessment of the sarcomatoid and transitional components in biphasic mesotheliomas.

The percentage of sarcomatoid component has an impact on prognosis in patients with biphasic malignant pleural mesothelioma. Recent study showed that the transitional pattern similar to sarcomatoid component of malignant mesothelioma has negative prognostic significance. Practice guidelines recommend quantification of sarcomatoid component despite poor diagnostic reproducibility of biphasic mesothelioma among thoracic pathologists. The aim of this study was to determine the interobserver agreement in the quantification of sarcomatoid component, and in the diagnosis of a transitional component in the biphasic malignant mesothelioma. Thirteen experts in thoracic pathology reviewed the representative H&E and cytokeratin whole-slide images of the 54 biphasic mesotheliomas, without knowledge of BAP1 or p16 deletion status, and completed the survey of 25 questions. The overall interobserver agreement in the assessment of the percentage of the sarcomatoid component in 25% increments was good (wK = 0.62). Excellent agreement was present in 14 of 54 cases (26%), and 3 cases were unanimously scored. Excellent agreement was reached for the cases with 0-24% and > 75% of the sarcomatoid component.The most commonly used criteria for the diagnosis of sarcomatoid component were malignant spindle cells, frank sarcomatoid features and high N/C ratio. The overall interobserver agreement for transitional pattern was fair (wK = 0.40). Unanimous opinion about the absence of transitional pattern was observed in only one case. At least 70% agreement regarding the presence of transitional pattern was observed in 12 cases, with the rest of the cases showing a wide range of disagreement. Morphologic characteristics that favor transitional pattern over non-transitional include sheet-like growth of cohesive, plump, elongated epithelioid cells with well-defined cell borders and a tendency to transition into spindle cells. Our study defined precise morphologic criteria that may be used in the differential diagnosis between transitional pattern and other mesothelioma subtypes including sarcomatoid and epithelioid.

Development and External Validation of a Multiparametric Magnetic Resonance Imaging and International Society of Urological Pathology Based Add-On Prediction Tool to Identify Prostate Cancer Candidates for Pelvic Lymph Node Dissection.

PURPOSE: We sought to expand current prediction tools for lymph node invasion in patients with prostate cancer using current state-of-the-art available tumor information, including multiparametric magnetic resonance imaging based tumor stage and detailed biopsy information. MATERIALS AND METHODS: We selected patients with prostate cancer for study who had available registered information on ISUP (International Society of Urological Pathology) based biopsy grading and multiparametric magnetic resonance imaging, and who had undergone radical prostatectomy with extended pelvic lymph node dissection. We developed a lymph node invasion prediction tool in 420 patients and externally validated it in 187. A concordance index was estimated to quantify the discriminative performance of the model. RESULTS: In the development cohort a median of 21 lymph nodes were removed per patient and 71 patients (16.9%) were diagnosed with lymph node invasion. Statistically significant predictors of lymph node invasion were the initial prostate specific antigen value, multiparametric magnetic resonance imaging based T stage, maximum tumor length in 1 core in mm and ISUP grade group corresponding to the maximum tumor involvement in 1 core. The predictive accuracy of this lymph node invasion prediction tool was 79.7% after fivefold internal cross validation and 72.5% after external validation. CONCLUSIONS: We report a contemporary, externally validated prediction tool for lymph node invasion in patients with prostate cancer. This prediction tool is a response to the paradigm shift from systematic to targeted biopsies by incorporating additional core specific biopsy information instead of the percent of positive cores. This new tool will also overcome stage migration, which is a potential risk when multiparametric magnetic resonance imaging information is used in digital rectal examination based nomograms.

Clinical performance evaluation of the Idylla™ EGFR Mutation Test on formalin-fixed paraffin-embedded tissue of non-small cell lung cancer.

BACKGROUND: Detection of epidermal growth factor receptor (EGFR) mutations in exons 18-21 is recommended in all patients with advanced Non-small-cell lung carcinoma due to the demonstrated efficiency of the standard therapy with tyrosine kinase inhibitors in EGFR-mutated patients. Therefore, choosing a suitable technique to test EGFR mutational status is crucial to warrant a valid result in a short turnaround time using the lowest possible amount of tissue material. The Idylla™ EGFR Mutation Test is a simple, fast and reliable method designed for the detection of EGFR mutations from formalin-fixed paraffin-embedded samples. The aim of this study was the Clinical Performace Evaluation of the Idylla™ EGFR Mutation Test on the Idylla™ System. METHODS: EGFR mutational status was determined on 132 archived formalin-fixed paraffin-embedded tissue sections with Idylla™ technology. Results were compared with the results previously obtained by routine method in the reference lab (Therascreen® EGFR RGQ PCR v2, Qiagen in Molecular Pathology lab, Hospital Universitario Virgen del Rocío de Sevilla). RESULTS: The overall agreement between results obtained with the Idylla™ EGFR Mutation Test and the Comparator test method was 95.38% (with 1-sided 95% lower limit of 91.7%) showing Positive Diagnostic Agreement of 93.22% and Negative Diagnostic Agreement of 97.18%, with a Limit Of Detection ≤5%. CONCLUSIONS: The Idylla™ EGFR Mutation Test passed its clinical validity performance characteristics for accuracy.

A Case of a Heterozygous Inactivating CASR Variant with Adult-Onset Symptomatic Hypercalcemia Requiring Extensive Surgery.

We describe the case of an adult female patient with symptomatic familial hypocalciuric hypercalcemia requiring a step-wise therapeutic approach and the eventual need for a total parathyroidectomy and thyroidectomy to cure symptoms. Genetic analysis demonstrated a heterozygous R227L inactivating CASR gene variant, previously only described in neonatal severe hyperparathyroidism. Post-operative histology showed diffuse hyperplasia of all four parathyroid glands along with the presence of intrathyroidal parathyroid tissue. With regard to clinical management this case suggests that familial hypocalciuric hypercalcemia should be classified as an atypical form of primary hyperparathyroidism rather than a distinct entity.