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Pathology, Research and Practice Nov 1989The principles behind grading histological samples by any method describing them is outlined. The estimation of the variation of measurement allows the number of falsely... (Review)
Review
The principles behind grading histological samples by any method describing them is outlined. The estimation of the variation of measurement allows the number of falsely graded cases to be estimated, and thus makes it possible to compare grading methods in respect to their sensitivity, specificity, and efficiency. The approach is especially suitable for situations in which measurements are made on histological sections, but can also be applied in traditional subjective grading. The approach also makes it possible to estimate the grading performance by such methods as DNA-cytometry, flow cytometry, immunohistochemistry, and nucleic acid in situ hybridisation.
Topics: Humans; Neoplasms; Pathology, Clinical; Precancerous Conditions; Reproducibility of Results; Sensitivity and Specificity
PubMed: 2696940
DOI: 10.1016/S0344-0338(89)80189-X -
Diagnostic Molecular Pathology : the... Mar 2009Diagnosis of sarcoma increasingly relies on identifying genetic defects using modern molecular technologies. Each analytic method has unique advantages and specimen... (Review)
Review
Diagnosis of sarcoma increasingly relies on identifying genetic defects using modern molecular technologies. Each analytic method has unique advantages and specimen requirements that should be considered when allocating tissue for downstream testing. Karyotype on fresh tissue represents a genome-wide screen of gross chromosomal alterations, whereas fluorescence in situ hybridization and polymerase chain reaction detect specific defects that are characteristic of a given tumor type such as t(11;22) EWSR1-FLI1 in Ewing family tumors, t(X;18) SS18-SSX1 in synovial sarcoma, t(2;13) PAX3-FOXO1A in alveolar rhabdomyosarcoma, and MYCN gene amplification in neuroblastoma. Identifying a clonal genetic defect also provides a tumor marker that could help stage the extent of spread of the neoplasm or monitor the efficacy of therapy. In research laboratories, array-based methods identify genes and biochemical pathways contributing to tumor growth and maintenance, opening avenues for pharmacogenetic tests that predict which therapy is likely to overcome the biochemical defects with minimal toxicity. Array-based discoveries are also spurring validation of smaller test panels that rely on conventional technologies such as immunohistochemistry and reverse transcription polymerase chain reaction. The pathologist's expertise is critical in: (1) consulting with clinicians about specimen collection and handling; (2) preserving tissue for immediate testing and for any downstream testing that is indicated once morphology and immunophenotype are known; (3) performing tests that maximize outcome on the basis of the strengths and limitations of each assay in each available specimen type; and (4) conveying results to the rest of the healthcare team using proper gene nomenclature and interpreting the findings in a way that facilitates optimal clinical management.
Topics: Biomarkers, Tumor; Humans; In Situ Hybridization; Karyotyping; Microarray Analysis; Pathology; Polymerase Chain Reaction; Reverse Transcriptase Polymerase Chain Reaction; Sarcoma
PubMed: 19214114
DOI: 10.1097/PDM.0b013e318181fa05 -
Toxicologic Pathology 2000Teased-fiber technique is the best approach for studying peripheral myelinated nerve fibers in their continuity. It enables the assessment of size of myelin segments... (Review)
Review
Teased-fiber technique is the best approach for studying peripheral myelinated nerve fibers in their continuity. It enables the assessment of size of myelin segments formed by Schwann cells and characterization of pathologic changes affecting the internodia, the paranodal regions, and the invested axons. Fiber teasing is performed on prestained proximodistally oriented portions of peripheral nerves. Specimens about 10 mm long are stained for 24-48 hours in Sudan black and then transferred to glycerin, where, using a pair of fine forceps and a stereomicroscope, they are separated into smaller fiber bundles from which single fibers are isolated. The work is performed on a glass slide with an adhesive surface (albuminized or "superfrost"), on which the fibers are placed in strict proximodistal orientation. Following drying in an oven, the slides are mounted with glycerin-gelatine (same as used for frozen sections). The changes, when present, can usually be recognized during the preparation, but fibers are reexamined and changes confirmed in mounted slides. Photographic reconstruction of the fibers facilitates their assessment and enables the documentation of findings. The teased-fiber technique is auxiliary to histopathology, and to limit the workload and save costs, it can be performed on only a few specimens selected for better characterization of changes recognized or suspected in tissue sections. In particular, segmental demyelination and early stages of Wallerian or secondary axonal degeneration can be recognized in teased fibers. Segmental demyelination is characterized by loss of fully myelinated segments and their replacement by newly formed short and thin segments, remyelinating the preserved axon. The early stage of secondary axonal degeneration is recognized by formation of ovoidal fiber fragments in the midinternodal region.
Topics: Animals; Axons; Demyelinating Diseases; Humans; Nerve Fibers, Myelinated; Pathology; Peripheral Nerves
PubMed: 10668997
DOI: 10.1177/019262330002800114 -
Clinical & Translational Oncology :... Nov 2018Cancer of unknown primary (CUP) is defined as a heterogeneous group of tumours that present with metastasis, and in which attempts to identify the original site have... (Review)
Review
Cancer of unknown primary (CUP) is defined as a heterogeneous group of tumours that present with metastasis, and in which attempts to identify the original site have failed. They differ from other primary tumours in their biological features and how they spread, which means that they can be considered a separate entity. There are several hypotheses regarding their origin, but the most plausible explanation for their aggressiveness and chemoresistance seems to involve chromosomal instability. Depending on the type of study done, CUP can account for 2-9% of all cancer patients, mostly 60-75 years old. This article reviews the main clinical, pathological, and molecular studies conducted to analyse and determine the origin of CUP. The main strategies for patient management and treatment, by both clinicians and pathologists, are also addressed.
Topics: Aged; Consensus; Humans; Medical Oncology; Middle Aged; Neoplasms, Unknown Primary; Pathology, Clinical; Societies, Medical; Spain
PubMed: 29808414
DOI: 10.1007/s12094-018-1899-z -
American Journal of Clinical Pathology Oct 1996In this cost-conscious era, quality assessment activities in anatomic pathology are required not only to assure that quality practices result in satisfaction of... (Review)
Review
In this cost-conscious era, quality assessment activities in anatomic pathology are required not only to assure that quality practices result in satisfaction of accreditation standards but also to focus quality management to improve services in an economically competitive manner. Selected high yield monitoring activities that provide comparison to reference databases for benchmarking performance and adoption of practice variables effective in the best laboratories are recommended.
Topics: Autopsy; Health Care Costs; Pathology, Clinical; Pathology, Surgical; Quality Assurance, Health Care; Quality Control
PubMed: 8853049
DOI: No ID Found -
Archives of Pathology & Laboratory... May 2009The use of DNA- and RNA-based tests continues to grow for applications as varied as inherited disease, infectious disease, cancer, identity testing, human leukocyte... (Review)
Review
CONTEXT
The use of DNA- and RNA-based tests continues to grow for applications as varied as inherited disease, infectious disease, cancer, identity testing, human leukocyte antigen typing, and pharmacogenetics. Progress is driven in part by the huge growth in knowledge about the molecular basis of disease coupled with advancements in technologic capabilities. In addition to requirements for clinical utility, every molecular test also may have limitations that must be carefully considered before clinical implementation. Analytic and clinical performance characteristics as well as test limitations are established and documented through the process of test validation.
OBJECTIVE
To describe the established principles of test validation, along with relevant regulations in the United States, in order to provide a rational approach to introducing molecular tests into the clinical laboratory.
DATA SOURCES
PubMed review of published literature, published guidelines, and online information from national and international professional organizations.
CONCLUSIONS
These resources and recommendations provide a framework for validating clinical tests.
Topics: Humans; Molecular Biology; Molecular Diagnostic Techniques; Pathology, Clinical; United States; Validation Studies as Topic
PubMed: 19415949
DOI: 10.5858/133.5.743 -
Journal of Cutaneous Pathology Jun 2018The objective of our study was to establish a detailed photomicrographing protocol for pathologists and dermatopathologists using standard overhead camera and image...
The objective of our study was to establish a detailed photomicrographing protocol for pathologists and dermatopathologists using standard overhead camera and image editing packages. Through a trial-and-error approach we devised a series of steps that comprise our photomicrographing protocol. Descriptive and interpretive data analyses were performed to highlight how each step improves tinctorial quality of digital photomicrographs.
Topics: Cell Phone; Dermatology; Humans; Image Processing, Computer-Assisted; Pathology; Photomicrography; Software
PubMed: 29484692
DOI: 10.1111/cup.13136 -
Molecular Oncology Jun 2014Tumor evaluation in pathology is more and more based on a combination of traditional histopathology and molecular analysis. Due to the rapid development of new cancer... (Review)
Review
Tumor evaluation in pathology is more and more based on a combination of traditional histopathology and molecular analysis. Due to the rapid development of new cancer treatments that specifically target aberrant proteins present in tumor cells, treatment decisions are increasingly based on the molecular features of the tumor. Not only the number of patients eligible for targeted precision medicine, but also the number of molecular targets per patient and tumor type is rising. Diagnostic molecular pathology, the discipline that determines the molecular aberrations present in tumors for diagnostic, prognostic or predictive purposes, is faced with true challenges. The laboratories have to meet the need of comprehensive molecular testing using only limited amount of tumor tissue, mostly fixed in formalin and embedded in paraffin (FFPE), in short turnaround time. Choices must be made for analytical methods that provide accurate, reliable and cost-effective results. Validation of the test procedures and results is essential. In addition, participation and good performance in internal (IQA) and external quality assurance (EQA) schemes is mandatory. In this review, we critically evaluate the validation procedure for comprehensive molecular tests as well as the organization of quality assurance and assessment of competence of diagnostic molecular pathology laboratories within Europe.
Topics: Europe; High-Throughput Screening Assays; Humans; Laboratories; Molecular Diagnostic Techniques; Neoplasms; Pathology, Molecular; Quality Control; Reproducibility of Results
PubMed: 24704265
DOI: 10.1016/j.molonc.2014.03.004 -
Pathology Jun 2002The New South Wales (NSW) Tissue Resource Centre (TRC) has been set up to provide Australian and international researchers with fixed and frozen brain tissue from cases... (Review)
Review
The New South Wales (NSW) Tissue Resource Centre (TRC) has been set up to provide Australian and international researchers with fixed and frozen brain tissue from cases that are well characterised, both clinically and pathologically, for projects related to neuropsychiatric and alcohol-related disorders. A daily review of the Department of Forensic Medicine provides initial information regarding a potential collection. If the case adheres to the strict inclusion criteria, the pathologist performing the postmortem examination is approached regarding retention of the brain tissue. The next of kin of the deceased is then contacted requesting permission to retain the brain for medical research. Cases are also obtained through donor programmes, where donors are assessed and consent to donate their brain during life. Once the brain is removed at autopsy, the brain is photographed, weighed and the volume determined, the brainstem and cerebellum are removed. The two hemispheres are divided, one hemisphere is fresh frozen and one fixed (randomised). Prior to freezing, the hemisphere is sliced into 1-cm coronal slices and a set of critical area blocks is taken. All frozen tissues are kept bagged at -80 degrees C. The other hemisphere is fixed in 15% buffered formalin for 2 weeks, embedded in agar and sliced at 3-mm intervals in the coronal plane. Tissue blocks from these slices are used for neuropathological analysis to exclude any other pathology. The TRC currently has 230 cases of both fixed and frozen material that has proven useful in a range of techniques in many research projects. These techniques include quantitative analyses of brain regions using neuropathological, neurochemical, neuropharmacological and gene expression assays.
Topics: Autopsy; Brain; Brain Diseases; Humans; New South Wales; Pathology; Specimen Handling; Tissue Banks
PubMed: 12109781
DOI: 10.1080/00313020220131260 -
Analytical Cellular Pathology... 2012In pathology, histological examination of the "gold standard" to diagnose various diseases. It has contributed significantly toward identifying the abnormalities in... (Review)
Review
In pathology, histological examination of the "gold standard" to diagnose various diseases. It has contributed significantly toward identifying the abnormalities in tissues and cells, but has inherent drawbacks when used for fast and accurate diagnosis. These limitations include the lack of in vivo observation in real time and sampling errors due to limited number and area coverage of tissue sections. Its diagnostic yield also varies depending on the ability of the physician and the effectiveness of any image guidance technique that may be used for tissue screening during excisional biopsy. In order to overcome these current limitations of histology-based diagnostics, there are significant needs for either complementary or alternative imaging techniques which perform non-destructive, high resolution, and rapid tissue screening. Optical coherence tomography (OCT) is an emerging imaging modality which allows real-time cross-sectional imaging with high resolutions that approach those of histology. OCT could be a very promising technique which has the potential to be used as an adjunct to histological tissue observation when it is not practical to take specimens for histological processing, when large areas of tissue need investigating, or when rapid microscopic imaging is needed. This review will describe the use of OCT as an image guidance tool for fast tissue screening and directed histological tissue sectioning in pathology.
Topics: Animals; Biopsy; Diagnostic Imaging; Humans; Pathology; Tomography, Optical Coherence
PubMed: 22133731
DOI: 10.3233/ACP-2011-0047