Cholesterol Clefts Research Articles

MS17.02 Major Pathological Evaluation in Neoadjuvant Immunotherapy

The pathologists play different roles in the care of cancer patients. The main part of this activity is to make the diagnosis of the tumor type, followed by the support to the clinicians in the staging of the patient. In the group of patients that receive Chemotherapy (CT) and / or Radiotherapy (RT) before surgery, the pathologist has to evaluate the results of these treatments by evaluating the tumor bed and the response of the lung. There is a lot of experience in the literature referred to the different types of pathological response to lung cancer treatment after the use of either CT or RT. There are guidelines for the pathologists in order to give an objective evaluation of the treatment results (1). All of them ask the pathologists to evaluate the percentage of viable tumor cells, necrosis and stromal reaction. We can also find different attempts to find molecular markers useful for predicting survival after these traditional treatments (2). In order to have an objective evaluation of the lung cancer patients after CT in 2014 emerged the concept of Major Pathological Response (MPR) as a possible predictor of overall survival (3). This term was applied to describe those patients with a viability of 10% of the tumor cells after neoadjuvant CT. In this report, they propose the MPR as a surrogate endpoint. Since that, the concept of MPR has been used in different reports and assays, becoming a usual parameter for patients with lung resections after receiving chemotherapy. The percentage of viable cells became an important data that has to be evaluated with accuracy in order to avoid subjective results. One of the best ways is to use any of the commercial systems to make measurements on the slides. In our department, we use digital slides to get objective and reproducible data for this type of evaluation. The recent implementation of immunotherapy (IT) for NSCLC that is being applied to an increasing number of patients all over the world makes it necessary to study deeply its morphological effects over de tumor in lung specimens. As most of the patients will never go to the operating room, it becomes important to be aware of the limited knowledge that we have so far. There are some reports comparing the effects of the traditional chemotherapy with immunotherapy. One of these studies shows that the pathologist should look for the same features that are routinely evaluated in the cases after CT (4). The pathologist might evaluate the classic features (viable cells, necrosis and stromal reaction) and other characteristics such as macrophages, cholesterol clefts, lymphoid aggregates, giant cells and neovascularization. In this review, they did not find important differences between the type of morphological changes in both types of treatment, so they propose to use the same parameters in CT and in IT A recent report proposes the concept of Immuno related Pathological Response Criteria (irPRC) (5). They pay attention to the Immune activation with dense lymphoid infiltrate, macrophages and tertiary lymphoid structures as the main characteristics. They also evaluate the massive tumor cell death with destructive features such as cholesterol clefts and those indicative of tissue repair with neovascularization and fibrosis. Last year a review collected different assays done with neoadjuvant IT in patients with resectable lung cancer (6). There is no enough experience in these special groups of patients, as today the IT is given only to advanced lung carcinoma patients. Conclusions: At the present time there are no guidelines for the evaluation of lung tissues after IT. The pathologists have to be aware of the effects of these new biological treatments for lung cancer patients, in order to give as much information as possible in the short number of cases that are seen in the real clinical situation. The previous experience in resected lungs after neoadjuvant therapy is not enough to evaluate the cases after IT. The data obtained from these lung specimens have to give more information in order to improve the knowledge of the effects of these new therapies.

P710S100A4, a key player in plaque stabilization?

Abstract During atherosclerosis, intimal smooth muscle cells (SMCs) acquire a synthetic phenotype. We previously isolated spindle-shaped (S) and rhomboid (R) SMCs from porcine coronary artery. R-SMCs display the features of synthetic/dedifferentiated SMCs. S100A4 was identified as being a marker of R-SMCs in vitro and of intimal SMCs, in pig and man. S-SMCs were treated with multimeric recombinant S100A4, which resulted in partial transition from S- to R-phenotype and NFκB activation. Remarkably, treatment of S-SMCs with multimeric S100A4 and platelet-derived growth factor-BB (PDGF-BB) together induced a complete SMC transition toward a R-phenotype associated with NFκB activation compared with multimeric S100A4 or PDGF-BB alone, likely through toll-like receptor-4 (TLR-4). RNA sequencing showed strong upregulation of pro-inflammatory genes such as granulocyte-macrophage colony stimulating factor (GM-CSF) and matrix-matalloproteinase-3 (MMP-3, Figure A) when cells were treated with multimeric S100A4 and PDGF-BB together compared with multimeric S100A4 or PDGF-BB alone. In vivo, ApoE−/− mice were fed with high-cholesterol diet for 9 weeks. The 3 last weeks they were injected intraperitoneally with neutralizing monoclonal S100A4 antibody (clone 6B12, n=11) or with control IgG1 (n=12). Neutralization of extracellular S100A4 induced: decreased area of atherosclerotic lesions (Figure B), decreased necrotic core and cholesterol cleft, decreased number of CD68 positive cells and increased number of α-smooth muscle actin (Figure C) and smooth muscle myosin heavy chains-positive cells when compared to control groups. S100A4 and SMCs Our results indicate that extracellular S100A4 could be a new target to influence the evolution of atherosclerotic plaque, leading to plaque stabilization. Acknowledgement/Funding Swiss National Science Foundation grant #310030_166357/1

Fibrin-Associated Diffuse Large B-Cell Lymphoma Occurring as a Pararenal Pseudocyst

Abstract A 60-year-old male underwent nephrectomy for a tumor on the posterior aspect of the right kidney. Grossly, a completely encapsulated 8 × 8 × 6.8-cm nodule was found in the perinephric fat adjacent to the renal capsule and indenting the renal surface. The renal parenchyma was microscopically unremarkable. The capsule of the lesion was composed of dense fibrous tissue with chronic inflammation, remote hemorrhage, and prominent calcifications. The nodule/pseudocyst contained predominantly amorphous, eosinophilic material with cholesterol clefts and calcifications. Within the pseudocyst, clusters of large cells were identified. These cells showed abundant amphophilic cytoplasm and large pleomorphic nuclei with dispersed chromatin, prominent nucleoli, and occasional mitotic figures. Immunohistochemical (IHC) staining showed that these cells were positive for CD20, CD79a, IRF4, BCL2 (>90%), C-MYC (70-80%), and EBV-ISH; variably positive for CD30 and PAX5; and negative for CD3, CD10, CD68, CD138, ALK1, and BCL6. MYC FISH break-apart probe demonstrated no rearrangements or copy number changes. Based on the overall features, the diagnosis of fibrin-associated diffuse large B-cell lymphoma (FA-DLBCL) was rendered. This entity has been recently recognized under a larger category of diffuse large B-cell lymphoma associated with chronic inflammation (DLBCL-CI). Unlike DLBCL-CI, which is considered clinically aggressive, FA-DLBCL typically demonstrates a favorable outcome with surgical resection alone. FA-DLBCL is usually incidentally found at unusual sites (cardiac myxomas, prosthetic cardiac valves, thrombi, hematomas, and pseudocysts including intracranial, splenic, retroperitoneal, paratesticular, adrenal, and renal). To our knowledge, this is the first report of a FA-DLBCL arising in a pararenal location. In addition, our case demonstrates unusually high MYC IHC positivity. Although rare, this entity should be kept in mind, especially in an appropriate clinical setting, and should not be misclassified into a more aggressive category, such as “double expressor” DLBCL or DLBCL-CI.

Abstract CT182: Neoadjuvant immuno-radiotherapy (NIRT) in head and neck cancer: Phase I/Ib study of combined PD-1/SBRT prior to surgical resection

Abstract Background: Standard treatment of locally advanced HPV-associated oropharyngeal HNSCC includes definitive chemoRT or surgery followed by risk-adapted adjuvant RT +/- chemo. These approaches provide high rates of long term survival, but are associated with significant subacute as well as long term morbidity. Therefore, increasing efforts have been directed at exploring alternative approaches. Combined SBRT and PD-1 blockade may have particularly favorable properties for anti-tumor immune response in HNSCC (Gough 2009). We present phase I safety & efficacy data from the NIRT trial of neoadjuvant nivolumab/SBRT in oropharyngeal p16+ HNSCC (NCT03247712). Methods: Patients with p16+ oropharyngeal or unknown primary HNSCC, with clinical indications for adjuvant RT, or upfront TORS ineligible due to tumor size, could enroll. Patients received Nivo 240mg IV q2wks x3 prior to surgery, with SBRT to GTV+3mm delivered between Nivo doses 1 & 2, in two dose finding cohorts (n=5 each): 8Gy x5 daily (M-F) and de-escalated 8Gy x3 (M,W,F). Surgery was performed 5 weeks post-SBRT followed by adjuvant Nivo 480mg IV q4wks x3, starting 4 weeks post-op. The primary endpoint was < 33% unplanned surgical delay; the secondary endpoint was pathologic response by irPRC (Cottrell 2018). Results: There were no unplanned surgical delays. All patients had radiologic evidence of decreased tumor size prior to surgery, but none showed a CR by RECIST. Remarkably, the pathologic CR rate was 100% in the 8Gy x 5 cohort (5/5) and 80% In the 8 Gy x 3 cohort (4/5), with the remaining patient achieving MPR (major pathologic response; <10% residual viable tumor). G3 toxicity was observed after surgery in both cohorts but was higher in the 8 Gy x 5 cohort. No G4 or higher toxicity was observed. Interestingly, G2 adrenal insufficiency was observed in 50% (5/10), a higher rate than previously reported with PD-1 blockade for recurrent/metastatic HNSCC. Notably, patients did not experience xerostomia or ageusia rates associated with standard adjuvant radiation in HNSCC. Tissue responses were characterized by robust inflammatory infiltrates into the regression bed and cholesterol clefts, as previously described. Circulating immune cells, baseline tissue, end of RT biopsy and surgical specimen were analyzed using flow cytometry and RNAseq to characterize of immunologic changes over time. There have been no local or distant failures, but median follow up remains < 1 year. Conclusions: Neoadjuvant combined PD-1/SBRT to GTV+3mm dosed at either 8Gy x5 (M-F) or 8Gy x3 (M,W,F) did not delay HNSCC surgery in this Phase I trial (n=10; five per dose). Potent anti-tumor response was observed in all cases (CR=9 + MPR=1). A high response rate and lower toxicity profile favors the 8Gy x3 cohort for development. This study represents a major paradigm shift in the approach to treatment of locally advanced p16+ oropharyngeal cancers. Citation Format: Rom Leidner, R. Bryan Bell, Kristina Young, Brendan Curti, Marcus Couey, Ashish Patel, Amber Watters, Hong Xiao, Carlo Bifulco, Brian Piening, George Morris, Lessli Rushforth, Dawn Brucker, Shorin Nemeth, Michael Gough, Marka Crittenden. Neoadjuvant immuno-radiotherapy (NIRT) in head and neck cancer: Phase I/Ib study of combined PD-1/SBRT prior to surgical resection [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2019; 2019 Mar 29-Apr 3; Atlanta, GA. Philadelphia (PA): AACR; Cancer Res 2019;79(13 Suppl):Abstract nr CT182.

In Vivo Translation of the CIRPI System: Revealing Molecular Pathology of Rabbit Aortic Atherosclerotic Plaques.

Thin-cap fibroatheroma (TCFA) are the unstable lesions in coronary artery disease that are prone to rupture, resulting in substantial morbidity and mortality worldwide. However, their small size and complex morphologic and biologic features make early detection and risk assessment difficult. We tested our newly developed catheter-based Circumferential-Intravascular-Radioluminescence-Photoacoustic-Imaging (CIRPI) system in vivo to enable detection and characterization of vulnerable plaque structure and biology in rabbit abdominal aorta. Methods: The CIRPI system includes a novel optical probe combining circumferential radioluminescence imaging and photoacoustic tomography (PAT). The probe's CaF2:Eu-based scintillating imaging window captures radioluminescence images (360° view) of plaques by detecting β-particles during 18F-FDG decay. A tunable laser-based PAT characterizes tissue constituents of plaque at 7 different wavelengths-540 and 560 nm (calcification), 920 nm (cholesteryl ester), 1040 nm (phospholipids), 1180 nm (elastin/collagen), 1210 nm (cholesterol), and 1235 nm (triglyceride). A single B-scan is concatenated from 330 A-lines captured during a 360° rotation. The abdominal aorta was imaged in vivo in both atherosclerotic rabbits (Watanabe Heritable Hyper Lipidemic [WHHL], 13-mo-old male, n = 5) and controls (New Zealand White, n = 2). Rabbits were fasted for 6 h before 5.55 × 107 Bq (1.5 mCi) of 18F-FDG were injected 1 h before the imaging procedure. Rabbits were anesthetized, and the right or left common carotid artery was surgically exposed. An 8 French catheter sheath was inserted into the common carotid artery, and a 0.035-cm (0.014-in) guidewire was advanced to the iliac artery, guided by x-ray fluoroscopy. A bare metal stent was implanted in the dorsal abdominal aorta as a landmark, followed by the 7 French imaging catheters that were advanced up to the proximal stent edge. Our CIRPI and clinical optical coherence tomography (OCT) were performed using pullback and nonocclusive flushing techniques. After imaging with the CIRPI system, the descending aorta was flushed with contrast agent, and OCT images were obtained with a pullback speed of 20 mm/s, providing images at 100 frames/s. Results were verified with histochemical analysis. Results: Our CIRPI system successfully detected the locations and characterized both stable and vulnerable aortic plaques in vivo among all WHHL rabbits. Calcification was detected from the stable plaque (540 and 560 nm), whereas TCFA exhibited phospholipids/cholesterol (1040 nm, 1210 nm). These findings were further verified with the clinical OCT system showing an area of low attenuation filled with lipids within TCFA. PAT images illustrated broken elastic fiber/collagen that could be verified with the histochemical analysis. All WHHL rabbits exhibited sparse to severe macrophages. Only 4 rabbits showed both moderate-to-severe level of calcifications and cholesterol clefts. However, all rabbits exhibited broken elastic fibers and collagen deposition. Control rabbits showed normal wall thickness with no presence of plaque tissue compositions. These findings were verified with OCT and histochemical analysis. Conclusion: Our novel multimodality hybrid system has been successfully translated to in vivo evaluation of atherosclerotic plaque structure and biology in a preclinical rabbit model. This system proposed a paradigm shift that unites molecular and pathologic imaging technologies. Therefore, the system may enhance the clinical evaluation of TCFA, as well as expand our understanding of coronary artery disease.

Cancer biomarkers in atherosclerotic plaque: Evidenced from structural and proteomic analyses

Atherosclerosis and cancer are the leading causes of mortality around the world that share common pathogenic pathways. The aim of this study is the investigation of the protein profile of atherosclerotic plaque in order to find similar biomarker between cancer and atherosclerosis. The small pieces of human coronary artery containing advanced atherosclerotic plaque is obtained from patients during bypass surgery. Structural characterization of type V plaque, including fibrous connective tissue, necrotic lipid core, cholesterol clefts and calcium deposits are performed using high resolution transmission electron microscopy (HR-TEM). The protein profile of atherosclerosis plaque is also analyzed using 2-dimensional electrophoresis and matrix-assisted laser desorption-ionization time-of-flight (MALDI-TOF). TEM analysis shows that vascular smooth muscle cells (VSMCs) exhibit different and uncommon morphologies in atherosclerotic plaque which is correlated to the proliferative state of the cells. The proteomics analysis reveals proteins related to atherosclerosis formation including Mimecan, Ras Suppressor Protein-1 (RSUP-1) and Cathepsin D which identified as biomarker of cancerous tumors. The expression of Mimecan and RSUP-1 is down-regulated in atherosclerotic plaque while the expression of Cathepsin D is up-regulated. These data support that atherosclerotic plaque presents some degree of tumorgenesis with the significant activity of VSMCs as the key player in atherogenesis.

Cholesteatoma and hydrocephalus associated to a third ventricle meningioma in a cat

ABSTRACT: Meningiomas are neoplasms that commonly involve the central nervous system of cats, while cholesteatomas are nodular granulomatous chronic lesions within the choroid plexus that are rarely reported in cats. This study described a case of cholesteatoma and non-communicating hydrocephalus associated to a third ventricle meningioma in a cat. Clinically, the cat had a 2-year history of behavioral changes, photophobia and motor incoordination. At the necropsy, a tan-brown mass totally occluded the third ventricle, causing a severe dilation of the lateral ventricles (non-communicating hydrocephalus). Microscopically, the mass was composed by a neoplastic proliferation of spindle cells arranged in bundles, containing in the center psammomatous bodies (meningioma), while in the adjacent areas a cholesteatoma was observed, which was characterized by multiple cholesterol cleft formation, hemosiderosis and associated granulomatous inflammation. At immunohistochemistry (IHC), neoplastic cells had a marked immunostaining for vimentin, while were negative for cytokeratin and S100. The diagnosis of transitional meningioma occurring in association to cholesteatoma and non-communicating hydrocephalus in a cat was obtained mainly by the histological and IHC features. These are important methods to distinguish this condition from other neurological disorders in cats.

Inflammasome Activation Aggravates Cutaneous Xanthomatosis and Atherosclerosis in ACAT1 (Acyl-CoA Cholesterol Acyltransferase 1) Deficiency in Bone Marrow

Objective- ACAT1 (Acyl-CoA cholesterol acyltransferase 1) esterifies cellular free cholesterol, thereby converting macrophages to cholesteryl ester-laden foam cells in atherosclerotic lesions and cutaneous xanthoma. Paradoxically, however, loss of ACAT1 in bone marrow causes the aggravation of atherosclerosis and the development of severe cutaneous xanthoma in hyperlipidemic mice. Recently, it has been reported that cholesterol crystals activate NLRP3 (NACHT, LRR [leucine-rich repeats], and PYD [pyrin domain] domain-containing protein 3) inflammasomes, thereby contributing to the development of atherosclerosis. The present study aimed to clarify the role of NLRP3 inflammasomes in the worsening of atherosclerosis and cutaneous xanthoma induced by ACAT1 deficiency. Approach and Results- Ldlr-null mice were transplanted with bone marrow from WT (wild type) mice and mice lacking ACAT1, NLRP3, or both. After the 4 types of mice were fed high-cholesterol diets, we compared their atherosclerosis and skin lesions. The mice transplanted with Acat1-null bone marrow developed severe cutaneous xanthoma, which was filled with numerous macrophages and cholesterol clefts and had markedly increased expression of inflammatory cytokines, and increased atherosclerosis. Loss of NLRP3 completely reversed the cutaneous xanthoma, whereas it improved the atherosclerosis only partially. Acat1-null peritoneal macrophages showed enhanced expression of CHOP (C/EBP [CCAAT/enhancer binding protein] homologous protein) and TNF-α (tumor necrosis factor-α) but no evidence of inflammasome activation, after treatment with acetylated LDL (low-density lipoprotein). Conclusions- Elimination of ACAT1 in bone marrow-derived cells aggravates cutaneous xanthoma and atherosclerosis. The development of cutaneous xanthoma is induced mainly via the NLRP3 inflammasome activation.

1928P - Pathologic assessment following neoadjuvant immunotherapy or chemotherapy demonstrates similar patterns in non-small cell lung cancer (NSCLC)

Background: Neoadjuvant chemotherapy (CT) and immunotherapy (IT) are associated with features of pathologic treatment response (PTR) in NSCLC. Comparison of such features in NSCLC following neoadjuvant CT, IT or upfront surgical resection is lacking. Nivolumab (N) and/or N plus ipilumumab (NI) are being investigated in resectable NSCLC (NCT03158129). We analyzed the histopathologic patterns of CT- and IT-treated NSCLC vs untreated surgically resected tumors. Methods: Histopathologic assessment of untreated, CT- and IT-treated NSCLC was performed (n = 30, 10/group). Hematoxylin and eosin-stained tumor sections were scored for parameters of PTR: percentage of viable tumor, fibrosis, and necrosis; inflammation, tertiary lymphoid structures (TLS), macrophages, lymphovascular invasion (LVI), cholesterol clefts (CC), giant cells (GC) and neovascularization (NV) were reported as a score (0-3). Values for each variable were expressed as a mean (± SD). Statistical comparison between two groups was calculated with unpaired two-sided t-test. Significance was defined as p-value <0.05. Results: CT and IT were associated with significantly less viable tumor cells (p = 0.04 and p = 0.02, respectively), IT with more fibrosis (p = 0.04) and CT with more CC (p = 0.03) than untreated tumors. Trends towards higher amounts of inflammation, macrophages and CC were seen in IT-treated compared to untreated tumors. CT had a trend towards more fibrosis and GC compared with untreated NSCLC (Table).Table: 1928PSummary of PTR parametersUntreatedCT-treatedIT-treatedViable tumor67.7%42.4%*p-value <0.0537.5%*p-value <0.05Fibrosis26.6%46.6%52.3%*p-value <0.05Necrosis5.6%11.0%10.1%Inflammation1.461.541.87TLS0.801.001.00LVI0.230.160.33Macrophages0.120.941.17CC0.130.92*p-value <0.051.04GC0.400.800.70NV000* p-value <0.05 Open table in a new tab Conclusions: Neoadjuvant CT and IT are associated with similar histopathological changes compared to untreated tumors but with lower proportions of viable tumor and higher degrees of fibrosis. Neoadjuvant treatment is also associated with a trend towards higher amounts of inflammation, macrophages, CC and GC. Analysis of a larger cohort, including comparison of N- vs NI-treated tumors (estimated n = 80) is ongoing and will be presented in due course. Clinical trial identification: NCT03158129. Legal entity responsible for the study: University of Texas MD Anderson Cancer Center. Funding: The University of Texas MD Anderson Lung Cancer Moon Shot Program, Bristol-Myers Squibb. Disclosure: B. Glisson: Research funding to institution: Medimmune, Pfizer, ISA Pharmaceuticals, Abbvie. G. Blumenschein: Consulting/advisory role: Bristol-Myers Squibb, Bayer, Clovis, Merck, Celgene, AbbVie, ARIAD; Research funding: Bristol-Myers Squibb, Novartis, Xcovery, AstraZeneca, Adaptimmune, Immatics, Macrogenetics, Bayer, Merck, Celegene, Genentech, GlaxoSmithKline, Kite Pharma; Travel, accomodations, expenses: BMS, AbbVie, Merck. J.V. Heymach: Advisory board: Bristol-Myers Squibb; Research/Grant: Bristol-Myers Squibb. All other authors have declared no conflicts of interest.

Histopathological analysis of the coronary atheroma extracted during coronary artery bypass graft surgery

This study aims to evaluate the histopathological analysis as well as the effect of coronary endarterectomy with severe calcified coronary artery disease. During the year of 2015 to 2017, a total of 135 patients (56 patients of stable angina and 79 patients of unstable angina) underwent atherectomy in adjunct to off-pump coronary artery bypass graft surgery. Histopathological study of atheroma specimen demonstrates the presence of calcification, foam cell, cholesterol clefts, thrombus, smooth muscle cell, and also necrotic tissue using standard hematoxylin and eosin stain techniques. However, smooth muscle cells and foam cell were identified with plaque using the monoclonal antibodies. Thrombus was more common in unstable angina group of patients (64.4%) in comparison to the patients with stable angina (23.2%). An accelerated progression pattern of smooth muscle cell proliferation and calcification were observed which was also common and significantly higher in unstable angina group of patients. The presence of thrombus and accelerated progressive pattern of smooth muscle cell proliferation in unstable angina patients imply the episodic disruption of atheromatous plaque followed by subsequent healing and may play a vital role in the pathophysiology of underlying angina pectoris.

Simple Bone Cyst with Presence of Cholesterol Clefts: Report of a Rare Case in the Mandible

Simple Bone Cyst with Presence of Cholesterol Clefts: Report of a Rare Case in the Mandible

Cholesterol Clefts in Basal Cell Carcinoma: An Under-Recognized Association.

Cholesterol clefts have rarely been described in cutaneous tumors other than lipid-rich tumors. However, they seem to be a relatively common phenomenon in basal cell carcinoma (BCC). This study was undertaken to determine the frequency of cholesterol cleft deposition in BCCs, and to identify associated histopathologic and clinical features. Twenty-eight of 249 BCC cases reviewed showed features of cholesterol cleft. Mean disease duration in those with cholesterol cleft was significantly longer than in those without cholesterol cleft (5.58 vs. 3.29 years, respectively; P = 0.013). Sex and age distributions, and average tumor longest diameter (11.6 vs. 9.41 mm) were no different for those with or without cholesterol clefts. The most common anatomical location was the nose in both those with and without cholesterol clefts. BCCs without cholesterol clefts more frequently involved the periauricular and perioral areas, and areas other than the head and neck, such as the trunk and lower extremities (P = 0.087). Histopathologic features of necrosis (26/28, 92.86%), keratinization (19/28, 67.86%), and pigment deposition (18/28, 64.29%) were found to be associated with cholesterol clefts. Cholesterol clefts were intratumorally located in 27/28 cases (96.43%), and stromally located in 2 cases (7.14%); intravascularly located cholesterol clefts were observed in no case. In conclusion, this study shows that cholesterol clefts are relatively common in BCC, and suggests that cholesterol crystal deposition could be associated with longer disease duration and microtrauma.

Pathologic features of response to neoadjuvant anti-PD-1 in resected non-small-cell lung carcinoma: a proposal for quantitative immune-related pathologic response criteria (irPRC)

BackgroundNeoadjuvant anti-PD-1 may improve outcomes for patients with resectable NSCLC and provides a critical window for examining pathologic features associated with response. Resections showing major pathologic response to neoadjuvant therapy, defined as ≤10% residual viable tumor (RVT), may predict improved long-term patient outcome. However, %RVT calculations were developed in the context of chemotherapy (%cRVT). An immune-related %RVT (%irRVT) has yet to be developed. Patients and methodsThe first trial of neoadjuvant anti-PD-1 (nivolumab, NCT02259621) was just reported. We analyzed hematoxylin and eosin-stained slides from the post-treatment resection specimens of the 20 patients with non-small-cell lung carcinoma who underwent definitive surgery. Pretreatment tumor biopsies and preresection radiographic ‘tumor’ measurements were also assessed. ResultsWe found that the regression bed (the area of immune-mediated tumor clearance) accounts for the previously noted discrepancy between CT imaging and pathologic assessment of residual tumor. The regression bed is characterized by (i) immune activation—dense tumor infiltrating lymphocytes with macrophages and tertiary lymphoid structures; (ii) massive tumor cell death—cholesterol clefts; and (iii) tissue repair—neovascularization and proliferative fibrosis (each feature enriched in major pathologic responders versus nonresponders, P<0.05). This distinct constellation of histologic findings was not identified in any pretreatment specimens. Histopathologic features of the regression bed were used to develop ‘Immune-Related Pathologic Response Criteria’ (irPRC), and these criteria were shown to be reproducible amongst pathologists. Specifically, %irRVT had improved interobserver consistency compared with %cRVT [median per-case %RVT variability 5% (0%–29%) versus 10% (0%–58%), P=0.007] and a twofold decrease in median standard deviation across pathologists within a sample (4.6 versus 2.2, P=0.002). ConclusionsirPRC may be used to standardize pathologic assessment of immunotherapeutic efficacy. Long-term follow-up is needed to determine irPRC reliability as a surrogate for recurrence-free and overall survival.

Abstract LB-154: Pathologic features of response to neoadjuvant anti-PD-1 in resected non-small cell lung carcinoma (NSCLC): A proposal for quantitative immune-related pathologic response criteria (irPRC)

Abstract There is great interest in using PD-(L)1 blockading drugs as neoadjuvant therapy for patients with resectable NSCLC. Early results demonstrated a 45% (9/20) major pathologic response (MPR) rate in patients with Stage I-III NSCLC after receiving nivolumab (NCT02259621). Major pathologic response (MPR) criteria were developed in the context of cytotoxic chemotherapy, defined as ≤10% residual viable tumor cells (RVT). The features of immune-mediated tumor regression following anti-PD-1 have yet to be described. We reviewed H&amp;E-stained slides from resection specimens in 19 patients treated with neoadjuvant nivolumab [n=9 MPR, n=3 partial responders, n=7 non-responders (&amp;gt;70% RVT)] to identify histopathologic features of immune-mediated tumor regression. Specimens were assessed for immune characteristics (tumor infiltrating lymphocyte (TIL) and macrophage density, and presence/absence of, lymphoid aggregates, tertiary lymphoid structures (TLS), dense plasma cell infiltrates, neutrophils, giant cells, etc.) and non-immune features (necrosis, hemosiderin, hyalinized and proliferative fibrosis). We found that immune-mediated tumor regression is characterized by a fibroinflammatory stroma with features of (1) immune activation, including dense TIL and macrophages, TLS, and granulomas; (2) massive [tumor] cell death, including cholesterol clefts and giant cells; and (3) tissue repair, including neovascularization and proliferative fibrosis (each enriched in MPR vs. non-responders, Fisher's exact test p&amp;lt;0.05). An “outside-in” pattern of regression was noted, which has important implications for defining total tumor bed area. As such, we propose “Immune-Related Pathologic Response Criteria” (irPRC), with tumor bed defined by RVT + necrosis + surrounding fibroinflammatory stroma. The areas of each are summed across all slides to calculate %RVT (RVT area/tumor bed area). This differs from chemotherapy MPR criteria, where %RVT is determined for each slide and then averaged, and the distinct fibroinflammatory regression stroma and peripheral regression bed are not acknowledged. The surgical resection specimens were then evaluated by four independent pathologists blinded to response to assess inter-observer variability. Compared to %RVT using chemotherapy criteria, irPRC had improved inter-observer variability [median per-case %RVT variability 5% (0-29%) vs. 10% (0-58%), paired t test p=0.007] and a two-fold decrease in median standard deviation across pathologists within a sample (4.6 vs 2.2, F-test p=0.002). We propose irPRC to standardize pathologic assessment of immune-mediated tumor regression and immunotherapeutic efficacy. Long-term follow up is needed to determine the reliability of irPRC as a surrogate for clinical outcomes such as recurrence-free and overall survival. Citation Format: Tricia R. Cottrell, Julie E. Stein, Jamie E. Chaft, Elizabeth D. Thompson, Natasha Rekhtman, Valsamo Anagnostou, Kellie N. Smith, Amy S. Duffield, Robert A. Anders, James M. Isbell, David R. Jones, Jonathan D. Cuda, Richard Battafarano, Stephen C. Yang, Peter B. Illei, Edward Gabrielson, Frederic Askin, Moises Velez, Matthew D. Hellmann, Jennifer L. Sauter, Ludmila Danilova, Victor E. Velculescu, Jedd D. Wolchok, Suzanne L. Topalian, Julie R. Brahmer, Drew M. Pardoll, Ashley Cimino-Mathews, Patrick M. Forde, Janis M. Taube. Pathologic features of response to neoadjuvant anti-PD-1 in resected non-small cell lung carcinoma (NSCLC): A proposal for quantitative immune-related pathologic response criteria (irPRC) [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr LB-154.

Clinicopathological analysis of 232 radicular cysts of the jawbone in a population of southern Taiwanese patients

This retrospective study aimed to evaluate the clinicopathological features of 232 cases of radicular cyst (January 2001–December 2016) submitted for histopathological examination to Department of Oral Pathology by endodontists in our institution. Demographic data including age, gender, affected site, involved tooth, and histopathological features, were reviewed. The study population comprised 133 females (57.3%) and 99 males (42.7%), with a mean age of 40.5 years and an age range of 13–78 years. Two-hundred and one cysts occurred in the maxilla (86.7%) and 31 in the mandible (13.3%). Most cases involved the anterior teeth of the maxilla (67.2%). The most frequently-involved tooth was the maxillary lateral incisor (50.5%). In most cases (228 cases; 98.3%), the cyst was lined with nonkeratinized stratified squamous epithelium, with two cases containing epithelial lining of the mucoepidermoid epithelium (0.9%) and respiratory epithelium (0.9%), respectively. One case (0.4%) revealed epithelial dysplasia of the epithelial lining. Hyaline body was seen in two cases (0.9%), and Rushton body was noted in seven cases (3.0%). Odontogenic epithelial rest was noted in one case (0.4%). Cholesterol clefts (54 cases; 23.3%), foamy histiocytes (72 cases; 31.0%), hemosiderins (57 cases; 24.6%), dystrophic calcifications (94 cases; 40.5%), foreign bodies (44 cases; 19.0%), and bacterial colonies (22 cases; 9.5%) were also observed. Fifty-three cases (22.8%) showed a mixed acute and chronic inflammatory infiltrate, whereas chronic inflammatory infiltrate only was noted in 179 cases (77.2%). In summary, the current findings provide a valuable source for clinicopathological reference concerning radicular cysts of the jawbone.

Encephalic xanthomas in a large malayan chevrotain ( Tragulus napu )

An adult water chevrotain was euthanized due to severe non-responsive pododermatitis. Incidentally, multiple to coalescing cholesterol granulomas were identified within the right diencephalon, characterized by the presence of foamy macrophages and cholesterol clefts consistent with encephalic xanthomas. No clinical signs or predisposing conditions associated with this finding were identified. This is the first known report of encephalic xanthomas in this species.

Distinguishing a Rare Variant of Lipidized Dermatofibroma from Nonlipidized Dermatofibromas in a Patient with Hypothyroidism and Alopecia Areata

Abstract Introduction. Lipidized dermatofibromas represent rare and often underrecognized variants of dermatofibromas. Histologically, dermatofibromas are composed of fibroblast-like spindle cells, foam cells, giant cells, siderophages, lymphocytes, capillaries, collagen fibers, and hyaline dermal collagen fibers. Lipidized dermatofibromas are characterized by numerous foam cells, Touton giant cells, and hyalinized wiry collagen in the stroma. Case report. We present a case of a 31-year-old woman with a history of hypothyroidism and alopecia areata, presenting with an enlarging 8 mm, firm erythematous nodule on her upper-mid back. Biopsy examination showed a cellular proliferation of spindle cells with peripheral collagen trapping and cholesterol clefts with associated foam cells and sclerosis, staining weakly positive for Factor XIIIa and negative for CD34. The diagnosis of a benign lipidized dermatofibroma was rendered. Conclusion. Lipidized dermatofibromas are rare histologic variants of dermatofibromas, biologically indolent, and should be distinguished from other cutaneous foamy histiocytic lesions, particularly xanthomas, which may alter patient management.

Effects of Karela (Bitter Melon; Momordica charantia) on genes of lipids and carbohydrates metabolism in experimental hypercholesterolemia: biochemical, molecular and histopathological study

BackgroundHypercholesterolemia is a serious diseases associated with type-2 diabetes, atherosclerosis, cardiovascular disorders and liver diseases. Humans seek for safe herbal medication such as karela (Momordica charantia/bitter melon) to treat such disorders to avoid side effect of pharmacotherapies widely used.MethodsForty male Wistar rats were divided into four equal groups; control group with free access to food and water, cholesterol administered group (40 mg/kg BW orally); karela administered group (5 g /kg BW orally) and mixture of cholesterol and karela. The treatments continued for 10 weeks. Karela was given for hypercholesterolemic rats after 6 weeks of cholesterol administration. Serum, liver and epididymal adipose tissues were taken for biochemical, histopathological and genetic assessments.ResultsHypercholesterolemia induced a decrease in serum superoxide dismutase (SOD), catalase, reduced glutathione (GSH) and an increase in malondialdehyde (MDA) levels that were ameliorated by karela administration. Hypercholesterolemia up regulated antioxidants mRNA expression and altered the expression of carbohydrate metabolism genes. In parallel, hypercholesterolemic groups showed significant changes in the expression of PPAR-alpha and gamma, lipolysis, lipogenesis and cholesterol metabolism such as carnitine palmitoyltransferase-1 (CPT-1). Acyl CoA oxidase (ACO), fatty acids synthase (FAS), sterol responsible element binding protein-1c (SREBP1c), 3-hydroxy-3-methylglutaryl coenzyme A reductase (HMG-CoAR) and cholesterol 7α-hydroxylase (CYP7A1) at hepatic and adipose tissue levels. Interestingly, Karela ameliorated all altered genes confirming its hypocholesterolemic effect. Histopathological and immunohistochemical findings revealed that hypercholesterolemia induced hepatic tissue changes compared with control. These changes include cholesterol clefts, necrosis, karyolysis and sever congestion of portal blood vessel. Caspase-3 immunoreactivity showed positive expression in hepatic cells of hypercholesterolemic rats compared to control. All were counteracted and normalized after Karela administration to hypercholesterolemic group.ConclusionCurrent findings confirmed that karela is a potential supplement useful in treatment of hypercholesterolemia and its associated disorders and is good for human health.

Review of xanthomatous lesions of the sella.

Xanthomatous lesions of the sellar region have traditionally been divided into two separate categories, xanthomatous hypophysitis (XH) and xanthogranuloma (XG) of the sellar region. The seminal article on XH, a condition typified by foamy histiocytes and lymphoplasmacytic infiltrates in the pituitary gland/sellar region, but usually little or no hemosiderin pigment, detailed three patients. However, most reports since that time have been single cases, making understanding of the entity difficult. In contrast, the seminal report on XG, characterized by sellar region cholesterol clefts, lymphoplasmacytic infiltrates, marked hemosiderin deposits, fibrosis, multinucleated giant cells around cholesterol clefts, eosinophilic granular necrotic debris, and accumulation of macrophages, included 37 patients, allowing more insights into etiology. Few examples could be linked to adamantinomatous craniopharyngioma, and although ciliated epithelium similar to that of Rathke cleft cyst (RCC) was identified up to 35% of the 37 cases, it could not be proven that XG was related to hemorrhage into RCC. Case reports since that time, however, occasionally linked XG to RCC when an etiology could be identified at all, and a few recognized that a spectrum exists in xanthomatous lesions of the sella. They review literature, adding 23 cases from our own experience, to confirm that overlap occurs between XH and XG, and that the majority-but not all-can be linked to RCC leakage/rupture/hemorrhage. It was suggested that progressive accumulation of hemosiderin pigment in the lesion, possibly caused by the multiple episodes of bleeding, could account for the transition of at least some cases of XH to XG.

Lectin Pathway of Complement Activation Is Associated with Vulnerability of Atherosclerotic Plaques.

Inflammatory mechanisms may be involved in atherosclerotic plaque rupture. By using a novel histology-based method to quantify plaque instability here, we assess whether lectin pathway (LP) of complement activation, a major inflammation arm, could represent an index of plaque instability. Plaques from 42 consecutive patients undergoing carotid endarterectomy were stained with hematoxylin-eosin and the lipid core, cholesterol clefts, hemorrhagic content, thickness of tunica media, and intima, including or not infiltration of cellular debris and cholesterol, were determined. The presence of ficolin-1, -2, and -3 and mannose-binding lectin (MBL), LP initiators, was assessed in the plaques by immunofluorescence and in plasma by ELISA. LP activation was assessed in plasma by functional in vitro assays. Patients presenting low stenosis (≤75%) had higher hemorrhagic content than those with high stenosis (>75%), indicating increased erosion. Increased hemorrhagic content and tunica media thickness, as well as decreased lipid core and infiltrated content were associated with vulnerable plaques and therefore used to establish a plaque vulnerability score that allowed to classify patients according to plaque vulnerability. Ficolins and MBL were found both in plaques’ necrotic core and tunica media. Patients with vulnerable plaques showed decreased plasma levels and intraplaque deposition of ficolin-2. Symptomatic patients experiencing a transient ischemic attack had lower plasma levels of ficolin-1. We show that the LP initiators are present within the plaques and their circulating levels change in atherosclerotic patients. In particular, we show that decreased ficolin-2 levels are associated with rupture-prone vulnerable plaques, indicating its potential use as marker for cardiovascular risk assessment in atherosclerotic patients.