PTEN Deficiency Induces an Extrahepatic Cholangitis-Cholangiocarcinoma Continuum via Aurora kinase A in Mice.

BACKGROUND & AIMS: The PTEN-AKT pathway is frequently altered in extrahepatic cholangiocarcinoma (eCCA). We aim to evaluate the role of PTEN in the pathogenesis of eCCA and find novel therapies for this disease. METHODS: The Pten gene in the biliary epithelial cells were genetically deleted using the Cre-loxp system. The pathologies were evaluated both macroscopically and histologically. The characteristics were further analyzed by immunohistochemistry (IHC), RT-PCR, cell culture, and RNAseq. Some features were compared to those in human eCCA samples. Further mechanistic studies utilized the conditional knockout of Trp53 and Aurora kinase A (Aurka) genes. Experimental therapy was tested using an Aurka inhibitor. RESULTS: We observed that genetic deletion of the Pten gene in the extrahepatic biliary epithelium and peri-ductal glands initiated sclerosing cholangitis-like lesions in mice, resulting in enlarged and distorted extrahepatic bile ducts in mice as early as one month old. Histologically, these lesions exhibited increased epithelial proliferation, inflammatory cell infiltration, and fibrosis. With aging, the lesions progressed from low-grade dysplasia to invasive carcinoma. Trp53 inactivation further accelerated the disease progression, potentially through downregulating senescence. Further mechanistic studies showed that both human and mouse eCCA showed high expressions of AURKA. Notably, the genetic deletion of Aurka completely eliminated Pten deficiency-induced extrahepatic bile duct lesions. Furthermore, pharmacological inhibition of Aurka alleviated disease progression. CONCLUSIONS: Pten deficiency in extrahepatic cholangiocytes and peribiliary glands led to a cholangitis-to-cholangiocarcinoma continuum through an Aurka-dependent manner. These findings offer new insights into preventive and therapeutic interventions for extrahepatic CCA. IMPACT AND IMPLICATIONS: The aberrant PTEN-PI3K-AKT signaling pathway is commonly observed in human extrahepatic cholangiocarcinoma (eCCA), a disease with a poor prognosis. In our study, we developed a mouse model mimicking cholangitis to eCCA progression by conditionally deleting the Pten gene via Pdx1-Cre in epithelial cells and peribiliary glands of the extrahepatic biliary duct. The conditional Pten deletion in these cells led to cholangitis, which gradually advanced to dysplasia, ultimately resulting in eCCA. The loss of Pten heightened Akt signaling, cell proliferation, inflammation, fibrosis, DNA damage, epigenetic signaling, epithelial-mesenchymal transition (EMT), cell dysplasia, and cellular senescence. Genetic deletion or pharmacological inhibition of Aurka successfully halted the disease progression. This model shall be valuable for testing novel therapies and unraveling the mechanisms of eCCA tumorigenesis.

Non-invasive detection of cardiac allograft rejection among heart transplant recipients using an electrocardiogram based deep learning model.

Aims: Current non-invasive screening methods for cardiac allograft rejection have shown limited discrimination and are yet to be broadly integrated into heart transplant care. Given electrocardiogram (ECG) changes have been reported with severe cardiac allograft rejection, this study aimed to develop a deep-learning model, a form of artificial intelligence, to detect allograft rejection using the 12-lead ECG (AI-ECG). Methods and results: Heart transplant recipients were identified across three Mayo Clinic sites between 1998 and 2021. Twelve-lead digital ECG data and endomyocardial biopsy results were extracted from medical records. Allograft rejection was defined as moderate or severe acute cellular rejection (ACR) based on International Society for Heart and Lung Transplantation guidelines. The extracted data (7590 unique ECG-biopsy pairs, belonging to 1427 patients) was partitioned into training (80%), validation (10%), and test sets (10%) such that each patient was included in only one partition. Model performance metrics were based on the test set (n = 140 patients; 758 ECG-biopsy pairs). The AI-ECG detected ACR with an area under the receiver operating curve (AUC) of 0.84 [95% confidence interval (CI): 0.78-0.90] and 95% (19/20; 95% CI: 75-100%) sensitivity. A prospective proof-of-concept screening study (n = 56; 97 ECG-biopsy pairs) showed the AI-ECG detected ACR with AUC = 0.78 (95% CI: 0.61-0.96) and 100% (2/2; 95% CI: 16-100%) sensitivity. Conclusion: An AI-ECG model is effective for detection of moderate-to-severe ACR in heart transplant recipients. Our findings could improve transplant care by providing a rapid, non-invasive, and potentially remote screening option for cardiac allograft function.

Umbralisib-Induced Immune-Mediated Colitis: A Concerning Adverse Effect of the Novel PI3Kδ/CK1ε Inhibitor.

Novel chemotherapeutic agents are developed to treat recurrent/relapsed lymphoid malignancies. Umbralisib, a novel phosphatidylinositol 3-kinase inhibitor with a selective isoform binding, has shown an improved efficacy and safety profile in clinical trials. Immune-mediated colitis, a frequently observed dose-limiting adverse event of phosphatidylinositol 3-kinase inhibitors, has been mostly observed at supratherapeutic doses in the trials, with grade 1 or 2 diarrhea being the most common adverse event at the therapeutic dose (800 mg PO QD). We present a grade-3 colitis that can be attributed to umbralisib-mediated immune toxicity in a patient with chronic lymphocytic leukemia at the therapeutic dose.

Evaluating the Adoption of Laboratory Practice Guidelines.

CONTEXT.­: To date, the College of American Pathologists (CAP) has developed 17 laboratory practice guidelines (LPGs) including updates. In 2013, the CAP was awarded a 5-year cooperative agreement grant from the United States Centers for Disease Control and Prevention to increase the effectiveness of LPGs. OBJECTIVE.­: To assess the awareness and adoption of 2 CAP LPGs: immunohistochemical (IHC) assay validation and initial workup of acute leukemia. DESIGN.­: Baseline surveys for each LPG were conducted in 2010 and 2015, respectively. To measure the adoption of guideline recommendations and inform future updates, a follow-up study consisting of surveys, telephone interviews, and focus group sessions was conducted in laboratories that indicated they perform IHC testing. A follow-up study for the acute leukemia LPG is planned. RESULTS.­: For the IHC Validation LPG, a total of 1624 survey responses, 40 telephone interviews, and discussions with 5 focus group participants were analyzed. The response rate for the aforementioned 3 modalities was 46%, 13%, and 3%, respectively. All modalities indicated most respondents were aware of the LPG and had adopted most or all of its recommendations. Respondents expressed needs for continued communication, increased specificity, and more prescriptive recommendations when the guideline is updated. CONCLUSIONS.­: While data-driven development of evidence-based LPGs requires significant resources, active data collection to identify gaps and assess adoption contributes to improved laboratory testing practices in support of patient care. The CAP identified sustainable modalities to track metrics and developed multiple tools that should improve guideline development, adoption, and implementation. Of these modalities, written or electronic surveys were the most logistically feasible and had the highest response rate.

Does Donor Allograft Microsteatosis Matter? Comparison of Outcomes in Liver Transplantation With a Propensity-Matched Cohort.

It has been suggested that microsteatosis does not negatively impact graft survival following liver transplantation (LT). The present study represents the largest series on donor livers with significant microsteatosis and investigates the impact of microsteatosis on perioperative factors such as postreperfusion syndrome (PRS), early allograft dysfunction (EAD), and postoperative renal dysfunction. Clinical outcomes of all patients undergoing LT with donor livers with isolated microsteatosis (≥30%; n = 239) between 2000 and 2017 were compared with a propensity score-matched cohort of patients undergoing LT with donor livers with no steatosis (n = 239). Patients in the microsteatosis group had a higher rate of PRS (33.1% versus 24.2%; P = 0.03), EAD (38.2% versus 23.0%; P < 0.001), and continuous renal replacement therapy (CRRT) requirement following LT (10.9% versus 3.6%; P = 0.002) than the no steatosis group. No difference in patient (P = 0.33) or graft survival (P = 0.18) was observed between the 2 groups. On multivariate regression, livers with microsteatosis had an increased risk of graft loss with retransplant recipients (hazard ratio [HR], 1.59; P < 0.001), increasing Model for End-Stage Liver Disease (MELD) score (HR, 1.13; P = 0.01), and organs from donation after circulatory death donors (HR, 1.46; P = 0.003). In conclusion, recipients of donor livers with significant microsteatosis are at an increased risk of PRS, EAD, and postoperative renal dysfunction requiring CRRT. Livers with significant microsteatosis should be avoided in retransplant recipients and in recipients with high biological MELD scores. Once appropriately selected recipients of these livers are able to overcome the initial perioperative implications of using these donor livers, longterm patient and graft survival is similar to recipients receiving grafts with no steatosis.

Analytic Validation of Immunohistochemistry Assays: New Benchmark Data From a Survey of 1085 Laboratories.

CONTEXT: - A cooperative agreement between the College of American Pathologists (CAP) and the United States Centers for Disease Control and Prevention was undertaken to measure laboratories' awareness and implementation of an evidence-based laboratory practice guideline (LPG) on immunohistochemical (IHC) validation practices published in 2014. OBJECTIVE: - To establish new benchmark data on IHC laboratory practices. DESIGN: - A 2015 survey on IHC assay validation practices was sent to laboratories subscribed to specific CAP proficiency testing programs and to additional nonsubscribing laboratories that perform IHC testing. Specific questions were designed to capture laboratory practices not addressed in a 2010 survey. RESULTS: - The analysis was based on responses from 1085 laboratories that perform IHC staining. Ninety-six percent (809 of 844) always documented validation of IHC assays. Sixty percent (648 of 1078) had separate procedures for predictive and nonpredictive markers, 42.7% (220 of 515) had procedures for laboratory-developed tests, 50% (349 of 697) had procedures for testing cytologic specimens, and 46.2% (363 of 785) had procedures for testing decalcified specimens. Minimum case numbers were specified by 85.9% (720 of 838) of laboratories for nonpredictive markers and 76% (584 of 768) for predictive markers. Median concordance requirements were 95% for both types. For initial validation, 75.4% (538 of 714) of laboratories adopted the 20-case minimum for nonpredictive markers and 45.9% (266 of 579) adopted the 40-case minimum for predictive markers as outlined in the 2014 LPG. The most common method for validation was correlation with morphology and expected results. Laboratories also reported which assay changes necessitated revalidation and their minimum case requirements. CONCLUSIONS: - Benchmark data on current IHC validation practices and procedures may help laboratories understand the issues and influence further refinement of LPG recommendations.

Analytic Validation of Immunohistochemical Assays: A Comparison of Laboratory Practices Before and After Introduction of an Evidence-Based Guideline.

CONTEXT: - Laboratories must demonstrate analytic validity before any test can be used clinically, but studies have shown inconsistent practices in immunohistochemical assay validation. OBJECTIVE: - To assess changes in immunohistochemistry analytic validation practices after publication of an evidence-based laboratory practice guideline. DESIGN: - A survey on current immunohistochemistry assay validation practices and on the awareness and adoption of a recently published guideline was sent to subscribers enrolled in one of 3 relevant College of American Pathologists proficiency testing programs and to additional nonsubscribing laboratories that perform immunohistochemical testing. The results were compared with an earlier survey of validation practices. RESULTS: - Analysis was based on responses from 1085 laboratories that perform immunohistochemical staining. Of 1057 responses, 65.4% (691) were aware of the guideline recommendations before this survey was sent and 79.9% (550 of 688) of those have already adopted some or all of the recommendations. Compared with the 2010 survey, a significant number of laboratories now have written validation procedures for both predictive and nonpredictive marker assays and specifications for the minimum numbers of cases needed for validation. There was also significant improvement in compliance with validation requirements, with 99% (100 of 102) having validated their most recently introduced predictive marker assay, compared with 74.9% (326 of 435) in 2010. The difficulty in finding validation cases for rare antigens and resource limitations were cited as the biggest challenges in implementing the guideline. CONCLUSIONS: - Dissemination of the 2014 evidence-based guideline validation practices had a positive impact on laboratory performance; some or all of the recommendations have been adopted by nearly 80% of respondents.

Evaluation of Testing of Acute Leukemia Samples: Survey Result From the College of American Pathologists.

CONTEXT: - The classification and prognosis determination in acute leukemia (AL) are complex and it is unclear what testing is being performed in practice. OBJECTIVE: - To survey physicians describing their current practice of test ordering in the diagnosis of AL. DESIGN: - In anticipation of a guideline by the College of American Pathologists (CAP) and the American Society for Hematology on laboratory testing needed for the initial workup of AL, a baseline survey was designed by an expert panel from CAP. Members of professional societies were asked to describe their current practice of test ordering. RESULTS: - Two hundred ninety-four responses were received with 258 respondents analyzed after the first qualifying survey question regarding initial diagnosis of AL. One hundred seventy-six of 249 respondents (70.7%) were board-certified hematopathologists. Flow cytometry and karyotype analysis were routinely performed for acute myeloid leukemia (AML) (99.1% [232 of 234] and 96.2% [225 of 234], respectively) and acute lymphoblastic leukemia (ALL) (98.3% [229 of 233] and 96.6% [225 of 233], respectively). In addition, fluorescence in situ hybridization studies were routinely performed by 81.2% (190 of 234) of respondents for AML and 85.0% (198 of 233) of respondents for ALL; other molecular studies were performed by 78.2% (183) for AML and 54.9% (128) for ALL; immunohistochemistry by 44.9% (105) for AML and 47.6% (111) for ALL; and cytochemistry by 24.8% (58) for AML and 14.2% (33) for ALL. CONCLUSIONS: - While flow cytometry and karyotyping are routinely reported as being performed for the diagnosis of AL, there is marked variation in the reporting of testing patterns for other genetic studies, immunohistochemistry, and cytochemistry.

Multiple Calcifying Pseudoneoplasms of the Neuraxis.

Calcifying pseudoneoplasms of the neuraxis (CAPNONs) are extremely rare tumors that are frequently misdiagnosed and overlooked by clinicians. To date, only 40 intracranial lesions have been reported, and in all instances, they were found as a solitary calcified mass. To our knowledge, the current case report is the first to illustrate the development of multiple intraaxial CAPNONs and shed more light on the origin of these lesions. We discuss the case of a 67-year-old woman who presented with a six-year history of recurrent seizures. Magnetic resonance imaging revealed two similar heterogeneous intracranial masses in the ventral midbrain and left frontal white matter with indications of more aggressive behavior in the supratentorial tumor. The lesion was resected, and histopathological analysis showed tissue containing nodules of chondromyxoid material with a coarsely fibrillar matrix and focal alveolar pattern. Palisading cells were noted around the edges as well as dystrophic calcifications and osseous metaplasia, consistent with CAPNON. Interestingly, the patient had a previous history of multiple brain abscesses and a mycotic aneurysm. At her four-month follow-up visit, the patient remained seizure-free and there were no indications of residual tumor or recurrence. In contrast to previous reports, intracranial CAPNONs may manifest as multiple lesions and clinicians should include these tumors in the differential diagnosis of intra-axial calcified masses. The previous history of brain abscesses raises the suspicion of an abnormal proliferative process following an insult to the brain tissue as the underlying origin of these lesions.

Professional Practice Evaluation for Pathologists: The Development, Life, and Death of the Evalumetrics Program.

CONTEXT: - In 2008, the Joint Commission (JC) implemented a standard mandating formal monitoring of physician professional performance as part of the process of granting and maintaining practice privileges. OBJECTIVE: - To create a pathology-specific management tool to aid pathologists in constructing a professional practice-monitoring program, thereby meeting the JC mandate. DESIGN: - A total of 105 College of American Pathologists (CAP)-defined metrics were created. Metrics were based on the job descriptions of pathologists' duties in the laboratory, and metric development was aided by experience from the Q-Probes and Q-Tracks programs. The program was offered in a Web-based format, allowing secure data entry, customization of metrics, and central data collection for future benchmarking. RESULTS: - The program was live for 3 years, with 347 pathologists subscribed from 61 practices (median, 4 per institution; range, 1-35). Subscribers used 93 of the CAP-defined metrics and created 109 custom metrics. The median number of CAP-defined metrics used per pathologist was 5 (range, 1-43), and the median custom-defined metrics per pathologist was 2 (range, 1-5). Most frequently, 1 to 3 metrics were monitored (42.7%), with 20% each following 4 to 6 metrics, 5 to 9 metrics, or greater than 10 metrics. Anatomic pathology metrics were used more commonly than clinical pathology metrics. Owing to low registration, the program was discontinued in 2016. CONCLUSIONS: - Through careful vetting of metrics it was possible to develop a pathologist-specific management tool to address the JC mandate. While this initial product failed, valuable metrics were developed and implementation knowledge was gained that may be used to address new regulatory requirements for emerging value-based payment systems.

Genomic profiling of high-grade large-cell neuroendocrine carcinoma of the colon.

High-grade neuroendocrine carcinoma (HGNEC) of the colon is a rare and aggressive cancer that has a poor prognosis. Currently no standard treatment exists, and published case series report an overall survival of approximately one year with treatment. Typically patients receive treatment similar to that recommended for small-cell lung cancer, extrapolating from the similarity in cancer biology. Here we report a case of HGNEC of the colon with genomic profiling that identified a KRAS G12D mutation and a PI3K mutation that has not yet been reported in the literature for this tumor type.

Interpretive Diagnostic Error Reduction in Surgical Pathology and Cytology: Guideline From the College of American Pathologists Pathology and Laboratory Quality Center and the Association of Directors of Anatomic and Surgical Pathology.

CONTEXT: Additional reviews of diagnostic surgical and cytology cases have been shown to detect diagnostic discrepancies. OBJECTIVE: To develop, through a systematic review of the literature, recommendations for the review of pathology cases to detect or prevent interpretive diagnostic errors. DESIGN: The College of American Pathologists Pathology and Laboratory Quality Center in association with the Association of Directors of Anatomic and Surgical Pathology convened an expert panel to develop an evidence-based guideline to help define the role of case reviews in surgical pathology and cytology. A literature search was conducted to gather data on the review of cases in surgical pathology and cytology. RESULTS: The panel drafted 5 recommendations, with strong agreement from open comment period participants ranging from 87% to 93%. The recommendations are: (1) anatomic pathologists should develop procedures for the review of selected pathology cases to detect disagreements and potential interpretive errors; (2) anatomic pathologists should perform case reviews in a timely manner to avoid having a negative impact on patient care; (3) anatomic pathologists should have documented case review procedures that are relevant to their practice setting; (4) anatomic pathologists should continuously monitor and document the results of case reviews; and (5) if pathology case reviews show poor agreement within a defined case type, anatomic pathologists should take steps to improve agreement. CONCLUSIONS: Evidence exists that case reviews detect errors; therefore, the expert panel recommends that anatomic pathologists develop procedures for the review of pathology cases to detect disagreements and potential interpretive errors, in order to improve the quality of patient care.