Light Microscopic Diagnosis Research Articles

What factors influence cellular pathologists' confidence in case reporting?

Histopathology is a challenging interpretive discipline, and the level of confidence a pathologist has in their diagnosis is known to vary, which is conveyed descriptively in pathology reports. There has been little study to accurately quantify pathologists' diagnostic confidence or the factors that influence it. In this study involving sixteen pathologists from six NHS trusts, we assessed diagnostic confidence across multiple variables and four specialties. Each case was reported by four pathologists, with each pathologist reporting each case twice (on light microscopy (LM) and digital pathology (DP)). For each diagnosis, pathologists recorded their confidence on a 7-point Likert scale. This provided 16,187 diagnoses and associated confidence scores for analysis. All variables investigated were found to be significantly predictive of diagnostic confidence, except level of pathologist experience. Confidence was lower for difficult to report cases, cases where there was inter- and intra-pathologist variation in the diagnosis, and cases where the pathologist made an incorrect diagnosis. Confidence was higher, although nominally, for LM diagnoses than DP (rate ratio 1.09 (95% CI 1.01-1.18), p = 0.035), although results indicate pathologists are confident to report on DP. Lowest confidence scores were seen in areas of known diagnostic complexity and cases with quality issues. High confidence in incorrect diagnoses were almost invariably attributed to interpretive diagnostic differences which occurred across both rare and common lesions. The results highlight the value of external quality control schemes and the benefits of selective peer review when reporting.

Thrombotic Microangiopathy in the Renal Allograft: Results of the TMA Banff Working Group Consensus on Pathologic Diagnostic Criteria.

The Banff community summoned the TMA Banff Working Group to develop minimum diagnostic criteria (MDC) and recommendations for renal transplant TMA (Tx-TMA) diagnosis, which currently lacks standardized criteria. Using the Delphi method for consensus generation, 23 nephropathologists (panelists) with >3years of diagnostic experience with Tx-TMA were asked to list light, immunofluorescence, and electron microscopic, clinical and laboratory criteria and differential diagnoses for Tx-TMA. Delphi was modified to include 2 validations rounds with histological evaluation of whole slide images of 37 transplant biopsies (28 TMA and 9 non-TMA). Starting with 338 criteria in R1, MDC were narrowed down to 24 in R8 generating 18 pathological, 2 clinical, 4 laboratory criteria, and 8 differential diagnoses. The panelists reached a good level of agreement (70%) on 76% of the validated cases. For the first time in Banff classification, Delphi was used to reach consensus on MDC for Tx-TMA. Phase I of the study (pathology phase) will be used as a model for Phase II (nephrology phase) for consensus regarding clinical and laboratory criteria. Eventually in Phase III (consensus of the consensus groups) and the final MDC for Tx-TMA will be reported to the transplantation community.

Malaria transmission structure in the Peruvian Amazon through antibody signatures to Plasmodium vivax.

BackgroundThe landscape of malaria transmission in the Peruvian Amazon is temporally and spatially heterogeneous, presenting different micro-geographies with particular epidemiologies. Most cases are asymptomatic and escape routine malaria surveillance based on light microscopy (LM). Following the implementation of control programs in this region, new approaches to stratify transmission and direct efforts at an individual and community level are needed. Antibody responses to serological exposure markers (SEM) to Plasmodium vivax have proven diagnostic performance to identify people exposed in the previous 9 months.MethodologyWe measured antibody responses against 8 SEM to identify recently exposed people and determine the transmission dynamics of P. vivax in peri-urban (Iquitos) and riverine (Mazán) communities of Loreto, communities that have seen significant recent reductions in malaria transmission. Socio-demographic, geo-reference, LM and qPCR diagnosis data were collected from two cross-sectional surveys. Spatial and multilevel analyses were implemented to describe the distribution of seropositive cases and the risk factors associated with exposure to P. vivax.Principal findingsLow local transmission was detected by qPCR in both Iquitos (5.3%) and Mazán (2.7%); however, seroprevalence indicated a higher level of (past) exposure to P. vivax in Mazán (56.5%) than Iquitos (38.2%). Age and being male were factors associated with high odds of being seropositive in both sites. Higher antibody levels were found in individuals >15 years old. The persistence of long-lived antibodies in these individuals could overestimate the detection of recent exposure. Antibody levels in younger populations (<15 years old) could be a better indicator of recent exposure to P. vivax.ConclusionsThe large number of current and past infections detected by SEMs allows for detailed local epidemiological analyses, in contrast to data from qPCR prevalence surveys which did not produce statistically significant associations. Serological surveillance will be increasingly important in the Peruvian Amazon as malaria transmission is reduced by continued control and elimination efforts.

Association of Proliferative Activity in Invasive Ductal Carcinoma Breast in Pakistani Population.

Background:Personalized medicine has played very important role in management of breast cancer. Proliferative index is one among the prognostic and predictive factor but unfortunately due to varied reports , no definite consensus and routine medical practice has been approved for it. The objective of the study is to observe the association of Ki-67 index using St. Gallen Conference criteria in invasive ductal carcinoma breast in Pakistani Population. Methods:Eighty-three patients with confirmed light microscopic diagnosis of primary invasive ductal carcinoma were recruited in this prospective study . Expression of Ki67 was determined by classifying as low (<15%) and high (>15%) Ki67 in tumour. Statistical analysis was performed to observe the association of Ki-67 with clinicopathological parameters and molecular group (i.e., Luminal A, Luminal B, Her2 enriched and triple negative). Results:Out of 83 patients, 73.5% of patients showed >15% Ki67 (p value <0.001). High expression of Ki 67 (>15%) was observed in 3.6%, 21.7% and 48.2 % of Nottingham grade I, II and III (p value=0.017) respectively. Among molecular group, high expression of Ki67 was observed 20.5% in Luminal A, 9.6% in Luminal B, 15.7% in Her2 enriched and 27.7% in triple negative groups (p= 0.017). There was no significant association observed in expression of Ki 67 among lymph node stage, tumour stage and Nottingham prognostic index. Conclusion:Higher Ki-67 reactivity is usually associated with higher-grade morphology of tumour. It can act as an independent predictor in assessment of tumour behavior. However, larger validation clinical studies are still required for confirmation of its importance and for routine practice.

Role of Ultrastructural Study in the Diagnosis of Medical Renal Diseases: A Tertiary Medical Center Experience and Review of the Literature

The 20th century unfolded many mysteries regarding renal pathology with the advent of ancillary techniques such as immunofluorescence (IF) and electron microscopy (EM) studies. EM plays a major role in confirming the routine and IF findings or may uncover new and unsuspected features. The aim of the study is to elucidate the role of ultrastructural findings in patients with medical kidney diseases on whom kidney biopsy was performed at the American University of Beirut Medical Center, between November 2018 and June 2019. A total of 188 renal biopsies were examined during the study period. EM confirmed the light microscopy diagnosis in 54% of the cases while completely changed the diagnosis in 23% of the cases. In 23% of the sample, EM provided additional features and a secondary diagnosis. Our study emphasizes the important diagnostic role of EM and its significance, particularly in minimal change disease, basement membrane abnormalities, and glomerulopathies.

A New Modified Staining Technique for Demonstration of Prototheca Spp. Algae on Paraffin Sections First Record.

The environmental Prototheca algae under certain condition are responsible for protothecosis infection in animal and human. The detail pathology and pathogenesis of this type of infection was unclear. Light microscopic diagnosis of Prototheca spp. algae is difficult with the use of routine histologic H&E stains. The specific stainsof fungusas periodic acid–Schiff (PAS) or Gomori Methenamine silver (GMS) were used and these stainsare not enough for examination of algae. A new modified staining method wasprepared. The main chemical constituents were Chromotrope2R, Aniline blueand phosphotungestic acid. The new stain gives very sharp affinity for staining of intra and extra cellular of Prototheca spp.microalgae and sporangium in different stages of maturation. The new stain will help the pathologist tostudy the pathology and pathogenesis of this type of pathogenic algae and considered the first specific stain for algae in tissue section.

A validation study of whole slide imaging for primary diagnosis of lymphoma.

Whole slide imaging (WSI) is being increasingly used worldwide. Although previous studies have asserted the validity of WSI diagnosis, they have primarily targeted only small specimens and excluded cases requiring immunohistochemistry or special staining, such as lymphoma. The purpose of this study was to evaluate the accuracy of WSI diagnosis of lymphoma, for which 240 biopsies and resections of lymphoma cases were selected from the study set of lymphomas. All slides including H&E, immunohistochemical and special staining were digitized using a WSI image scanner. An experienced pathologist performed the WSI diagnoses, which were compared with original diagnoses based on light microscopic examinations. Discrepancy between the two interpretations were classified into three categories: concordance, minor discrepancy (no clinical significance), and major discrepancy (with clinical significance). Overall concordance between the light microscopic and WSI diagnosis was found in 223 cases (92.92%; 95%CI = 88.90-95.82), minor discrepancy in fifteen (6.25%; 95%CI = 3.54-10.10), and major discrepancy in two (0.83%; 95%CI = 0.10-2.98). Diagnosis of lymphoma using WSI appeared to be mostly accurate, suggesting that WSI may be a reliable technology for the diagnosis of lymphoma.

Validation of a whole-slide image-based teleconsultation network.

Most validation studies on digital pathology diagnostics have been performed in single institutes. Because rapid consultation on cases with extramural experts is one of the most important uses for digital pathology laboratory networks, the aim of this study was to validate a whole-slide image-based teleconsultation network between three independent laboratories. Each laboratory contributed 30 biopsies and/or excisions, totalling 90 specimens (776 slides) of varying difficulty and covering a wide variety of organs and subspecialties. All slides were scanned centrally at ×40 scanning magnification and uploaded, and subsequently assessed digitally by 16 pathologists using the same image management system and viewer. Each laboratory was excluded from digital assessment of their own cases. Concordance rates between the two diagnostic modalities (light microscopic versus digital) were compared. Loading speed of the images, zooming latency and focus quality were scored. Leaving out eight minor discrepancies without any clinical significance, the concordance rate between remote digital and original microscopic diagnoses was 97.8%. The two cases with a major discordance (for which the light microscopic diagnoses were deemed to be the better ones) resulted from a different interpretation of diagnostic criteria in one case and an image quality issue in the other case. Average scores for loading speed of the images, zooming latency and focus quality were 2.37 (on a scale up to 3), 2.39 (scale up to 3) and 3.06 (scale up to 4), respectively. This validation study demonstrates the suitability of a teleconsultation network for remote digital consultation using whole-slide images. Such networks may contribute to faster revision and consultation in pathology while maintaining diagnostic standards.

A Trial Study of Static Telepathology in Iran.

Static telepathology is one of the telepathology methods, in which the captured images of the slides are transmitted for consultation at a later time. This study aimed to compare the diagnostic accuracy of the conventional pathology and static telepathology systems. Eighty-two cases that had been selected randomly from 4 pathology centers in the city of Kerman were diagnosed by a pathologist, first based on light microscopy and then after 2 months based on static images (2 images per case) captured by a Nikon 50i microscopic camera. The images were sent to the pathologist via e-mail. The diagnostic accuracy of the telepathology system was calculated. The light microscopic diagnoses were concordant with the telepathologic diagnoses in 71 of 82 reviewed cases. Different diagnoses of 7 cases were due to the images captured from the inappropriate location of the slides. The diagnostic accuracy of the telepathology system was 86.5%. The results of this study showed that static telepathology is very accurate and can be widely used in Iran. However, efficient implementation and use of telepathology require paying attention to different issues such as educational, legal, ethical, financial, and security and observance of the standards related to this field.

A light and scanning electron microscopic diagnosis of leaf epidermal morphology and its systematic implications in Dryopteridaceae: Investigating 12 Pakistani taxa

Dryopteris and Polystichum are the 2 complex taxonomic genera of Dryopteridaceae. The comparative foliar epidermal anatomy of 12 species of both genera from Pakistan were studied using standard protocols of light microscopy (LM) and scanning electron microscopy (SEM). The objective of which was systematic comparison and investigation to elucidate the taxonomic importance of foliar micromorphology, which may be useful to taxonomists for identifying complex Dryopteridaceae taxa. Principal component analysis and UPGMA clustering analysis were performed to test the validity of leaf anatomical features as method of separating species and genera. The foliar epidermal anatomy described here is a good source of taxonomic characters in both groups that can help genera and species delimitation. This is the first report on leaf micromorphology in most of these species. Observation of foliar anatomy showed that stomata are only present on the abaxial surface; i.e., leaves of all species are hypostomatic. The shapes of epidermal cells in all studied species are irregular. The anticlinal walls are strongly lobed, irregular wavy and elongated wavy. However, substantial variation in epidermal cell size and other stomatal features were observed on both upper and lower surfaces in all investigated species. Two types of stomata were observed in all studied species. The presence of polocytic stomata in Dryopteris and staurocytic stomata in Polystichum are the important characters for the segregation of these genera. Elongate elliptic stomatal shape, narrow kidney shaped guard cells and broad elliptic shaped stomatal pores are diagnostic for all five species of Dryopteris selected. On the other hand, size and number of epidermal cells, lobes per cell, stomatal size, subsidiary cell size, stomatal pore size and stomatal index are the key features for species differentiation in Polystichum. An identification key was developed in order to apply the foliar anatomical characters in the discrimination of the species studied.

Complete Routine Remote Digital Pathology Services

Background: Validation studies in digital pathology addressed so far diverse aspects of the routine work. We aimed to establish a complete remote digital pathology service. Methods: Altogether 2295 routine cases (8640 slides) were reported in our studies on digital versus microscopic diagnostics, remote reporting, diagnostic time, fine-needle aspiration cytology (FNAC) clinics, frozen sections, and diagnostic sessions with residents. The same senior pathologist was involved in all studies. Slides were scanned by ScanScope AT Turbo (Aperio). Digital images were accessed through the laboratory system (LS) on either 14” laptops or desktop computers with double 23” displays for the remote and on-site digital reporting. Larger displays were used when available for remote reporting. First diagnosis was either microscopic, digital, or remote digital only (6 months washout period). Both diagnoses were recorded separately and compared. Turnaround was measured from the registration to sign off or scanning to diagnosis. A diagnostic time was measured from the point slides were made available to the point of diagnosis or additional investigations were necessary, recorded independently in minutes/session, and compared. Jabber Video (Cisco) and Lync (Microsoft) were interchangeably used for the secure, video supervision of activities. Mobile phone, broadband, broadband over Wi-Fi, and mobile broadband were tested for internet connections. Nine autopsies were performed remotely involving three staff pathologists, one autopsy technician, and one resident over the secure video link. Remote and on-site pathologists independently interpreted and compared gross findings. Diverse benefits and technical aspects were studied using logs or information recorded in LS. Satisfaction surveys on diverse technical and professional aspects of the studies were conducted. Results: The full concordance between digital and light microscopic diagnosis was 99% (594/600 cases). A minor discordance, without clinical implications, was 1% (6/600 cases). The instant upload of digital images was achieved at 20 Mbps. Deference to microscopic slides and rescanning were under 1%. Average turnaround was shorter and percentage of cases reported up to 3 days higher for remote digital reporting. Larger displays improved the most user experience at magnifications over ×20. A digital diagnostic time was shorter than microscopic in 13 sessions. Four sessions with shorter microscopic diagnostic time included more cases requiring extensive use of magnifications over ×20. Independent interpretations of gross findings between remote and on-site pathologists yielded full agreement in the remote autopsies. Delays in reporting of frozen sections and FNAC due to scanning were clinically insignificant. Satisfaction levels with diverse technical and/or professional aspects of all studies were high. Conclusions: Complete routine remote digital pathology services are found feasible in hands of experienced staff. The introduction of digital pathology has improved provisions and organizations of our pathology services in histology, cytology, and autopsy including teaching and interdepartmental collaboration.

High prevalence of very-low Plasmodium falciparum and Plasmodium vivax parasitaemia carriers in the Peruvian Amazon: insights into local and occupational mobility-related transmission

BackgroundThe incidence of malaria due both to Plasmodium falciparum and Plasmodium vivax in the Peruvian Amazon has risen in the past 5 years. This study tested the hypothesis that the maintenance and emergence of malaria in hypoendemic regions such as Amazonia is determined by submicroscopic and asymptomatic Plasmodium parasitaemia carriers. The present study aimed to precisely quantify the rate of very-low parasitaemia carriers in two sites of the Peruvian Amazon in relation to transmission patterns of P. vivax and P. falciparum in this area.MethodsThis study was carried out within the Amazonian-ICEMR longitudinal cohort. Blood samples were collected for light microscopy diagnosis and packed red blood cell (PRBC) samples were analysed by qPCR. Plasma samples were tested for total IgG reactivity against recombinant PvMSP-10 and PfMSP-10 antigens by ELISA. Occupation and age 10 years and greater were considered surrogates of occupation-related mobility. Risk factors for P. falciparum and P. vivax infections detected by PRBC-qPCR were assessed by multilevel logistic regression models.ResultsAmong 450 subjects, the prevalence of P. vivax by PRBC-PCR (25.1%) was sixfold higher than that determined by microscopy (3.6%). The prevalence of P. falciparum infection was 4.9% by PRBC-PCR and 0.2% by microscopy. More than 40% of infections had parasitaemia under 5 parasites/μL. Multivariate analysis for infections detected by PRBC-PCR showed that participants with recent settlement in the study area (AOR 2.1; 95% CI 1.03:4.2), age ≥ 30 years (AOR 3.3; 95% CI 1.6:6.9) and seropositivity to P. vivax (AOR 1.8; 95% CI 1.0:3.2) had significantly higher likelihood of P. vivax infection, while the odds of P. falciparum infection was higher for participants between 10 and 29 years (AOR 10.7; 95% CI 1.3:91.1) and with a previous P. falciparum infection (AOR 10.4; 95% CI 1.5:71.1).ConclusionsThis study confirms the contrasting transmission patterns of P. vivax and P. falciparum in the Peruvian Amazon, with stable local transmission for P. vivax and the source of P. falciparum to the study villages dominated by very low parasitaemia carriers, age 10 years and older, who had travelled away from home for work and brought P. falciparum infection with them.

The Empirical Foundations of Telepathology: Evidence of Feasibility and Intermediate Effects.

Telepathology evolved from video microscopy (i.e., "television microscopy") research in the early 1950s to video microscopy used in basic research in the biological sciences to a basic diagnostic tool in telemedicine clinical applications. Its genesis can be traced to pioneering feasibility studies regarding the importance of color and other image-based parameters for rendering diagnoses and a series of studies assessing concordance of virtual slide and light microscopy diagnoses. This article documents the empirical foundations of telepathology. A selective review of the research literature during the past decade (2005-2016) was conducted using robust research design and adequate sample size as criteria for inclusion. The evidence regarding feasibility/acceptance of telepathology and related information technology applications has been well documented for several decades. The majority of evidentiary studies focused on intermediate outcomes, as indicated by comparability between telepathology and conventional light microscopy. A consistent trend of concordance between the two modalities was observed in terms of diagnostic accuracy and reliability. Additional benefits include use of telepathology and whole slide imaging for teaching, research, and outreach to resource-limited countries. Challenges still exist, however, in terms of use of telepathology as an effective diagnostic modality in clinical practice.

Field evaluation of a PfHRP-2/pLDH rapid diagnostic test and light microscopy for diagnosis and screening of falciparum malaria during the peak seasonal transmission in an endemic area in Yemen.

BackgroundMalaria is a public health threat in Yemen, with 149,451 cases being reported in 2013. Of these, Plasmodium falciparum represents 99 %. Prompt diagnosis by light microscopy (LM) and rapid diagnostic tests (RTDs) is a key element in the national strategy of malaria control. The heterogeneous epidemiology of malaria in the country necessitates the field evaluation of the current diagnostic strategies, especially RDTs. Thus, the present study aimed to evaluate LM and an RDT, combining both P. falciparum histidine-rich protein-2 (PfHRP-2) and Plasmodium lactate dehydrogenase (pLDH), for falciparum malaria diagnosis and survey in a malaria-endemic area during the transmission season against nested polymerase chain reaction (PCR) as the reference method.MethodsA household-based, cross-sectional malaria survey was conducted in Mawza District, a malaria-endemic area in Taiz governorate. A total of 488 participants were screened using LM and PfHRP-2/pLDH RDT. Positive samples (160) and randomly selected negative samples (52) by both RDT and LM were further analysed using 18S rRNA-based nested PCR.ResultsThe sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) of the RDT were 96.0 % (95 % confidence interval (CI): 90.9–98.3), 56.0 % (95 % CI: 44.7–66.8), 76.3 % (95 % CI: 69.0–82.3), and 90.4 % (95 % CI: 78.8–96.8), respectively. On the other hand, LM showed sensitivity of 37.6 % (95 % CI: 29.6–46.3), specificity of 97.6 % (95 % CI: 91.7–99.7), PPV of 95.9 % (95 % CI: 86.3–98.9), and NPV of 51.3 % (95 % CI: 43.2–59.2). The sensitivity of LM dropped to 8.5 % for detecting asymptomatic malaria. Malaria prevalence was 32.8 % (32.1 and 37.5 % for ≥10 and <10 years, respectively) with the RDT compared with 10.7 % (10.8 and 9.4 % for age groups of ≥10 and <10 years, respectively) with LM. Among asymptomatic malaria individuals, LM and RDT-based prevalence rates were 1.6 and 25.6 %, respectively. However, rates of 88.2 and 94.1 % of infection with P. falciparum were found among patients who reported fever in the 48 h prior to the survey by LM and PfHRP-2/pLDH RDT, respectively.ConclusionsThe PfHRP-2/pLDH RDT shows high sensitivity for the survey of falciparum malaria even for asymptomatic malaria cases. Although the RDT had high sensitivity, its high false-positivity rate limits its utility as a single diagnostic tool for clinical diagnosis of malaria. On the other hand, low sensitivity of LM indicates that a high proportion of malaria cases is missed, underestimating the true prevalence of malaria in the community. Higher NPV of PfHRP-2/pLDH RDT than LM can give a straightforward exclusion of malaria among febrile patients, helping to avoid unnecessary presumptive treatments.

Sixty-five thousand shades of gray: importance of color in surgical pathology diagnoses

Digital whole slide imaging (WSI) is a diagnostic modality that has gained acceptance as a tool for use in some areas of surgical pathology such as remote consultations. Accurate control of color representation of digitally rendered images of histologic sections is considered an important parameter of WSI. Currently, professional societies, physicians, and other stakeholders are in the process of establishing clinical guidelines outlining the use of these devices, which include color integrity and color calibration of scanners and viewing devices. Although color is a component of surgical pathology diagnoses, it was posited that pathologists could accurately diagnose surgical specimens without color. To test this hypothesis, 5 pathologists were presented breast biopsy specimens from 20 patients consisting of 22 separate tissue specimens and WSI of 158 hematoxylin and eosin-stained slides imaged at ×20. No special stains were included. The pathologists reviewed each case using a 16-bit grayscale monitor and rendered a diagnosis for each case. Diagnoses were compared to the original light microscopy diagnoses and scored for concordance. A 92.7% concordance was observed. Discordant diagnoses represented well-known areas of diagnostic disagreement in breast pathology as well as known limitations of WSI. The research demonstrated that surgical pathologists did not rely primarily on color to render accurate diagnoses of breast biopsy cases but rather used architectural features of tissue and cellular morphology to reach a diagnostic conclusion. This research did not suggest that color is an unimportant factor in pathology diagnosis, but its importance may be overstated.

Comparison of detection methods to estimate asexual Plasmodium falciparum parasite prevalence and gametocyte carriage in a community survey in Tanzania

BackgroundThe use of molecular techniques to detect malaria parasites has been advocated to improve the accuracy of parasite prevalence estimates, especially in moderate to low endemic settings. Molecular work is time-consuming and costly, thus the effective gains of this technique need to be carefully evaluated. Light microscopy (LM) and rapid diagnostic tests (RDT) are commonly used to detect malaria infection in resource constrained areas, but their limited sensitivity results in underestimation of the proportion of people infected with Plasmodium falciparum. This study aimed to evaluate the extent of missed infections via a community survey in Tanzania, using polymerase chain reaction (PCR) to detect P. falciparum parasites and gametocytes.MethodsThree hundred and thirty individuals of all ages from the Kilombero and Ulanga districts (Tanzania) were enrolled in a cross-sectional survey. Finger prick blood samples were collected for parasite detection by RDT, LM and molecular diagnosis using quantitative 18S rRNA PCR and msp2 nPCR. Gametocytes were detected by LM and by amplifying transcripts of the gametocyte-specific marker pfs25.ResultsResults from all three diagnostic methods were available for a subset of 226 individuals. Prevalence of P. falciparum was 38% (86/226; 95% CI 31.9–44.4%) by qPCR, 15.9% (36/226; 95% CI 11.1–20.7%) by RDT and 5.8% (13/226; 95% CI 2.69- 8.81%) by LM. qPCR was positive for 72% (26/36) of the RDT-positive samples. Gametocyte prevalence was 10.6% (24/226) by pfs25-qRT-PCR and 1.2% by LM.ConclusionsLM showed the poorest performance, detecting only 15% of P. falciparum parasite carriers identified by PCR. Thus, LM is not a sufficiently accurate technique from which to inform policies and malaria control or elimination efforts. The diagnostic performance of RDT was superior to that of LM. However, it is also insufficient when precise prevalence data are needed for monitoring intervention success or for determining point prevalence rates in countrywide surveillance. Detection of gametocytes by PCR was 10-times more sensitive than by LM. These findings support the need for molecular techniques to accurately estimate the human infectious reservoir and hence the transmission potential in a population.

Concordance between digital pathology and light microscopy in general surgical pathology: a pilot study of 100 cases

Aim(1) A pilot study to determine the accuracy of interpretation of whole slide digital images in a broad range of general histopathology cases of graded complexity. (2) To survey the...

G.P.77: The Lymphoid Follicle Variant of juvenile dermatomyositis

Juvenile dermatomyositis (jDM) is an inflammatory disease that affects small vessels of the muscle, the skin, and other organs, which may lead to severe systemic disease. Muscle biopsy can help to secure a firm diagnosis and thus serve as an important adjunct to atypical clinical presentation. As previously suggested, ectopic lymphoid follicle-like structures (LFLS) in inflamed muscle could indicate a severe course of disease. Histological evaluation of frozen muscle samples was employed to visualize the cellular organisation of ectopic lymphoid structures in muscle biopsies obtained from 2 patients diagnosed with juvenile dermatomyositis (jDM). Clinical presentation, morphological features, as well as treatment and follow-up were assessed and documented. Electron microscopy was used to confirm the light microscopic diagnosis of jDM. Clonality analysis of B-cell populations using polymerase chain reaction (PCR) was performed. Muscle biopsy of both patients fulfilled the morphological ENMC criteria of DM. Analyses of muscle biopsy samples revealed LFLS that showed a remarkable similarity to secondary lymphoid organs (SLOs) with distinct T- and B-cell compartmentalization. In contrast to previous reports our two patients exhibited a mild clinical presentation and responded favourably to therapy. Together, our data suggest that the clinical spectrum of jDM appears to be more diverse than so far documented, and that the presence of SLOs is not inevitably linked to unfavourable prognosis.

The lymphoid follicle variant of dermatomyositis.

Objective:To investigate the clinical and morphologic spectrum of early adult–onset dermatomyositis (DM), an inflammatory disease that affects small vessels of the muscle and the skin.Methods:Histologic evaluation of frozen muscle samples was employed to visualize the cellular organization of ectopic lymphoid structures in muscle biopsies obtained from 2 patients diagnosed with DM. Clinical presentation and morphologic features, as well as treatment and follow-up, were assessed and documented. Electron microscopy was used to confirm the light microscopic diagnosis of DM. Clonality analysis of B-cell populations using PCR was performed.Results:Muscle biopsy of both patients fulfilled the morphologic European Neuromuscular Centre criteria of DM. Analyses of muscle biopsy samples revealed ectopic lymphoid follicle-like structures that showed a remarkable similarity to secondary lymphoid organs (SLOs) with distinct T- and B-cell compartmentalization. Our 2 patients exhibited an atypical and mild clinical presentation and responded favorably to therapy.Conclusions:The clinical and histopathologic features of DM can be atypical, and the presence of SLOs is not inevitably linked to an unfavorable prognosis.

A quality improvement assessment of multiple, concurrent flow cytometry analyses at a tertiary care center.

The utility of flow cytometry (FC) in diagnosis and staging of hematologic malignancy is controversial. Often, multiple specimens from the same patient are processed concurrently for FC analyses, alongside tissue for histomorphologic diagnosis. To assess the diagnostic utility of multiple, concurrent FC analyses, a 10-year retrospective review of cases with ≥2 concurrent specimens (from the same patient) submitted for FC was conducted. Light microscopic (LM) diagnoses were compared to FC findings, and the contribution of FC results to final diagnoses was examined. Of 4058 specimens (predominantly lymph nodes, bone marrows, and oropharyngeal tissues) submitted for FC analyses, 129 (3.2%) represented cases with multiple (average: 2.19) concurrent FC analyses. All were accompanied by tissues and/or aspirates for LM examination. In 115 (89.1%) cases, multiple FC analyses were performed prior to morphologic examination. In 87.0% of those cases, ≥1 FC result(s) aligned with LM findings. In 15 (13.0%) cases where FC results differed from morphologic diagnoses, 86.7% (13/15) failed to detect an abnormal cell population by FC in the presence of a hematologic malignancy by LM. In one case (0.9%), FC detected a lymphoma, without morphologic evidence by LM. Overall, multipart FC failed to demonstrate a significant contribution in initial diagnoses of hematologic malignancies compared with analysis of a single specimen.