PPY-cell hyperplasia accompanying NENs: Immunohistochemical and nuclear medicine analysis.

Pancreatic polypeptide cell hyperplasia (PPY-H) is a multiplication of the neuroendocrine cells producing pancreatic polypeptide (PPY). The development and role of PPY-H and its corresponding clinical and imaging findings still need to be fully elucidated. We present 12 cases of PPY-H accompanying pancreatic neuroendocrine neoplasias (NEN). PPY-H was analyzed with the help of immunohistochemistry and confocal microscopy; preoperative clinical data and imaging studies were evaluated retrospectively. We observed PPY-H emerging from pancreatic ducts, and in some cases, we observed simultaneous NKX6.1 positivity in ducts and PPY-H. Additional clinical-pathological correlations suggests that gastrointestinal symptoms (e.g., epigastric pain and cholestasis) could be more related to PPY-H than to NEN hormonal production. In particular cases, SSTR2 expression was strong in PPY-H and correlated with distinguishable accumulation of activity next to NEN on 99 mTc EDDA/Hynic-TOC SPECT/CT. In another case, 18F-FDG-PET/CT showed increased metabolic activity in the area of PPY-H surrounding NEN. Our data suggest that PPY-H originates in the lining of pancreatic ducts. Confirmation of SSTR2 in PPY-H, using immunohistochemistry, suggests the utility of 99 mTc EDDA/Hynic-TOC or 68Ga-DOTA radiotracers in clinical diagnostics; however, studies with larger cohort are needed.

PAR2: The Cornerstone of Pancreatic Diseases.

It has been 30 years since the first member of the protease-activated receptor (PAR) family was discovered. This was followed by the discovery of three other receptors, including PAR2. PAR2 is a G protein-coupled receptor activated by trypsin site-specific proteolysis. The process starts with serine proteases acting between arginine and serine, creating an N-terminus that functions as a tethered ligand that binds, after a conformational change, to the second extracellular loop of the receptor, leading to activation of G-proteins. The physiological and pathological functions of this ubiquitous receptor are still elusive. This review focuses on PAR2 activation and its distribution under physiological and pathological conditions, with a particular focus on the pancreas, a significant producer of trypsin, which is the prototype activator of the receptor. The role in acute or chronic pancreatitis, pancreatic cancer, and diabetes mellitus will be highlighted.

Predictive testing in non-small cell lung carcinoma.

BACKGROUND: Predictive testing is a crucial part of the complete diagnostic process of non-small cell lung cancer (NSCLC) and a necessary requirement in order to determine proper course of treatment. However, the possibilities of testing and the spectrum of examined markers are quickly evolving as a result of the progress in diagnostic and therapeutic possibilities, and as such it is necessary to regularly update the current guidelines to achieve proper standards of care in routine practice. PURPOSE: To provide a complex overview of the current problematics of predictive testing in NSCLC at a molecular level, considering also the evaluation of PD-L1 expression based on the international and national guidelines. To summarize the current state of predictive testing employed in NSCLC in the Czech Republic. CONCLUSION: Predictive testing in NSCLC is a part of routine diagnostic practice; however, as a result of the expanding spectrum of diagnostic and therapeutic possibilities, it is undergoing significant development. The existing method of the sequential testing of individual markers is becoming unsuitable; given the increasing number of potential predictors and complex molecular testing, the use of new generation sequencing appears to represent a more suitable solution. The immunohistochemical evaluation of PD-L1 expression is also a necessary part of predictive testing in NSCLC.

Clinical and molecular practice of European thoracic pathology laboratories during the COVID-19 pandemic. The past and the near future.

BACKGROUND: This study evaluated the consequences in Europe of the COVID-19 outbreak on pathology laboratories orientated toward the diagnosis of thoracic diseases. MATERIALS AND METHODS: A survey was sent to 71 pathology laboratories from 21 European countries. The questionnaire requested information concerning the organization of biosafety, the clinical and molecular pathology, the biobanking, the workload, the associated research into COVID-19, and the organization of education and training during the COVID-19 crisis, from 15 March to 31 May 2020, compared with the same period in 2019. RESULTS: Questionnaires were returned from 53/71 (75%) laboratories from 18 European countries. The biosafety procedures were heterogeneous. The workload in clinical and molecular pathology decreased dramatically by 31% (range, 3%-55%) and 26% (range, 7%-62%), respectively. According to the professional category, between 28% and 41% of the staff members were not present in the laboratories but did teleworking. A total of 70% of the laboratories developed virtual meetings for the training of residents and junior pathologists. During the period of study, none of the staff members with confirmed COVID-19 became infected as a result of handling samples. CONCLUSIONS: The COVID-19 pandemic has had a strong impact on most of the European pathology laboratories included in this study. Urgent implementation of several changes to the organization of most of these laboratories, notably to better harmonize biosafety procedures, was noted at the onset of the pandemic and maintained in the event of a new wave of infection occurring in Europe.

[Evaluation of Inflammatory Cells (Tumor Infiltrating Lymphocytes) in Solid Tumors]. / Hodnocení zánetlivé celulizace (tumor infiltrujících lymfocytu) u solidních nádoru.

BACKGROUND: The tumor microenvironment plays an important role in tumorigenesis and the tumor-host relationship. An important part of the tumor microenvironment is inflammatory infiltration. Its evaluation in solid tumors has prognostic meaning and appears also to be predictive of outcome, which is particularly important for predicting responses to immune checkpoint inhibitors. However, the methodology used to assess inflammatory infiltration is problematic, because it has been standardized only for certain types of tumors. OBJECTIVE: The present study provides an overview of current issues related to the evaluation of inflammatory cells (tumor infiltrating lymphocytes) in solid tumors, specifically in tumors of the breast, lung, head and neck, gastrointestinal tract, female genital tract, urogenital tract, brain, malignant mesothelioma, and malignant melanoma. Various methodologies for evaluation are mentioned, including the efforts that are being made to standardize these methodologies and the importance of immunophenotyping inflammatory infiltrates. With regard to clinical meaning, prognostic and predictive significance are also discussed. CONCLUSION: The evaluation of TILs in solid tumors often has predictive value; however, the results have been equivocal. There is also ambiguity about the predictive use of this marker. Despite all the methodological developments, which have resulted in the implementation of complicated technologies (image analysis, multiplex fluorescence immunohistochemistry, and mass spectrometry) for the evaluation of the various aspects of inflammatory infiltrates present in tumors, including their functional characteristics, there is still a need for standardization and development of inexpensive and universally available methodologies to enable the wide use of TIL evaluations in clinical settings. The recently proposed unified methodology may be used in all solid tumors and could help resolve one of the main limitations of the routine use of TIL, i.e., the inconsistent approach to assessment.Key words: solid tumors - tumor-infiltratig lymphocytes - inflammatory cells This work was supported by program of the Czech Ministry of Health No. RVO-VFN 64165 and AZV project No. 16-30954A, Charles University and OPPK (CZ.2.16/3.1.00/24509). The authors declare they have no potential conflicts of interest concerning drugs, products, or services used in the study. The Editorial Board declares that the manuscript met the ICMJE recommendation for biomedical papers.Submitted: 24. 9. 2017Accepted: 3. 10. 2017.

[Primary gastrointestinal lymphoma]. / Primární lymfomy zazívacího traktu z pohledu chirurga.

This article deals with a surgical approach to primary gastrointestinal lymphoma - a rare finding when compared to primary gastric carcinoma. The clinical findings, diagnosis and staging of the disease as well as various treatment methods and prognosis of the condition are discussed. As it is evident from the paper, the opinions of individual authors regarding this diagnosis may often differ considerably. Furthermore, this paper presents two separate case studies of surgical treatment for gastric lymphomas performed at our department in 2016. Case study 1 describes a surgical intervention for acute abdomen, where lymphoma was already diagnosed peroperatively. Case study 2 presents the case of a patient indicated for elective laparoscopic cholecystectomy with an unexpected finding of primary gallbladder lymphoma.Key words: primary gastrointestinal lymphoma - chemotherapy - surgical intervention - primary intestinal lymphoma - primary lymphoma of the gallbladder.

[Human prion diseases in the Czech Republic]. / Lidská prionová onemocnení v Ceské republice.

Human prion diseases are a group of very rare diseases with a unique pathogenesis and, due to an inauspicious prognosis and unavailability of therapy, with fatal consequences. The etiopathogenetic background is the presence of pathologically misfolded prion protein, highly resistant to denaturation, the aggregation and presence of which in the brain tissue causes irreversible neuronal damage. The most frequent prion disease in humans is Creutzfeldt-Jakob disease (CJD) which occurs in sporadic, hereditary/familial, or acquired/infectious/iatrogenic forms. A new form of CJD, variant CJD, is considered to be linked to dietary exposure to beef products from cattle infected with bovine spongiform encephalopathy (BSE) and to infection via blood transfusion. The clinical picture of these diseases is characterized by a rapidly progressing dementia, cerebellar and extrapyramidal symptoms, and rather specific MRI, EEG, and CSF findings. Clinically, the diagnosis is described as possible or probable prion disease and needs to be confirmed by neuropathological or immunological investigation of the brain tissue. Epidemiological data from the Czech Republic spanning the last decade are presented.

Differential expression and processing of matrix metalloproteinase 19 marks progression of gastrointestinal diseases.

Matrix metalloproteinases (MMPs), responsible for extracellular matrix remodelling and processing of numerous soluble and cell-surface proteins, appear to play important roles in pathogenesis of gastrointestinal diseases. MMPs influence migration of inflammatory cells, mucosal destruction, matrix deposition and degradation. In this study, we analysed the expression of MMP-19 in the main forms of gastrointestinal diseases including inflammatory bowel diseases (IBD) such as ulcerative colitis and Crohn's disease, and colorectal carcinoma. We identified prominent MMP-19 expression in unaffected areas of intestinal epithelia and macrophages but not in other cells or tissues. Abundant expression of MMP-19 was also found in the endothelium of blood and lymphatic vessels of inflamed intestinal tissue. High MMP-19 immunoreactivity was also associated with macrophages in inflamed areas and myenteric plexuses. In comparison to the intestinal epithelium, all these cell types and compartments appeared to express MMP-19 irrespective of the disease pathogenesis and progression. Intestinal epithelia exhibited striking differential immunoreactivity for MMP-19. While immunoreactivity of monoclonal antibody recognizing the propeptide domain declined in virtually all IBD and colorectal carcinoma samples, other polyclonal antibodies against the hinge region and propetide domain did not show such an obvious decrease. Additional Western blotting analysis revealed that the antibodies against MMP-19 recognize differently processed forms of this MMP. The disappearance of immunoreactivity of the monoclonal anti-propeptide domain antibody does not mean down-regulation of MMP-19, but processing of the immature form. As this processing likely leads to the activation of this MMP, the differential staining pattern may be an important sign of disease progression.

[Evaluation of safe resection margins in tumours of parenchymatous organs]. / Problematika stanovení bezpecných resekcních okraju u nádoru parenchymatózních orgánu

The definition of a safe surgical margin in tumours of parenchymatous organs has been the subject of frequent debates and a number of studies. This topic is not generally unified for parenchymatous organs and has many organ specifics. Moreover, there are still controversies in the diagnostic criteria and the definitions of positive resection margins, in indications of perioperative examinations of resection margins, and in the prognostic significance of margin involvement in different parenchymatous organs. The consensus in terminology and standardization of histopathological examination procedures is also very desirable across the diagnostic areas.

[Pulmonary mucormycosis caused by Rhizopus microsporus]. / Plicní mukormykóza vyvolaná Rhizopus microsporus.

We report a case of mycotic pneumonia in a patient with acute myeloblastic leukemia. Rhizopus microsporus was identified as an agent of mucormycosis and proven by microscopy and culture. The determination of the isolate was supported by molecular methods. Combined treatment with surgery (right-sided pneumonectomy) and systemic amphotericin B and posaconazole antifungal therapy was chosen. In this case, amphotericin B Neo-Sensitabs tablets gave false "resistant" results on Mueller-Hinton agar when using the disk diffusion test. There was a good correlation between the Etest (16 h) and the Sensititre YeastOne microplate (24 h) for amphotericin B.

[Neurodegenerative disorders: review of current classification and diagnostic neuropathological criteria]. / Neurodegenerativní onemocnení: prehled soucasné klasifikace a diagnostických neuropatologických kritérií

Neurodegenerative disorders are progressive diseases characterized by loss of specific neuronal populations followed by a clinical picture of a different neurodegenerative entity. Current classification of these diseases respects the names of the main pathophysiological processes involved in the groups of disorders. This is the reason why key proteins which represent neuropathological and biochemical hallmarks of diseases are found in their names. Neuropathological diagnosis is a synthesis of neurohistological changes in the brain and spinal cord and identification of pathological proteinaceous aggregates in neurons and/or glial cells. These inclusions are predominant diagnostic micromorphological and biochemical markers of disease. In the text, there is a brief summary of current knowledge about pathophysiology of neurodegenerations and diagnostic criteria for the most frequent entities.

PAR2 knock-out C57Bl6 mice as a model for evaluating metastases of cancer cells: pilot in vivo study of the metastatic potential of B16 melanoma in knock-out (PAR2-/-) animals.

Proteinase-activated receptor 2 (PAR-2) is a ubiquitous surface molecule. It belongs to the family of G protein-coupled receptors activated by site-specific proteolysis by trypsin. Altered function of PAR-2 has been described in different malignant tumours, both in vivo and in vitro. In the present study, we investigated differences of metastatic spread of B16 melanoma in knock-out animals compared with C57Bl6 mice. Knock-out mice B6.Cg-F2rl1(tm1Mslb)/J (PAR2-/-) and C57Bl6 controls were subcutaneously inoculated with the B16 melanoma tissue cell line. Fourteen days after inoculation, all primary tumours were removed and histopathologically analysed. After one month, animals in both group started to die. Autopsy showed metastatic spread of the melanoma to various organs in both groups. Our experiment confirmed growth and metastatic spread in both groups of mice. Excised tumours differed in volume and weight; average weight (0.62 g in PAR2-/- and 0.4 g in control animals). Metastatic spread was observed in both groups and reached 80 % in PAR2-/- and 50 % in control animals. While in control mice only lung metastases were observed, local tumour recurrence, renal and lung metastases were observed in PAR2-/- mice. The absence of functional PAR-2 could be an important factor influencing the growth and spread of melanoma in vivo, probably associated with tumour cell migration, invasiveness and metastasis formation.

[News in the classification of pulmonary adenocarcinomas and potential prognostic and predictive factors in non-small lung cancer]. / Novinky v klasifikaci adenokarcinomu plic a potenciální prognostické a prediktivní faktory u nemalobunecných plicních karcinomu.

Lung cancers are still divided into two major subgroups: small-cell and non-small cell lung cancer (NSCLC) irrespective of biological heterogeneity of NSCLC. It is a key task of the pathologist to provide an accurate classification of tumorous lesions to avoid the term NSCLC and to use it only in the vast minority of cases. Moreover, the most recent reclassification of pulmonary adenocarcinomas should be reflected in the standard biopsy protocol reporting. There is also an increasingly urgent need to provide high quality material for testing of the genetic characteristics of NSCLC, especially the presence and functional status of the EGFR receptor (epidermal growth factor receptor), as well as other potential prognostic markers. The requirement for the quality and swiftness of diagnosis puts major emphasis on the close multidisciplinary collaboration with the central role of a specialized pathologist, who coordinates the differential-diagnostic procedure. This in turn implies the necessity of accounting for the increasing financial burden of diagnostic departments.

Relationship between ALS and the degree of cognitive impairment, markers of neurodegeneration and predictors for poor outcome. A prospective study.

INTRODUCTION: Amyotrophic lateral sclerosis (ALS) is a common neurodegenerative disease affecting motor neurons and may be associated with impaired cognition. Reliable prognostic factors for ALS patients are still missing. METHODS: We prospectively included 67 patients, 42 women and 25 men, with clinically defined ALS. The disease severity was assessed and the patients underwent SPECT, lumbar puncture with determination of tau, hyperphosporylated tau (p-tau) and beta-amyloid and a detailed neuropsychological assessment using a standardized test battery. In patients who died, a detailed neuropathologic evaluation was performed. RESULTS: The mean survival duration was 26.8 months. The delay between the first signs and confirmation of the diagnosis was 12.75 months. Cognitive impairment did not have an impact on the evolution of the disease. There was no correlation between neuropsychological and SPECT findings. Higher age at onset, more pronounced handicap and elevated beta-amyloid in the CSF were associated with shorter survival times. In brain tissue from nine of the deceased patients with ALS and dementia, all showed signs of comorbidity, six had hallmarks of frontotemporal lobar degeneration (FTLD) and three showed Alzheimer disease pathology. Brain tissues form 11 deceased ALS patients who did not show signs of dementia, had only changes compatible with a diagnosis of motor neuron disease. CONCLUSION: In our prospective study, age, disease severity and CSF beta-amyloid levels taken together were a risk factor suggesting shorter survival times. Dementia is relatively frequent in ALS and may be a consequence of either FTLD or result from co-existing Alzheimer disease.

[Merkel cell carcinoma--immunohistochemical study in a group of 11 patients]. / Karcinom z Merkelových bunek--imunohistologická studie v souboru 11 pacientu.

The aim of our work was to confirm an immunohistochemical profile of routine markers of epithelial and neuroendocrine differentiation in eleven cases of Merkel cell carcinoma, as well as to study the expression of two markers of early phases of neuronal differentiation, namely reelin and class III beta-tubulin, markers which have not yet been studied in Merkel cell carcinomas. In all the investigated tumours the characteristic "dot-like" pattern of cytokeratin 20 immunoexpression, as well as negative immunostaining for cytokeratin 7 and thyroid transcription factor 1 (TTF-1) were disclosed; all the tumours showed neuroendocrine differentiation, expressing either neuron specific enolase (NSE) or chromogranin A(CgA), or both. An interesting finding was observed when the anti-cytokeratin monoclonal antibody MNF 116 was used. The characteristic "dot-like" pattern was detected in high proportion of tumours, including two samples of local recurrence of one of the carcinomas, where neoplastic cells have lost the expression of cytokeratin 20. The majority (91%) of Merkel cell carcinomas included in our group showed positive immunodetection of class III beta-tubulin when TU-20 antibody was used, while TuJ-1 immunostaining was surprisingly negative in all the investigated tumours. Detection of reelin was negative in almost all the studied Merkel cell carcinomas except for cases, where neoplastic cells revealed weak focal immunostaining in a minor portion of neoplastic cells.

[Immunohistochemical detection of TTF-1 in intraoperative bioptic samples of adenocarcinoma of the lung: a year-long experience]. / Imunohistochemický prukaz TTF-1 v peroperacních Bioptických vzorcích plicních adenokarcinomu: rocní zkusenosti.

The thyroid transcription factor 1 (TTF-1) is a highly sensitive and specific marker of adenocarcinomas of pulmonary origin in differential diagnosis of solitary pulmonary nodules. Positivity of TTF-1 as a marker of primary pulmonary tumor could have a very high impact on surgical treatment strategy. From known protocols we developed the method of immunohistochemical investigation of intraoperative bioptic samples from frozen section lasting about 15 minutes. During last year, we applied this method on 30 cases of intraoperative bioptic samples. All investigated cases were verified by immunohistochemical examination from formalin-fixed and paraffin-embedded definite tissue samples. With the exception of two samples in which the result was inconclusive from both frozen and fixed tissue, all other samples revealed the same result. Our experience demonstrates that intraoperative immunohistochemical investigation of TTF-1 in proper consequences could be a very useful tool for routine practice.

Early onset Alexander disease: a case report with evidence for manifestation of the disorder in neurohypophyseal pituicytes.

We report the first case of Alexander disease diagnosed and published in the region of former Czechoslovakia. The case was characterized by early (late infantile) onset, the absence of megacephaly but with extensive internal hydrocephaly, despite a patent aqueduct. Neuropathology revealed severe depletion ofoligodendroglia and myelin, loss of axons, prominent astrocytosis with massive intracellular, dense globular GFAP aggregates which differed from typical Rosenthal fibers. Additionally, many large aggregates of GFAP were located extracellularly. Globular GFAP aggregates were also identified in neurohypophyseal pituicytes. DNA analysis disclosed a heterozygous mutation c.1117G>A in the GFAP, which is predicted to lead to the amino acid exchange p.Glu-373Lys (E373K) in the C-terminal tail of the GFAP protein. The parents and a healthy sister did not show any variation in GFAP in somatic cells.

Amyotrophic lateral sclerosis and Alzheimer's disease--clinical and neuropathological considerations in two cases.

Amyotrophic lateral sclerosis (ALS) may be accompanied by cognitive impairment; when present, it is mainly in the form of frontotemporal impairment. We report on two cases with clinically defined ALS that subsequently developed dementia. Neuropathological examination showed not only the typical neuropathological hallmarks characteristic of ALS but, surprisingly, also showed neurofibrillary tangles and neuritic plaques in sufficient numbers to fulfill the diagnostic criteria of definite Alzheimer's disease.