Morphologic changes associated with neoadjuvant-treated pancreatic ductal adenocarcinoma and comparison of two tumor regression grading systems

Pancreatic ductal adenocarcinoma (PDAC) is aggressive, with an overall five-year survival rate of 9%, and few patients are candidates for pancreatectomy at presentation. The role of neoadjuvant therapy (NAT) is evolving, especially for high-risk potentially resectable tumors. Owing to the increasing number of NAT resection specimens, we aim to characterize the histologic changes associated with NAT and to compare two tumor regression grading schemes. One hundred eighteen resections for PDAC were selected from the cases between 2011 and 2018, 59 not treated and 59 treated with NAT. All H&E stained tumor slides were reviewed for histologic changes and graded using the four-tier modified Ryan score (recommended by College of American Pathologists) and the three-tier MD Anderson (MDA) score. The histologic changes evaluated included blue/grey fibrosis, islet cell hyperplasia, dystrophic calcification, amyloid deposition, cholesterol clefts, nerve hypertrophy, elastotic stromal/vascular change, abscess formation, and eosinophilic tumor cell changes. There were statistically significant differences for dystrophic calcification, eosinophilic tumor cell changes, elastotic stromal/vascular change, islet cell hyperplasia, and nerve hypertrophy between the two groups, with these features seen more frequently in NAT cases. Blue/grey stromal fibrosis was present in all cases regardless of NAT, except few complete regression cases and one treated case with intraneural invasion only. Blue/grey fibrosis is a useful histologic visual clue to suggest the possibility of adjacent tumor in the majority of PDAC cases regardless of NAT. By Kaplan-Meier analysis, neither grading scheme correlated with overall survival in our cohort. However, the MDA score was significantly correlated with both time to primary tumor recurrence (p = 0.002) and time to distant recurrence (p = 0.04), whereas the modified Ryan score was not.

Evaluation of A Computer-Aided Detection Software for Prostate Cancer Prediction: Excellent Diagnostic Accuracy Independent of Preanalytical Factors

Prostate cancer (PCa) is the most common noncutaneous cancer in men in the Western world. In addition to accurate diagnosis, Gleason grading and tumor volume estimates are critical for patient management. Computer-aided detection (CADe) software can be used to facilitate the diagnosis and improve the diagnostic accuracy and reporting consistency. However, preanalytical factors such as fixation and staining of prostate biopsy specimens and whole slide images (WSI) on scanners can vary significantly between pathology laboratories and may, therefore, impact the quality of WSI and utility of CADe algorithms. We evaluated the performance of a CADe software in predicting PCa on WSIs of prostate biopsy specimens and focused on whether there were any significant differences in image quality between WSIs obtained on different scanners and specimens from different histopathology laboratories. Thirty prostate biopsy specimens from 2 histopathology laboratories in the United States were included in this study. The hematoxylin and eosin slides of the biopsy specimens were scanned on 3 scanners, generating 90 WSIs. These WSIs were then analyzed using a CADe software (INIFY Prostate, Algorithm), which identified and annotated all areas suspicious for PCa and calculated the tumor volume (percentage area of the biopsy core involved). Study pathologists then reviewed the Algorithm's annotations and tumor volume calculation to confirm the diagnosis and identify benign glands that were misclassified as cancer (false positive) and cancer glands that were misclassified as benign (false negative). The CADe software worked equally well on WSIs from all 3 scanners and from both laboratories, with similar sensitivity and specificity. The overall sensitivity was 99.4%, and specificity was 97%. The percentage of suspicious cancer areas calculated by the Algorithm was similar for all 3 scanners. For WSIs with small foci of cancer (<1 mm), the Algorithm identified all cancer glands (sensitivity, 100%). Preanalytical factors had no significant impact on whole slide imaging and subsequent application of a CADe software. Prediction accuracy could potentially be further improved by processing biopsy specimens in a centralized histology laboratory and training the Algorithm on WSIs from the same laboratory in order to minimize variations in preanalytical factors and optimize the diagnostic performance of the Algorithm.

An unexpected paradox: wall shear stress in the aorta is less in patients with severe atherosclerosis regardless of obesity

BACKGROUND

Obesity is a widespread condition that is more prevalent in Western countries compared to others. Aortic atherosclerosis (AA) is a condition that frequently has been associated with obesity. An obesity paradox, where morbidly obese decedents had either no or minimal AA compared to nonobese decedents, recently has been described by some of us. The explanation for this almost counterintuitive paradox has yet to be determined, but a number of hypotheses were advanced, including hemodynamic factors producing aortic wall shear stress (WSS). The purpose of the present study was to determine if there was a relationship between AA and WSS, as determined by postmortem measurement of aortic wall diameters.

METHODS

Circumferences of the aorta at the levels of the ascending, thoracic and abdominal aorta were measured in 274 consecutive autopsies over 2-year period of time. AA was assessed using a previously described grading scale as either mild or severe. Circumferences were mathematically converted to diameters and WSS was calculated using the Hagen-Poiseuille formula. Two different methods to estimate cardiac output were used, both based on literature methods, one of which was body mass index (BMI) dependent, and the other BMI independent. Univariate and multivariable analyses of the relationship between WSS, age, BMI, gender, race and severity of AA were performed.

RESULTS

Of the 274 decedents, 140 had mild and 134 had moderate to severe AA. BMI <35 was associated with moderate to severe AA. WSS was inversely correlated with AA in all these segments of the aorta in each BMI subgroup with the exception of the ascending aorta for decedents with BMI ≤35 kg/m². Contrary to what we had hypothesized, WSS was not a determinant of the obesity paradox. However, among all the variables analyzed, a history of hypertension, diabetes mellitus and age were significant factors for developing AA (relative risk [RR] 0.35, P = .039; RR 1.51, P = .0006, RR 1.19, P = .0001, respectively).

CONCLUSIONS

Our data demonstrate that WSS was unexpectedly lower in decedents with moderate and severe AA as compared to those with mild AA. This observation, which requires further investigations, was seen in all BMI ranges and was confirmed by 2 methods to calculate WSS.

Comparing Accuracy of Helicobacter pylori Identification Using Traditional Hematoxylin and Eosin-Stained Glass Slides With Digital Whole Slide Imaging

With advancements in the field of digital pathology, there has been a growing need to compare the diagnostic abilities of pathologists using digitized whole slide images against those when using traditional hematoxylin and eosin (H&E)-stained glass slides for primary diagnosis. One of the most common specimens received in pathology practices is an endoscopic gastric biopsy with a request to rule out Helicobacter pylori (H. pylori) infection. The current standard of care is the identification of the organisms on H&E-stained slides. Immunohistochemical or histochemical stains are used selectively. However, due to their small size (2-4 μm in length by 0.5-1 μm in width), visualization of the organisms can present a diagnostic challenge. The goal of the study was to compare the ability of pathologists to identify H. pylori on H&E slides using a digital platform against the gold standard of H&E glass slides using routine light microscopy. Diagnostic accuracy rates using glass slides vs digital slides were 81% vs 72% (P = .0142) based on H&E slides alone. When H. pylori immunohistochemical slides were provided, the diagnostic accuracy was significantly improved to comparable rates (96% glass vs 99% digital, P = 0.2199). Furthermore, differences in practice settings (academic/subspecialized vs community/general) and the duration of sign-out experience did not significantly impact the accuracy of detecting H. pylori on digital slides. We concluded that digital whole slide images, although amenable in different practice settings and teaching environments, does present some shortcomings in accuracy and precision, especially in certain circumstances and thus is not yet fully capable of completely replacing glass slide review for identification of H. pylori. We specifically recommend reviewing glass slides and/or performing ancillary stains, especially when there is a discrepancy between the degree of inflammation and the presence of microorganisms on digital images.

Formalin pre-fixation improves autopsy histology

Microscopic findings in key tissues are often critical to determine the cause of death in medical autopsies. The overall quality of histologic sections depends on numerous pre-analytic factors, among which are tissue section size and thickness. We designed a prospective quality improvement study to determine whether a simple intervention of formalin pre-fixation of myocardium, liver, and kidney tissues could improve the ease of cutting and quality of autopsy histologic sections as assessed by histotechnicians and pathologists. Of 46 autopsies included in the study, 21 were randomly assigned to formalin pre-fixation, and 25 underwent routine sectioning without formalin pre-fixation. A significant improvement in overall quality score by histotechnicians was detected in the sections from pre-fixed autopsy tissues compared to the control group (p=0.0327). There was no significant difference in quality score between the two groups as assessed by pathologists. Our autopsy quality improvement study demonstrates that a simple, low-cost intervention of formalin pre-fixation of fresh autopsy tissues for 90 minutes could significantly improve the overall quality of sections submitted for histologic processing.

Colorectal adenosquamous carcinoma: clinicopathologic analysis of two large cohorts and literature review confirm poor prognosis and reveal prognostic aspects

AIMS

We compiled two cohorts of colorectal adenosquamous carcinoma (ASC) to describe its histologic and molecular aspects using modern parameters to compare them with literature reports using meta-analysis of cohorts and individual case series.

METHODS AND RESULTS

We identified 53 colorectal ASC from 19 North American academic medical centres, in addition to national database reports on 94 Dutch cases. We analysed available clinical, histologic, and immunohistochemical features and patient outcome. ASC comprised 0.02% of colorectal cancers in the Dutch database. The median cohort patient ages at resection were 65 and 69 years (North American and Dutch cohorts, respectively), with a roughly equal male:female ratio. The squamous component represented between 5% and 95% of each tumour, with a median of 50%. Tumour-infiltrating lymphocytes (TILs) were generally low (66%), and tumour budding was often Bd1 (64%). Most cases were pT3 (55%) or pT4 (40%), with nodal metastases in more than half (58%). Twenty-three cases (43%) metastasized distantly, most commonly to the liver. Mismatch repair (MMR) deficiency was identified in 34% of the cases. Follow-up was available for 48 patients; 13 (27%) had recurrent disease and 29 (60%) died. A total of 31 patients progressed, with median time to progression of 18 months. Available data for the Dutch cohort revealed largely similar findings, as did review of cases in the literature.

CONCLUSION

Colorectal ASC usually presents at an advanced stage. Despite high rates of MMR deficiency and low tumour budding, TILs were generally low, and there is a high recurrence rate and poor prognosis.

Recurrent malignant struma ovarii presenting as peritoneal carcinomatosis in the setting of an intact thyroid: A case report and review of the literature

Malignant struma ovarii is an exceedingly rare pathology with a paucity of established criteria regarding management and surveillance with recommendations largely based on case reports and retrospective data. Many authors have supported stratification of malignant struma ovarii into low vs high-risk disease with more conservative management reserved for those deemed low-risk. Here we present a unique case of recurrent metastatic malignant struma ovarii after surveillance was undertaken in the setting of initially low-risk disease.

Pathology and Classification of Peritoneal Surface Malignancies

Peritoneal surface malignancies are rare and represent a diverse group of neoplasms associated with poor prognosis. We review board classification of the primary and secondary peritoneal neoplasms with emphasis on the pathology and recent updates and challenges in the areas of mesothelial neoplasms, peritoneal metastasis, and pseudomyxoma peritonei.

Intraoperative Frozen Section Evaluation of Pancreatic Specimens and Related Liver Lesions

CONTEXT.—

Frozen sections are essential in the surgical management of patients, especially those with pancreatic masses, because frozen sections can provide answers intraoperatively and aid in treatment decisions. Pancreas frozen sections are challenging because of the small tissue size, processing artifacts, neoadjuvant treatment effects, and concurrent pancreatitis-like obstructive changes. The authors present a review of intraoperative evaluation of pancreatic specimens.

OBJECTIVE.—

To provide an approach to the diagnosis of pancreatic adenocarcinoma on frozen sections and to discuss commonly encountered pitfalls. Indications for pancreas frozen sections and specific margin evaluation will be discussed. We will also review frozen section diagnosis of subcapsular liver lesions and tumors other than metastases of pancreatic ductal adenocarcinoma.

DATA SOURCES.—

Data sources included a literature review and the personal experiences of the authors.

CONCLUSIONS.—

The features for diagnosis of pancreatic adenocarcinoma include disordered architecture, glands at abnormal locations, and atypical cytology. It is important to be aware of the pitfalls and clues on frozen section. The evaluation of resection margins can be challenging, and in the setting of the resection of cystic tumors, the key is the diagnosis of high-grade dysplasia or cancer. Finally, it is vital to remember the differential diagnosis for subcapsular liver lesions because not all lesions will be metastases of adenocarcinomas or bile duct adenomas. Frozen sections remain a useful tool for the intraoperative management of patients with pancreatic tumors.

Universal tumor screening for lynch syndrome on colorectal cancer biopsies impacts surgical treatment decisions

Universal tumor screening (UTS) for Lynch syndrome (LS) on colorectal cancer (CRC) can be performed on biopsies or resection specimens. The advantage of biopsies is the chance to provide preoperative genetic counseling/testing (GC/T) so patients diagnosed with LS can make informed decisions regarding resection extent. We evaluated utilization of UTS on biopsies, percentage of patients with deficient mismatch repair (dMMR) who underwent GC/T preoperatively, and whether surgical/treatment decisions were impacted. We performed a retrospective review of medical records to assess CRC cases with dMMR immunohistochemical staining from 1/1/2017 to 2/26/2021. 1144 CRC patients had UTS using MMR immunohistochemistry; 559 biopsies (48.9%) and 585 resections (51.1%). The main reason UTS was not performed on biopsy was it occurred outside our health system. 58 (5%) of CRCs were dMMR and did not have MLH1 promoter hypermethylation (if MLH1 and PMS2 absent). 28/58 (48.3%) of dMMR cases were diagnosed on biopsy. Of those 28, 14 (50%) eventually underwent GC/T, and 7 (25%) had GT results prior to surgery. One of the 7 had incomplete documentation of results affecting their treatment plan. Of the remaining 6 with complete documentation, 5 underwent surgery and one was treated with immunotherapy only. Three patients elected a more extensive surgery. 6/28 (21.4%) dMMR patients identified on biopsy made an informed surgical/treatment decision based on their dMMR status/LS diagnosis. When applied, UTS on biopsy followed by genetic counseling and testing informs surgical decision-making. Process and implementation strategies are in place to overcome challenges to more broadly optimize this approach.

Diagnosis and management of gastric-type endocervical adenocarcinoma: A case report and review of the literature

Gastric-type endocervical adenocarcinoma (GEA), a rare subtype of cervical cancer, has garnered increasing attention recently for its distinctive histopathological features, unique classification, genetic characteristics, and variable clinical outcomes compared to squamous cell and adenocarcinoma subtypes. Historically, GEA has evolved from a poorly understood entity to a distinct subtype of cervical adenocarcinoma, only recently recognized in the 2020 World Health Organization (WHO) classification. Accordingly, characteristic morphological features define GEA, shedding light on the diagnostic challenges and potential misclassification that can occur in clinical practice. Genetic alterations, including KRAS, ARID1A, and PIK3CA mutations, play a pivotal role in the development and progression of GEA. This article reviews a case of GEA and aims to provide a contemporary overview of the genetic mutations and molecular pathways implicated in GEA pathogenesis, highlighting potential therapeutic targets and the prospects of precision medicine in its management. Patients with GEA have variable clinical outcomes, with some exhibiting aggressive behavior while others follow a more indolent course. This review examines the factors contributing to this heterogeneity, including stage at diagnosis, histological grade, and genetic alterations, and their implications for patient prognoses. Treatment strategies for GEA remain a topic of debate and research. Here, we summarize the current therapeutic options, including surgery, radiation therapy, and chemotherapy, while also exploring emerging approaches, such as targeted therapies and immunotherapy. This article provides a comprehensive overview of GEA, synthesizing current knowledge from historical perspectives to contemporary insights, focusing on its classification, genetics, outcomes, and therapeutic strategies.