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Pharmacokinetics of paracetamol in adults after cardiac surgery.

The pharmacokinetics of paracetamol in adults after cardiac surgery have not been described. Twenty patients were randomized to receive either paracetamol 2 g through a nasogastric tube and as a suppository eight hours later or vice versa. Arterial blood samples were taken at 0.5, one, two, four, six and eight hours after dosing. Each patient was studied for 16 h. There were 16 males and three females. One patient was excluded because of sampling errors. The mean age was 59 (SD 8) years and the mean weight 84 kg (16). The time-concentration profiles for each individual were used to estimate pharmacokinetic parameters using a non-linear mixed effects model (NONMEM). Population parameter estimates with coefficient of variation (CV%), standardized to a 70 kg person, for a one-compartment model with first order input, lag time and first order elimination were volume of distribution 127l (28) and clearance 26.4 l/h (29) Rectal paracetamol had an absorption half-life (Tabs) of 2.02 h (31) with a lag time of 0.28 h. The absorption half-life for the oral preparation was 1.49 h (81) with a lag time of 0.17 h. The relative bioavailability of the rectal compared to the oral formulation was 0.98 (18). Concentrations after either nasogastric or rectal paracetamol 2 g were below a target concentration of 10 mg/l, which is associated with analgesia. Absorption after nasogastric administration was slow compared to healthy adults (Tabs 0.06 to 0.7 h) and the bioavailability was half that expected, due to nasogastric loss. Parameter estimates had large variability. Paracetamol is unlikely to have useful clinical impact in the majority of patients when standard doses (6 g/day) are given on day 1 after cardiac surgery.

Acetaminophen↗

Adequacy of routine EEG examinations in neonates with clinically suspected seizures.

This study identified the clinical and electroencephalographic (EEG) characteristics that distinguished neonates with EEG-confirmed seizures from those without, in order to assess the adequacy of routine short-term EEG examinations in neonates with clinically suspected seizures. Two different subgroups of tracings were analyzed: EEGs performed on therapeutically paralyzed (TP+) neonates and EEGs performed on non-therapeutically paralyzed (TP-) neonates. The rate of electrographic seizures, abnormal EEG background activity, and excessive sharp EEG transients (SETs) was significantly more common in the tracings performed on TP- neonates. In lethargic/comatose TP- neonates with clinically suspected seizures and abnormal EEG background activity, the rate of EEGs with excessive SETs (implying a "lowered seizure threshold") occurred equally in tracings with or without documented electrographic seizures. Consequently, we suspect that routine EEGs may be inadequate to electrographically confirm suspected seizures in some TP- neonates due to a large sampling error. In contrast, routine 40-minute EEGs are probably adequate to seek evidence of electrographic seizure activity in TP+ neonates because their seizure rate is low and most do not display background abnormalities or excessive SETs.

Cerebral Cortex↗

Outdoor NOx and stroke mortality: adjusting for small area level smoking prevalence using a Bayesian approach.

There is increasing evidence, mainly from daily time series studies, linking air pollution and stroke. Small area level geographical correlation studies offer another means of examining the air pollution-stroke association. Populations within small areas may be more homogeneous than those within larger areal units, and census-based socioeconomic information may be available to adjust for confounding effects. Data on smoking from health surveys may be incorporated in spatial analyses to adjust for potential confounding effects but may be sparse at the small area level. Smoothing, using data from neighbouring areas, may be used to increase the precision of smoking prevalence estimates for small areas. We examined the effect of modelled outdoor NOx levels on stroke mortality using a Bayesian hierarchical spatial model to incorporate random effects, in order to allow for unmeasured confounders and to acknowledge sampling error in the estimation of smoking prevalence. We observed an association between NOx and stroke mortality after taking into account random effects at the small area level. We found no association between smoking prevalence and stroke mortality at the small area level after modelling took into account imprecision in estimating smoking prevalence. The approach we used to incorporate smoking as a covariate in a single large model is conceptually sound, though it made little difference to the substantive results.

Age Factors↗

Diagnostic Pitfalls in Surgical Pathology- Uncovered by a Review of Malpractice Claims: Part II. Breast Fine Needle Aspirations.

Breast fine needle aspiration (FNA) biopsy accounted for 6% of surgical pathology and FNA claims reviewed from 1995-97. The majority of these claims were for false negative breast FNA resulting from sampling error in a woman with a palpable breast mass. Controversies concerning the definition of specimen adequacy for breast FNA are discussed and a strategy for minimizing the management and liability consequences of the problem is proposed. Claims for false positive breast FNA usually result from interpretive error. Int J Surg Pathol 8(3):229-231, 2000

Journal Article↗

Optical detection and eradication of dysplastic Barrett's esophagus.

Dysplastic Barrett's esophagus is a condition that offers multiple diagnostic and therapeutic challenges. The diagnosis of dysplasia within Barrett's esophagus currently relies on periodic endoscopic surveillance with multiple biopsies, a methodology limited by random sampling error, inconsistent histopathologic interpretation and delay in diagnosis. Optical spectroscopic and imaging techniques have the potential to identify dysplastic or early neoplastic lesions in real-time. These diagnostic modalities are needed to enhance the endoscopic surveillance of Barrett's esophagus in the future as well as help to define lesions for endoscopic therapy. Esophagectomy has been the standard of care for Barrett's esophagus with high-grade dysplasia although it is a procedure associated with significant morbidity and mortality. Minimally invasive endoscopic ablative therapies are attractive and less morbid alternatives to esophagectomy, with promising results obtained from the use of light-activated drugs (i.e., photodynamic therapy). The combination of novel optical diagnostic techniques and therapies will provide the endoscopist with much needed tools that can considerably enhance the management of patients with Barrett's esophagus. This article reviews the current status and future prospects of optical-based modalities for diagnosis and therapy of dysplastic Barrett's esophagus.

Algorithms↗

Estimation of collagen content of liver specimens. Variation among animals and among hepatic lobes in cirrhotic rats.

We undertook a study to evaluate the correlation between morphometric evaluation and colorimetric determination of hepatic collagen content, and to analyze the variation among animals as well as among lobes of the same liver in hepatic collagen content after CCl4-induced micronodular cirrhosis. The results revealed a significant correlation (r = 0.9458; p less than 0.001) between the morphometric and colorimetric methods of collagen evaluation of liver specimens; both methods also significantly distinguished data obtained from controls and from cirrhotic rats (p less than 0.0005). After induction of micronodular cirrhosis by chronic CCl4 administration, a highly significant variation in hepatic collagen content was observed among animals (p less than 0.0001). By contrast, no significant difference in collagen content was observed (p less than 0.05) among hepatic lobes of a given animal. These results indicate that in this animal model of liver cirrhosis, interpretation of biochemical data would benefit by being related to the severity of the hepatic collagen infiltration of each animal. Our data also show that representative values for total hepatic collagen infiltration can be obtained from a single liver specimen; we suggest, however, that the specimen be taken from a major lobe of the liver and that a sufficiently large number of animals be used to avoid occasional sampling errors.

Animals↗

Bayesian model accounting for within-class biological variability in Serial Analysis of Gene Expression (SAGE).

BACKGROUND: An important challenge for transcript counting methods such as Serial Analysis of Gene Expression (SAGE), "Digital Northern" or Massively Parallel Signature Sequencing (MPSS), is to carry out statistical analyses that account for the within-class variability, i.e., variability due to the intrinsic biological differences among sampled individuals of the same class, and not only variability due to technical sampling error. RESULTS: We introduce a Bayesian model that accounts for the within-class variability by means of mixture distribution. We show that the previously available approaches of aggregation in pools ("pseudo-libraries") and the Beta-Binomial model, are particular cases of the mixture model. We illustrate our method with a brain tumor vs. normal comparison using SAGE data from public databases. We show examples of tags regarded as differentially expressed with high significance if the within-class variability is ignored, but clearly not so significant if one accounts for it. CONCLUSION: Using available information about biological replicates, one can transform a list of candidate transcripts showing differential expression to a more reliable one. Our method is freely available, under GPL/GNU copyleft, through a user friendly web-based on-line tool or as R language scripts at supplemental web-site.

Astrocytoma↗

Managerial attitude to the implementation of quality management systems in Lithuanian support treatment and nursing hospitals.

BACKGROUND: The regulations of the Quality Management System (QMS) implementation in health care organizations were approved by the Lithuanian Ministry of Health in 1998. Following the above regulations, general managers of health care organizations had to initiate the QMS implementation in hospitals. As no research on the QMS implementation has been carried out in Lithuanian support treatment and nursing hospitals since, the objective of this study is to assess its current stage from a managerial perspective. METHODS: A questionnaire survey of general managers of Lithuanian support treatment and nursing hospitals was carried out in the period of January through March 2005. Majority of the items included in the questionnaire were measured on a seven-point Likert scale. During the survey, a total of 72 questionnaires was distributed, out of which 58 filled-in ones were returned (response rate 80.6 per cent; standard sampling error 0.029 at 95 per cent level of confidence). RESULTS: Quality Management Systems were found operating in 39.7 per cent of support treatment and nursing hospitals and currently under implementation in 46.6 per cent of hospitals (13.7% still do not have it). The mean of the respondents' perceived QMS significance is 5.8 (on a seven-point scale). The most critical issues related to the QMS implementation include procedure development (5.5), lack of financial resources (5.4) and information (5.1), and development of work guidelines (4.6), while improved responsibility and power sharing (5.2), better service quality (5.1) and higher patient satisfaction (5.1) were perceived by the respondents as the key QMS benefits. The level of satisfaction with the QMS among the management of the surveyed hospitals is mediocre (3.6). However it was found to be higher among respondents who were more competent in quality management, were familiar with ISO 9000 standards, and had higher numbers of employees trained in quality management. CONCLUSION: QMSs are perceived to be successfully running in one third of the Lithuanian support treatment and nursing hospitals. Its current implementation stage is dependent on the hospital size - the bigger the hospital the more success it meets in the QMS implementation. As to critical Quality Management (QM) issues, hospitals tend to encounter such major problems as lack of financial resources, information and training, as well as difficulties in procedure development. On the other hand, the key factors that assist to the success of the QMS implementation comprise managerial awareness of the QMS significance and the existence of employee training systems and audit groups in hospitals.

Attitude of Health Personnel↗

Comparative assessment of Yale Single Question and Beck Depression Inventory Scale in screening for depression in multiple sclerosis.

OBJECTIVES: To examine if depression in multiple sclerosis (MS) can be accurately recognized using the Yale Single Question (YSQ) screen as compared with the Beck Depression Inventory (BDI), a 21-item self-report rating scale for depression. In addition, we sought to assess the sensitivity, specificity the positive predictive value (PPV) and the negative predictive value (NPV) of the YSQ. BACKGROUND: Depression associated with MS is a major contributor to morbidity. Screening for depression in patients with MS currently includes the BDI, which measures characteristic attitudes and symptoms of depression. However, in a busy outpatient clinic, the BDI might not be the most appropriate instrument, particularly if depression screening can be assessed accurately using simpler techniques that are easy to administer and consume less time. We compared the accuracy of the YSQ screen response against the BDI to screen for depression in MS patients, in an outpatient setting. METHODS: This is a comparative outcome study of two 'instruments' used for screening depression in MS patients in an academic outpatient setting. All patients were initially screened for depression by asking patients the YSQ--'Do you frequently feel sad or depressed?', followed by BDI administration. Depression was defined as a score of > or = 13 on the BDI. One hundred and twenty successive patients who presented to the MS clinic at Washington University School of Medicine and met the criteria for diagnosis of MS were screened for depression. All patients diagnosed as having MS, regardless of type, were included in the study. RESULTS: Of the 120 patients studied, a total of 49 of 120 were clinically depressed as defined by a BDI cut-off of > or = 13; 71 of 120 were not. The sensitivity of the YSQ was 32 of 49 = 65.3% with a 95% confidence interval (0.50, 0.78), specificity was 62 of 71 = 87.3% (0.77, 0.94), PPV was 32 of 41 = 78.0% (0.62, 0.89) and NPV was 62 of 79 = 78.5% (0.68, 0.87). Of the 49 patients depressed by BDI criteria, 17 responded 'no' to the YSQ, yielding a false-negative rate of 34.7% (0.22, 0.50). The Wilcoxon-Mann-Whitney test for difference in age among those on antidepressants compared with those who were not showed no statistical difference (P = 0.35). For patients on antidepressants, the mean BDI score was 16.0+/-8.9 (mean+/-SD) and 9.5+/-8.7 for those not on antidepressants. Differences in BDI scores among patients on antidepressants versus those who were not were statistically significant (P < 0.0001). Patients on antidepressants had significantly higher BDI scores. CONCLUSIONS: Our results show that the YSQ cannot replace the BDI as a screening instrument for depression in MS. The YSQ could not identify 34.7% of patients who were depressed by BDI criteria. However, as reported in a published study, BDI missed 30% of cases with early depression in MS when a cut-off of > or = 13 was used. The YSQ appears to be specific in ruling out depression when a patient is not depressed. MS is a chronic disease and since prevalence of depression varies, it is important to screen patients repeatedly over time so as not to miss the diagnosis. That BDI scores were higher among those taking antidepressants underscores the fact that this subset of patients need to be on medication, but the higher scores could also represent a sampling error since the duration of antidepressant use was not studied.

Adult↗

Measurement and mapping of liver iron concentrations using magnetic resonance imaging.

Measurement of liver iron concentration (LIC) is an important clinical procedure in the management of transfusional iron overload with iron chelation. LIC gives an indication of over- or underchelation. Although chemical assay of needle biopsy samples from the liver has been considered the "gold standard" of LIC measurement, needle biopsy sampling errors can be surprisingly large owing to the natural spatial variation of LIC throughout the liver and the small size of biopsy specimens. A magnetic resonance imaging technique has now been developed that enables safe noninvasive measurement and imaging of LIC with a known accuracy and precision. Measurements of LIC can be made over the range of LIC encountered in clinical practice. The technique is based on the measurement and imaging of proton transverse relaxation rates (R2) within the liver. The R2 imaging technique can be implemented on most clinical 1.5-T MRI instruments, making it readily available to the clinical community.

Biomarkers↗

Residual abdominal masses in aggressive non-Hodgkin's lymphoma after combination chemotherapy: significance and management.

When patients with aggressive lymphoma present with intraabdominal disease, a stable residual mass is frequently detected radiographically at the time of the clinical complete remission. To discern the optimal management for this clinical problem, we reviewed 241 patients with aggressive lymphoma treated at the National Cancer Institute (NCI) from 1977 to 1986. Seventy-two/241 patients (30%) had an abdominal mass at diagnosis and 29/72 (40%) were left with a radiographically detectable residual mass at clinical complete remission. The likelihood of a residual mass was much higher for patients with bulky disease (P2 less than .0003) (two-tailed test [P2]). Twenty-nine patients had radiologically stable residual masses after therapy, and of 22 (76%) with pathologic evaluations, 21 had negative specimens (95%) and one was positive (5%). None of the patients with negative pathologic evaluation has relapsed in the abdominal site (median follow-up, 31 months). Seven patients were observed clinically without laparotomy: five are alive, without evidence of disease, at 2 to 9 years; two relapsed with disseminated disease within 2 months of chemotherapy. Initial tumor size and size of the residual mass did not correlate with residual disease, since residual masses identified by radiographic examination did not usually harbor viable lymphoma cells. Aspiration cytology was negative for residual tumor in 15/16 cases. One negative result was not confirmed at laparotomy, presumably due to sampling error. The one positive aspiration was followed by a negative laparotomy, possibly due to subsequent tumor necrosis. Restaging laparotomy has a low yield. In most patients with aggressive lymphoma who have otherwise completely responded to carefully administered full-dose combination chemotherapy, stable residual abdominal masses can be closely followed clinically without surgical exploration.

Antineoplastic Combined Chemotherapy Protocols↗

The convergent validity of MMPI and Rorschach scales: an extension using profile scores to define response and character styles on both methods and a reexamination of simple Rorschach response frequency.

Past research indicated the convergence of Rorschach and MMPI scales may be a function of (a) simple Rorschach response frequency (R) or (b) complex response-character styles on both methods. In this study, new criteria were developed for defining the second assumption using F and K from the MMPI and R and Lambda from the Rorschach. Although substantially different from the factor criteria used previously (KS = .45 and .30), the new criteria still produced the expected pattern of correlations among MMPI and Rorschach scales. Averaged across 17 constructs, the new criteria produced strong validity coefficients for patients with similar styles (M composite r = .50), though they were less effective for patients with discordant styles (M composite r = -.27). It was also demonstrated that R by itself does not moderate convergent validity. Rather, statistical modeling with two sets of 300 random samples (a) demonstrated the prior findings related to R were the result of sampling error and (b) supported the general hypothesis that Rorschach and MMPI scales correlate to the extent response-character styles correlate. Implications are considered.

Adolescent↗

Small group learning in medical education: a second look at the Springer, Stanne, and Donovan meta-analysis.

All in all, the evidence is not convincing. Only four of the nine randomized studies used the conventional small-group learning paradigm and qualify as studies of small-group learning, which are relevant to medical education. The results of one of the four are impossible to interpret because of the involvement of the investigator in teaching and test construction. The three remaining studies showed no effect, a negative effect, and a positive effect, respectively. The nonrandomized studies failed to establish the comparability of the groups. The evidence does not support the authors' call for "more widespread implementation of small-group learning in undergraduate SMET". Small-group learning has not been shown to support the acquisition of content any better [or worse] than large-group learning. In medical education, small-groups are employed in large part to develop team work skills, communication skills, and peer- and self-assessment skills. But these outcomes are not addressed in this meta-analysis. More seriously, our rereading of these studies raises general concerns about meta-analysis in education, which have important implications for evidence-based medical education. The meta-analysis under discussion at first appeared to be just the kind needed to guide an evidence-based educational enterprise. However, a closer look revealed both what is lacking in the meta-analysis and some of the ways educational research and reporting need to be changed if anything like evidence-based education is ever to become a reality. At the least, study design must be clearly described. In addition, if the design is nonrandomized, the groups should be described in sufficient detail to allow a meaningful interpretation of the role of preexisting differences on the outcome measures. (This is why we limited our discussion here to the randomized studies.) Also, effect-size measures should be reported for all comparisons that bear on the impact of the intervention, including preexisting differences. Reporting significance is not enough. This shows only whether sampling error can be ruled out (with a low probability of error, p < .05) as a possible explanation of the connection between the intervention and the outcome. The effect can still be trivial and the comparisons confounded. In addition, descriptions of the actual educational interventions employed need to be more comprehensive and precise. For the most part, the papers would have been strengthened by providing more information for replicating the studies and for deciding which should be included in a given meta-analysis. Perhaps most seriously, our rereading of these studies makes us wonder about the possibility of meaningfully synthesizing the results of educational studies, given their idiosyncrasies and their many extraneous, uncontrolled factors. The conclusions from most educational studies, then--whether randomized or not--must be highly qualified, with explicit warnings about preexisting differences and other confounding factors that plausibly account for the study results. However, these narrative qualifications do nothing to adjust the effect-size measures, which are typically pooled or synthesized across studies--confounds and all. The idiosyncrasies of the studies seem to preclude a blanket qualification that can be applied conceptually across the collection of studies to arrive at a sound conclusion from the synthesis. In brief, the meta-analysis considered here does not support the application of small-group learning in medical education and it raises questions about meta-analysis in education with implications for evidence-based education.

Curriculum↗

Lack of preferential transmission of diabetic HLA alleles by healthy parents to offspring in Spanish diabetic families.

HLA-DR3 or -DR4 segregation distortion to normal or insulin-dependent (ID) diabetic offspring of 108 Spanish families whose parents were healthy was not observed; however, DR3 or DR4 ID offspring is significantly increased in the present study, since parents were chosen after tracing ID children. These results are discrepant with those found by others in families with diabetic parents in other ethnic groups. These conflicting data could be due to sampling errors or segregation distortion. Thus, ethnic group differences in a genetic (T/t-like) or metabolic mechanism might confer advantages to DR3- or DR4-bearing gametes from ID diabetic parents, but segregation distortion might only affect certain HLA DR3 or DR4 extended haplotypes which are frequent and characteristic for certain ethnic groups (i.e. B8-DR3-BfS-C4AQOB1 and Bw62-DR3-BfS-C4A383 in most caucasians) but not for other haplotypes in other ethnic groups (Spaniards; B18-DR3-BfF1-C4A3BQO and BwX-DR4-BfX-C4AXBX).

Adolescent↗

Perfusion magnetic resonance imaging predicts patient outcome as an adjunct to histopathology: a second reference standard in the surgical and nonsurgical treatment of low-grade gliomas.

OBJECTIVE: To determine whether relative cerebral blood volume (rCBV) can predict patient outcome, specifically tumor progression, in low-grade gliomas (LGGs) and thus provide a second reference standard in the surgical and postsurgical management of LGGs. METHODS: Thirty-five patients with histologically diagnosed LGGs (21 low-grade astrocytomas and 14 low-grade oligodendrogliomas and low-grade mixed oligoastrocytomas) were studied with dynamic susceptibility contrast-enhanced perfusion magnetic resonance imaging. Wilcoxon tests were used to compare patients in different response categories (complete response, stable, progressive, death) with respect to baseline rCBV. Log-rank tests were used to evaluate the association of rCBV with survival and time to progression. Kaplan-Meier time-to-progression curves were generated. Tumor volumes and CBV measurements were obtained at the initial examination and again at follow-up to determine the association of rCBV with tumor volume progression. RESULTS: Wilcoxon tests showed patients manifesting an adverse event (either death or progression) had significantly higher rCBV (P = 0.003) than did patients without adverse events (complete response or stable disease). Log-rank tests showed that rCBV exhibited a significant negative association with disease-free survival (P = 0.0015), such that low rCBV values were associated with longer time to progression. Kaplan-Meier curves demonstrated that lesions with rCBV less than 1.75 (n = 16) had a median time to progression of 4620 +/- 433 days, and lesions with rCBV more than 1.75 (n = 19) had a median time to progression of 245 +/- 62 days (P < 0.005). Lesions with low baseline rCBV (< 1.75) demonstrated stable tumor volumes when followed up over time, and lesions with high baseline rCBV (> 1.75) demonstrated progressively increasing tumor volumes over time. CONCLUSION: Dynamic susceptibility contrast-enhanced perfusion magnetic resonance imaging may be used to identify LGGs that are either high-grade gliomas, misdiagnosed because of sampling error at pathological examination or that have undergone angiogenesis in the progression toward malignant transformation. This suggests that rCBV measurements may be used as a second reference standard to determine the surgical management/risk-benefit equation and postsurgical adjuvant therapy for LGGs.

Adolescent↗

Accuracy of 11-gauge vacuum-assisted core biopsy of mammographic breast lesions.

BACKGROUND: Image-guided percutaneous biopsy has largely replaced excisional biopsy of mammographic lesions. Vacuum-assisted core biopsy has improved sampling of such lesions. The objectives of this study were to define the accuracy of the vacuum-assisted 11-gauge stereotactic core biopsy in sampling of atypical ductal hyperplasia (ADH) and ductal carcinoma in situ (DCIS) and to define histologic and mammographic features of target lesions, which predict sampling errors. METHODS: Between October 1996 and March 2000, 1341 patients underwent stereotactic 11-gauge vacuum-assisted biopsy. Patients with ADH or DCIS were encouraged to undergo excisional biopsy. RESULTS: Surgical excision of 37 ADH lesions revealed 5 missed DCIS lesions and 1 missed invasive cancer. Twelve of 91 DCIS lesions were upstaged to invasive cancer upon excision. The underestimation rate was highest in patients with DCIS when the target lesion for biopsy was a zone of calcifications >1.5 cm. No correlation existed between the histologic features of DCIS lesions diagnosed by stereotactic biopsy and the presence of infiltrating disease on excision. CONCLUSIONS: Vacuum-assisted 11-gauge stereotactic core biopsy understages 13.2% and 13.5% of DCIS and ADH lesions, respectively. In patients with DCIS found by stereotactic biopsy, a target zone of calcifications >1.5 cm is associated with a higher underestimation rate of infiltrating disease.

Biopsy, Needle↗

A pilot study of a combined dermoscopic-pathological approach to the telediagnosis of melanocytic skin neoplasms.

We examined a combined (dermoscopic-pathological) approach to the telediagnosis of melanocytic skin lesions. A store-and-forward teleconsultation was simulated. Dermoscopic and histopathology images from 12 melanocytic lesions were stored in a telepathology workstation. A dermoscopy consultant, a histopathology consultant and an expert in dermoscopic-pathological correlation gave their diagnoses and comments on the images. The consensus diagnosis between two teleconsultants on the original histological slides was regarded as the gold standard. The diagnostic accuracy was 83% (including one false negative diagnosis of malignancy) for teledermoscopy and 100% for teledermatopathology. The combined approach detected one case that showed a much greater atypia on dermoscopy than on histopathology. In this case step-sections of the sample were deemed to be required for definite diagnosis. The combined approach was helpful in detecting macroscopic and microscope sampling errors of melanocytic lesions during teleconsultation.

Adolescent↗

Four years experience with teleneuropathology.

Between 2002 and 2005, we made 343 intraoperative frozen section diagnoses with a telepathology system, which connected a neurosurgical department to our department of pathology. An expert neuropathologist performed at least one brief gross examination, and this was followed by a smear preparation and a frozen section slide for each case. Frozen section diagnosis lasted on average 26.1 min, calculated from the beginning of gross examination until the surgeon was given the diagnosis. The majority of cases (283 or 83%) were diagnosed in 15-40 min. The mean time needed for macroscopic examination was 3.0 min, time for staining 4.2 min, smear diagnosis took 5.4 min and time for histological diagnosis 10.7 min. Telemicroscopy of a smear slide took 11 times longer compared with light microscopy, and telemicroscopy of a frozen section slide took 16 times longer than with light microscopy. In 6% of cases, the telepathology software posed technical problems, which delayed the time of diagnosis, but not by more than 4 min. We were able to render a diagnosis in all cases (system reliability 100%). After eliminating sampling errors (i.e. cases with no diagnostic material in the frozen section slides and/or in smear preparations), the diagnostic accuracy for telepathology was 97.9%.

Frozen Sections↗