Anterior insula is more vulnerable than posterior insula to TDP-43 pathology in common dementias and ALS.

Based on the anatomic proximity, connectivity, and functional similarities between the anterior insula and amygdala, we tested the hypothesis that the anterior insula is an important focus in the progression of TDP-43 pathology in LATE-NC. Blinded to clinical and neuropathologic data, phospho-TDP (pTDP) inclusion pathology was assessed in paired anterior and posterior insula samples in 105 autopsied patients with Alzheimer disease, Lewy body disease, LATE-NC and hippocampal sclerosis (HS), amyotrophic lateral sclerosis (ALS), and other conditions. Insular pTDP pathology was present in 34.3% of the study cohort, most commonly as neuronal inclusions and/or short neurites in lamina II, and less commonly as subpial processes resembling those described in the amygdala region. Among positive samples, pTDP pathology was limited to the anterior insula (41.7%), or occurred in both anterior and posterior insula (58.3%); inclusion density was greater in anterior insula across all diseases (p < .001). pTDP pathology occurred in 46.7% of ALS samples, typically without a widespread TDP-43 proteinopathy. In LATE-NC, it was seen in 30.4% of samples (mostly LATE-NC stages 2 and 3), often co-occurring with basal forebrain pathology and comorbid HS, suggesting this is an important step in the evolution of this pathology beyond the medial temporal lobe.

Primary visual cortex pathology in ALS patients with C9ORF72 expansion.

Poly-GA and poly-GP immunofluorescence studies show conspicuous dipeptide repeat pathology in layers IV and II of primary visual cortex in C9ALS patients.

Patterns of amygdala region pathology in LATE-NC: subtypes that differ with regard to TDP-43 histopathology, genetic risk factors, and comorbid pathologies.

Transactive response (TAR) DNA-binding protein 43 kDa (TDP-43) pathology is a hallmark of limbic-predominant age-related TDP-43 encephalopathy (LATE). The amygdala is affected early in the evolution of LATE neuropathologic change (LATE-NC), and heterogeneity of LATE-NC in amygdala has previously been observed. However, much remains to be learned about how LATE-NC originates and progresses in the brain. To address this, we assessed TDP-43 and other pathologies in the amygdala region of 184 autopsied subjects (median age = 85 years), blinded to clinical diagnoses, other neuropathologic diagnoses, and risk genotype information. As previously described, LATE-NC was associated with older age at death, cognitive impairment, and the TMEM106B risk allele. Pathologically, LATE-NC was associated with comorbid hippocampal sclerosis (HS), myelin loss, and vascular disease in white matter (WM). Unbiased hierarchical clustering of TDP-43 inclusion morphologies revealed discernable subtypes of LATE-NC with distinct clinical, genetic, and pathologic associations. The most common patterns were: Pattern 1, with lamina II TDP-43 + processes and preinclusion pathology in cortices of the amygdala region, and frequent LATE-NC Stage 3 with HS; Pattern 2, previously described as type-ß, with neurofibrillary tangle-like TDP-43 neuronal cytoplasmic inclusions (NCIs), high Alzheimer's disease neuropathologic change (ADNC), frequent APOE ε4, and usually LATE-NC Stage 2; Pattern 3, with round NCIs and thick neurites in amygdala, younger age at death, and often comorbid Lewy body disease; and Pattern 4 (the most common pattern), with tortuous TDP-43 processes in subpial and WM regions, low ADNC, rare HS, and lower dementia probability. TDP-43 pathology with features of patterns 1 and 2 were often comorbid in the same brains. Early and mild TDP-43 pathology was often best described to be localized in the "amygdala region" rather than the amygdala proper. There were also important shared attributes across patterns. For example, all four patterns were associated with the TMEM106B risk allele. Each pattern also demonstrated the potential to progress to higher LATE-NC stages with confluent anatomical and pathological patterns, and to contribute to dementia. Although LATE-NC showed distinct patterns of initiation in amygdala region, there was also apparent shared genetic risk and convergent pathways of clinico-pathological evolution.

Single-cell analysis of human glioma and immune cells identifies S100A4 as an immunotherapy target.

A major rate-limiting step in developing more effective immunotherapies for GBM is our inadequate understanding of the cellular complexity and the molecular heterogeneity of immune infiltrates in gliomas. Here, we report an integrated analysis of 201,986 human glioma, immune, and other stromal cells at the single cell level. In doing so, we discover extensive spatial and molecular heterogeneity in immune infiltrates. We identify molecular signatures for nine distinct myeloid cell subtypes, of which five are independent prognostic indicators of glioma patient survival. Furthermore, we identify S100A4 as a regulator of immune suppressive T and myeloid cells in GBM and demonstrate that deleting S100a4 in non-cancer cells is sufficient to reprogram the immune landscape and significantly improve survival. This study provides insights into spatial, molecular, and functional heterogeneity of glioma and glioma-associated immune cells and demonstrates the utility of this dataset for discovering therapeutic targets for this poorly immunogenic cancer.

Fast Progression in Amyotrophic Lateral Sclerosis Is Associated With Greater TDP-43 Burden in Spinal Cord.

Upper and lower motor neuron pathologies are critical to the autopsy diagnosis of amyotrophic lateral sclerosis (ALS). Further investigation is needed to determine how the relative burden of these pathologies affects the disease course. We performed a blinded, retrospective study of 38 ALS patients, examining the association between pathologic measures in motor cortex, hypoglossal nucleus, and lumbar cord with clinical data, including progression rate and disease duration, site of symptom onset, and upper and lower motor neuron signs. The most critical finding in our study was that TAR DNA-binding protein 43 kDa (TDP-43) pathologic burden in lumbar cord and hypoglossal nucleus was significantly associated with a faster progression rate with reduced survival (p < 0.02). There was no correlation between TDP-43 burden and the severity of cell loss, and no significant clinical associations were identified for motor cortex TDP-43 burden or severity of cell loss in motor cortex. C9orf72 expansion was associated with shorter disease duration (p < 0.001) but was not significantly associated with pathologic measures in these regions. The association between lower motor neuron TDP-43 burden and fast progression with reduced survival in ALS provides further support for the study of TDP-43 as a disease biomarker.

Metastatic urothelial carcinoma to the brain, spinal cord and spine: A contemporary multi-institutional clinicopathologic analysis of 24 cases.

Only case reports and small series of metastatic urothelial carcinoma (UCa) to the central nervous system (CNS) or spine have been published. We identified 24 cases at our institutions. The mean patient age was 64 years (range: 41-78 years) with a male predominance. Nineteen (79%) cases involved the brain, 3 (13%) and 2 (8%) cases involved the spinal cord and spine, respectively. Most cases (79%) were a single mass with a mean size of 2.8 cm (range: 0.9-5.5 cm). With the exception of 3 cases demonstrating micropapillary UCa, all metastases showed morphologic features of conventional UCa. Prior to CNS and spinal metastases, there was a history of UCa involving only the bladder in 16 (67%) patients, ureter in 1 (4%) patient, and kidney/renal pelvis in 1 (4%) patient. In 1 additional patient (4%) each, the primary tumor involved both bladder and ureter, bladder and kidney/renal pelvis, and ureter and kidney/renal pelvis, respectively. Three (13%) patients had no known primary site. In two patients, the diagnosis of primary UCa was made concurrently as the CNS metastasis, and ranged up to 30 years in other patients. Follow-up was available in 14 patients with a mean duration of 7 months (range: 0-23 months), and 4 patients died of disease. Both clinicians and pathologists should be aware that concurrent or late CNS or spine metastases may occur and could present as a solitary mass even over a decade after the initial diagnosis.

Evidence-Based Alignment of Pathology Residency With Practice II: Findings and Implications.

This article presents findings from a 4-year series of surveys of new-in-practice pathologists, and a survey of physician employers of new pathologists, assessing how pathology graduate medical education prepares its graduates for practice. Using the methodology described in our previous study, we develop evidence for the importance of residency training for various practice areas, comparing findings over different practice settings, sizes, and lengths of time in practice. The principal findings are (1) while new-in-practice pathologists and their employers report residency generally prepared them well for practice, some areas-billing and coding, laboratory management, molecular pathology, and pathology informatics-consistently were identified as being important in practice but inadequately prepared for in residency; (2) other areas-autopsy pathology, and subspecialized apheresis and blood donor center blood banking services-consistently were identified as relatively unimportant in practice and excessively prepared for in residency; (3) the notion of a single comprehensive model for categorical training in residency is challenged by the disparity between broad general practice in some settings and narrower subspecialty practice in others; and (4) the need for preparation in some areas evolves during practice, raising questions about the appropriate mode and circumstance for training in these areas. The implications of these findings range from rebalancing the emphasis among practice areas in residency, to reconsidering the structure of graduate medical education in pathology to meet present and evolving future practice needs.

Pathology Trainee Redeployment and Education During the COVID-19 Pandemic: An Institutional Experience.

Pathology training programs throughout the United States have endured unprecedented challenges dealing with the ongoing coronavirus disease 2019 pandemic. At Houston Methodist Hospital, the Department of Pathology and Genomic Medicine planned and executed a trainee-oriented, stepwise emergency response. The focus was on optimizing workflows among areas of both clinical and anatomic pathology, maintaining an excellent educational experience, and minimizing trainee exposure to coronavirus disease 2019. During the first phase of the response, trainees were divided into 2 groups: one working on-site and the other working remotely. With the progression of the pandemic, all trainees were called back on-site and further redeployed within our department to meet the significantly increased workload demands of our clinical laboratory services. Adjustments to trainee educational activities included, among others, the organization of a daily coronavirus disease 2019 virtual seminar series. This series served to facilitate communication between faculty, laboratory managers, and trainees. Moreover, it became a forum for trainees to provide updates on individual service workflows and volumes, ongoing projects and research, as well as literature reviews on coronavirus disease 2019-related topics. From our program's experience, redeploying pathology trainees within our department during the coronavirus disease 2019 pandemic resulted in optimization of patient care while ensuring trainee safety, and importantly, helped to maintain continuous high-quality education through active involvement in unique learning opportunities.

Entry of Graduates of US Pathology Residency Programs Into the Workforce: Cohort Data Between 2008 and 2016 Remain Positive and Stable.

The pathologist workforce in the United States is a topic of interest to the health-care community as a whole and to institutions responsible for the training of new pathologists in particular. Although a pathologist shortage has been projected, there has been a pervasive belief by medical students and their advisors that there are "no jobs in pathology." In 2013 and again in 2017, the Program Directors Section of the Association of Pathology Chairs conducted surveys asking pathology residency directors to report the employment status of each of their residents graduating in the previous 5 years. The 2013 Program Directors Section survey indicated that 92% of those graduating in 2010 had obtained employment within 3 years, and 94% of residents graduating in 2008 obtained employment within 5 years. The 2017 survey indicated that 96% of those graduating in 2014 had obtained employment in 3 years, and 97% of residents graduating in 2012 obtained positions within 5 years. These findings are consistent with residents doing 1 or 2 years of fellowship before obtaining employment. Stratification of the data by regions of the country or by the size of the residency programs does not show large differences. The data also indicate a high percentage of employment for graduates of pathology residency programs and a stable job market over the years covered by the surveys.

ATRX protein loss and deregulation of PI3K/AKT pathway is frequent in pilocytic astrocytoma with anaplastic features.

INTRODUCTION: Pilocytic astrocytoma (PA) with anaplastic features (PAAF) is a rare entity associated with decreased survival. It is characterized by hypercellularity, atypia, brisk mitotic activity, variable necrosis, and association with a classic PA component or anaplastic transformation in a recurrent tumor with a previously-documented classic PA. MATERIALS AND METHODS: We present 5 PAAF cases with clinical, radiological, pathological, and molecular correlation. We interrogated ATRX, IDH, TP53, PTEN, EGFR, BRAF, 6q23, p16(Ink4a) by sequencing, FISH, and immunohistochemistry. RESULTS: Four tumors were located in the cerebellum, and 1 was supratentorial. All showed ATRX protein loss by immunohistochemistry, loss of heterozygosity for PTEN, and had no IDH/TP53/BRAF mutations, nor EGFR amplification. Two of 5 tumors showed BRAF duplication by pyrosequencing. All showed loss of PTEN nuclear expression in subsets of tumor cells, which was associated with variable cytoplasmic positivity for pS6. There was a relative correlation between loss of PTEN expression and pS6 cytoplasmic expression. p53 was expressed in ~ 50% of tumor cells in all tumors. P16 was variably lost in all cases. One tumor showed MYB/6q23 deletion. CONCLUSION: We confirm ATRX protein loss suggestive of ATRX alteration as well as dysregulation of the PI3K/AKT pathway and, less often, of the MAPK/ERK pathway in PAAF.
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Teaching Genomic Pathology: Translating Team-Based Learning to a Virtual Environment Using Computer-Based Simulation.

CONTEXT.­: Developing skills related to use of computer-based tools is critical for practicing genomic pathology. However, given the relative novelty of genomics education, residency programs may lack faculty members with adequate expertise and/or time to implement training. A virtual team-based learning (TBL) environment would make genomic pathology education available to more trainees. OBJECTIVE.­: To translate an extensively implemented in-person TBL genomic pathology workshop into a virtual environment and to evaluate both knowledge and skill acquisition. DESIGN.­: Using a novel interactive simulation approach, online modules were developed translating aspects of the TBL experience into the virtual environment with a goal of acquisition of necessary computer-related skills. The modules were evaluated at 10 postgraduate pathology training programs using a pre-post test design with participants deidentified. A postmodule anonymous survey obtained participant feedback on module quality and efficacy. RESULTS.­: There were 147 trainees who received an email request to voluntarily participate in the study. Of these, 43 trainees completed the pretest and 15 (35%) subsequently completed the posttest. Mean overall scores were 45% on the pretest compared with 70% on the posttest ( P < .001; effect size = 1.4). Posttest improvement of results was similar for questions testing acquisition of knowledge versus skills. Regarding the 19 participants who took the survey, 18 (95%) would recommend the modules to others and believed they met the stated objectives. CONCLUSIONS.­: A simulation-based approach allows motivated pathology trainees to acquire computer-related skills for practicing genomic pathology. Future work can explore efficacy in a nonvoluntary setting and adaptation to different specialties, learners, and computer tools.

Trainee Responses to Hurricane Harvey: Correlating Volunteerism With Burnout.

Background: Natural disasters take a heavy toll not only on their victims, but also on physicians who suffer vicarious trauma and burnout. New trainees in Houston, from entering PGY1 residents to entering fellows, underwent even more upheaval and stress during Hurricane Harvey. Many responded to calls for volunteer help. Objective: To investigate the impact of Hurricane Harvey on new trainees at our institution, and correlate volunteerism with measures of burnout and resilience. Methodology: Thirty three new trainees out of 90 (43% of population) from all specialties in our institution voluntarily responded to an online survey on the impact of Hurricane Harvey on their lives, whether or not they volunteered and in what form, and answered questions drawing from the abbreviated Maslach burnout survey and Resiliency Quiz. Statistical analyses were conducted using GraphPad Prism and Excel data analysis. Results: The top areas impacted were emotional health (32%), eating habits (29%), family (25%) and finances (25%). The main voluntary activities were covering for colleagues who could not make it to hospital (50%), donating money and supplies (36%), and cleaning and rebuilding (36%). Volunteering was associated with feelings of appreciation (76%), happiness (62%), thankfulness (57%), purposefulness (43%) and pride (33%). Fewer volunteers scored lowly in personal achievement as compared to non-volunteers (10 vs. 38%, p = 0.05). Significance: Hurricane Harvey affected health, finances and family of new trainees, more than half of whom volunteered to help. Volunteers had a greater sense of personal achievement as compared to non-volunteers. This may be due to having more volunteers among less burnt-out trainees or because volunteering reduced burnout and stress responses/trauma. These results suggest that volunteer opportunities should be made available in programs targeting resident burnout.

Evidence-Based Alignment of Pathology Residency With Practice: Methodology and General Consideration of Results.

Few medical specialties engage in ongoing, organized data collection to assess how graduate medical education in their disciplines align with practice. Pathology educators, the American Board of Pathology, and major pathology organizations undertook an evidence-based, empirical assessment of what all pathologists need to learn in categorical residency. Two challenges were known when we commenced and we encountered 2 others during the project; all were ultimately satisfactorily addressed. Initial challenges were (1) ensuring broad representation of the new-in-practice pathologist experience and (2) adjusting for the effect on this experience of subspecialty fellowship(s) occurring between residency and practice. Additional challenges were (3) needing to assess and quantify degree and extent of subspecialization in different practice settings and (4) measuring changing practice responsibilities with increasing time in practice. We instituted annual surveys of pathologists who are relatively new (<10 years) in practice and a survey of physician employers of new pathologists. The purpose of these surveys was to inform (1) the American Board of Pathology certification process, which needs to assess the most critical knowledge, judgment, and skills required by newly practicing pathologists, and (2) pathology graduate medical education training requirements, which need to be both efficient and effective in graduating competent practitioners. This article presents a survey methodology to evaluate alignment of graduate medical education training with the skills needed for new-in-practice physicians, illustrates an easily interpreted graphical format for assessing survey data, and provides high-level results showing consistency of findings between similar populations of respondents, and between new-in-practice physicians and physician-employers.

Phosphorylated TDP-43 (pTDP-43) aggregates in the axial skeletal muscle of patients with sporadic and familial amyotrophic lateral sclerosis.

Muscle atrophy with weakness is a core feature of amyotrophic lateral sclerosis (ALS) that has long been attributed to motor neuron loss alone. However, several studies in ALS patients, and more so in animal models, have challenged this assumption with the latter providing direct evidence that muscle can play an active role in the disease. Here, we examined the possible role of cell autonomous pathology in 148 skeletal muscle samples from 57 ALS patients, identifying phosphorylated TAR DNA-binding protein (pTDP-43) inclusions in the muscle fibers of 19 patients (33.3%) and 24 tissue samples (16.2% of specimens). A muscle group-specific difference was identified with pTDP-43 pathology being significantly more common in axial (paraspinous, diaphragm) than appendicular muscles (P = 0.0087). This pathology was not significantly associated with pertinent clinical, genetic (c9ALS) or nervous system pathologic data, suggesting it is not limited to any particular subgroup of ALS patients. Among 25 non-ALS muscle samples, pTDP-43 inclusions were seen only in the autophagy-related disorder inclusion body myositis (IBM) (n = 4), where they were more diffuse than in positive ALS samples (P = 0.007). As in IBM samples, pTDP-43 aggregates in ALS were p62/ sequestosome-1-positive, potentially indicating induction of autophagy. Phospho-TDP-43-positive ALS and IBM samples also showed significant up-regulation of TARDBP and SQSTM1 expression. These findings implicate axial skeletal muscle as an additional site of pTDP-43 pathology in some ALS patients, including sporadic and familial cases, which is deserving of further investigation.

Creutzfeldt astrocytes may be seen in IDH-wildtype glioblastoma and retain expression of DNA repair and chromatin binding proteins.

Astrocytes with multiple micronuclei ("Creutzfeldt cells") in a brain biopsy are classically associated with demyelinating disease. However, glioblastoma may also have prominent Creutzfeldt astrocytes, along with granular mitoses. Therefore, Creutzfeldt cells may raise the diagnostic dilemma of high-grade glioma vs tumefactive demyelination. While cases of glioblastoma (GBM) with Creutzfeldt astrocytes have been reported, their clinicopathologic spectrum and genetic features are not understood. Studies have proposed that micronuclei in Creutzfeldt cells are a consequence of DNA damage, or may be susceptible to DNA damage and chromothripsis, but their biology in the context of glioblastoma remains unclear. Based on a challenging index case of GBM with mild hypercellularity, Creutzfeldt astrocytes, and granular mitoses on biopsy, we searched our archives for additional cases with similar histopathologic features. We identified 13 cases, reviewed their clinico-radiologic and pathologic features, and examined them for recurrent genetic alterations via NGS (9 cases) and for evidence of DNA damage by immunohistochemistry for DNA repair and chromatin remodeling proteins. We found that Creutzfeldt cell-rich GBMs were IDH-wildtype with no recurring genetic alterations. To test our hypothesis that micronuclei demonstrate loss of DNA repair or chromatin remodeling proteins, we examined the expression of various proteins (MDM2, p53, MLH1, MSH2, PMS2, MSH6, ATRX, INI1, SATB2, Ki67, pHH3) in Creutzfeldt cell rich-GBM. There was intact expression of DNA repair and chromatin remodeling proteins, with accumulation of p53 and reduced MDM2 expression within micronuclei. In contrast, granular mitoses showed pHH3 expression, confirming these cells are undergoing mitotic division, with no accumulation of p53 and reduced expression of DNA repair proteins. Our results emphasize that Creutzfeldt cells are part of the morphologic spectrum of IDH-wildtype glioblastoma. We did not find a role for DNA damage in the generation of Creutzfeldt cells, as both DNA repair and chromatin remodeling protein expression was retained in these cells.

The Recent Pathology Residency Graduate Job Search Experience: A Synthesis of 5 Years of College of American Pathologists Job Market Surveys.

CONTEXT: - Pathology residents and fellows tailor their training and job search strategies to an actively evolving specialty in the setting of scientific and technical advances and simultaneous changes in health care economics. OBJECTIVE: - To assess the experience and outcome of the job search process of pathologists searching for their first non-fellowship position. DESIGN: - The College of American Pathologists (CAP) Graduate Medical Education Committee has during the past 5 years sent an annual job search survey each June to CAP junior members and fellows in practice 3 years or less who have actively searched for a non-fellowship position. RESULTS: - Job market indicators including job interviews, job offers, positions accepted, and job satisfaction have remained stable during the 5 years of the survey. Most survey respondents who had applied for at least 1 position had accepted a position at the time of the survey, and most applicants who had accepted a position were satisfied or very satisfied. However, most attested that finding a non-fellowship position was difficult. Despite a perceived push toward subspecialization in surgical pathology, the reported number of fellowships completed was stable. Respondent demographics were not associated with job search success with 1 significant exception: international medical school graduate respondents reported greater perceived difficulty in finding a position, and indeed, fewer reported having accepted a position. CONCLUSIONS: - Pathology residents and fellows seeking their first position have faced a relatively stable job market during the last 5 years, with most accepting positions with which they were satisfied.

Recurrent Cerebral Hemorrhage in Normal Pregnancy Secondary to Mycotic Pseudoaneurysms Related to Choriocarcinoma.

BACKGROUND: Choriocarcinoma coexisting with or after normal pregnancy is extremely rare. To our knowledge, our case report is the first time cerebral mycotic pseudoaneurysms from choriocarcinoma have been proven angiographically. CASE DESCRIPTION: A 38-week pregnant 26-year-old woman presented with an acute left frontal hemorrhage. She underwent emergency cesarean section, followed by hematoma evacuation and resection of what grossly appeared to be a medium-sized arteriovenous malformation at the time of surgery. Angiogram before and after resection showed no obvious vascular pathology. One month later, she returned with status epilepticus, and an acute parenchymal hematoma posterior to the surgical resection cavity was identified. Angiography showed a multilobulated pseudoaneurysm along the left middle cerebral artery. This was resected and found on histopathology to have choriocarcinoma within and around the blood vessels. Serum human chorionic gonadotrophin levels increased daily. Pan computed tomography showed a left lung lobular mass. The diagnosis was stage 4 World Health Organization score 9 high-risk metastatic choriocarcinoma requiring radiation followed by multiagent chemotherapy. Two weeks later, she had another seizure. An angiogram showed an unruptured pseudoaneurysm along the right posterior cerebral artery, which was embolized. CONCLUSIONS: Metastatic choriocarcinoma is rarely considered during a viable pregnancy but is almost always fatal if unrecognized. Early recognition enhances the chances of cure with chemotherapy. Arteriovenous malformations are typically considered in young women with intracerebral hemorrhages and have higher risk of rupture in pregnant women, but physicians should also be aware of metastatic choriocarcinoma and the development of mycotic aneurysms in peripartum women with intracerebral hemorrhages.