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PubMed2006

Intraoperative assessment of ovarian tumors: a 5-year review with assessment of discrepant diagnostic cases.

Frozen section is often requested in the intraoperative assessment of patients, presenting with ovarian masses, to provide guidance for appropriate surgical management. To assess the accuracy of frozen section and identify causes of diagnostic error, we reviewed 914 consecutive ovarian frozen sections performed over a 5-year period in 2 laboratories; one of which provides a general surgical pathology service and, the other, a specialist gynecologic pathology service. Cases, in which there were significant diagnostic discrepancies between the intraoperative and the final histological diagnoses, were reviewed. The series included 552 benign lesions (60.4%), 96 borderline (atypical proliferating) epithelial tumors (10.5%), and 266 malignancies (29.1%). The overall accuracy of frozen section diagnosis was 95.3%. There were 43 cases with diagnostic discrepancy; 20 (3.8% cases) of which were reported in the specialist laboratory and 23 (5.9% cases) in the general laboratory. Underdiagnosis of tumor type accounted for 32 of 43 discrepant cases and was most frequent in borderline mucinous tumors. The most common cause of overdiagnosis was the misinterpretation of serous cystadenofibroma as borderline serous tumor. Slide review of the 41 assessable cases indicated that sampling error, pathologist misinterpretation, and suboptimal slide preparations contributed to misdiagnoses in 17, 23, and 9 tumors, respectively (in 9 cases, 2 factors were contributory), whereas no specific error was identified in the remaining case. Technical factors and pathologist misinterpretation were more common in the general pathology laboratory. This study confirms that ovarian frozen section is a generally reliable technique, but there are problematic areas, particularly involving the assessment of borderline tumors.

Cystadenoma, Mucinous↗
PubMed2002

Intestinal metaplasia of the gastric cardia: A prospective study with enhanced magnification endoscopy.

OBJECTIVE: There are no endoscopic features that distinguish intestinal metaplasia of the cardia (CIM) from the normal cardia. Biopsy specimens are therefore randomly obtained from normal-appearing mucosa with significant potential sampling errors. Enhanced magnification endoscopy involves the combined use of magnification endoscopy with acetic acid instillation. This study assessed the value of enhanced magnification endoscopy in detecting CIM. METHODS: Patients undergoing elective upper endoscopy were invited to participate in the study. Patients were included if the squamocolumnar junction and the esophagogastric junction were judged to be at the same level. Enhanced magnification endoscopy was performed with 3% acetic acid instillation. Standard endoscopy was followed by magnification endoscopy and repeated after acetic acid spraying. Surface patterns were characterized before and after acetic acid spraying. The observed surface patterns were compared with histological results obtained from a single targeted biopsy specimen of each pattern. RESULTS: The overall prevalence of CIM was 34.8% (86/247 patients). After excluding 52 patients because of endoscopic evidence of Barrett's esophagus, 195 patients were eligible for participation in the study. In the study group, CIM was detected in 86 patients (44.1%) in targeted biopsy samples. No dysplasia was identified. Enhanced magnification endoscopy detected four different patterns of the mucosal surface: I) round pits, II) reticular, III) villous, and IV) ridged. The yields of detection of intestinal metaplasia according to endoscopic patterns were I) 0%, II) 5.3% (odds ratio = 0.05), III) 57.7% (odds ratio = 7.5, p = 0.0001), and IV) 95.8% (odds ratio = 42.8, p = 0.0001). CONCLUSIONS: CIM is more common than previously reported. Enhanced magnification endoscopy identifies two characteristic endoscopic patterns, villous (pattern III) and ridged (pattern IV), with outstanding clarity and resolution that correlate with histological identification of CIM with a single targeted biopsy sample. Enhanced magnification endoscopy will permit longitudinal studies of an entity that can be identified endoscopically.

Acetic Acid↗
PubMed2001

Life expectancy as a summary of mortality in a population: statistical considerations and suitability for use by health authorities.

OBJECTIVE: To investigate the sampling distribution and usefulness of expectation of life in comparisons of mortality at health district level or below. DESIGN: Derivation of a formula for the variance of the expectation of life, confirmation of the result and generation of the sampling distribution by Monte Carlo simulation; comparison of expectation of life with standardised mortality ratio (SMR) and other summary indices of mortality. SETTING: A health district in Trent Region, England. SUBJECTS: Routinely available mortality statistics at electoral ward level and above. MAIN RESULTS: Given reasonable and simple assumptions the sampling distribution of the expectation of life is approximately normal. Expectation of life shows a high negative correlation with SMR even if the oldest age band for the SMR is open ended. CONCLUSIONS: Where sampling error is an issue, inference concerning differences in mortality rates between populations can be based on expectation of life, which is better for illustrative purposes than SMR. The formula for the variance of the expectation of life is more complex however. If the final age band is open ended, its lower bound should be as high as possible to avoid misleading results caused by hidden differences in age structure.

Age Factors↗
PubMed1976

[Viable bacterial counts by agar-droplet technique (author's transl)].

This paper deals with 1) Analysis of the agar droplet technique for viable bacterial counts with respect to a new technical aid (Colworth DROPLETTETM); 2) Comparison of the results obtained from two conventional plate count techniques and the agar-droplet method; 3) Examples for the practical use of this new technique. As a helpful aid for the agar-droplet technique there now exists an apparatus (Colworth DROPLETTETM, Fig.1) which facilitates dilution and dispension of bacteria containing agar, as well as counting of colonies grown in agar droplets. Precision and reproducibility of the diluter/dispenser was found to be within the limits of the usual sampling error (Tab.1, Fig. 2, Fig. 3). The visibility of colonies grown in agar droplets is improved by a ten-fold enlargement on the ground glass screen of the viewer (Fig. 7). In order to obtain droplets of equal size a standardised dropping-technique is required. The fluid agar must not exceed a constant temperature of 50 degrees C as otherwise four of the five species tested (Staph. aureus, E. coli, Kl. aerogenes, Ps. aeruginosa and Enterococci) were significantly reduced in number during the manipulation (Fig. 4, Fig. 5). Agar droplet technique, flooding technique and pour plates gave similar results with gram-positive and gram-negative bacteria from medical routine materials. Comparing the arithmetic means, viable counts of Staph. aureus were slightly higher from pour plates while E. coli and Kl. aerogenes gave the highest counts on flooded plates (Tab. 8-11). All of the three methods produced relatively too low counts when the number of bacteria per sample surmounted 300. Counts below 10 allow only a very poor estimation of the actual number of bacteria (Tab. 12). The variability of droplet counts with bacterial numbers higher than 25 was less then the one of corresponding plate counts (Tab. 14-16). Significant savings in materials, labour and incubator space are made with the agar droplet method. As examples for the practical use of the new method the results of the kinetics of thermally inactivated as well as of growing bacteria are presented.

Agar↗
PubMedDate not supplied

Probability based diagnostic biopsy specimens as predictors of tumor grade and stage found.

The Gleason score of prostatic adenocarcinoma in biopsy specimens was compared with the Gleason score of corresponding radical prostatectomy specimens from 78 patients with localized prostate cancer. Grading errors were found to be significant for well-differentiated (Gleason score 2-4) tumors. The accuracy was 6 (23%) for Gleason scores of 2-4 on needle biopsy. All of the Gleason scores of 8-10 on needle biopsy were graded correctly. When the preoperative Gleason score was <7, 20 (37%) patients had organ-confined lesions, while when preoperative Gleason score > or = 7, 5 (21%) patients were confined to the prostate. Discrepancies between the Gleason score of the biopsy material and prostatectomy specimens were larger for biopsy specimens with low Gleason scores than for biopsy specimens with high Gleason scores. Large differences existed between the Gleason histologic scores of the biopsy and prostatectomy specimens when only a single microscopic focus of the tumor in the biopsy specimen is low grade. Consequently, when tumor grade influences the clinical management of prostate cancer, patients with limited biopsy material, provided this material is not poorly differentiated, should probably undergo repeated biopsy to reduce the likihood of tumor sampling error. This awareness influences treatment policy, particularly for the watchful waiting criteria of prostate cancer.

Adenocarcinoma↗
PubMed2002

Reliability of chronic allograft nephropathy diagnosis in sequential protocol biopsies.

BACKGROUND: Chronic allograft nephropathy (CAN) progresses rapidly during the first few months and slowly thereafter. Although the presence of CAN in protocol renal biopsies is a predictor of outcome, the reliability of this diagnosis according to Banff criteria has not been characterized. METHODS: Renal lesions were evaluated according to the Banff criteria in sequential protocol biopsies performed at 4 and 14 months in 310 biopsies obtained from 155 patients. RESULTS: CAN progressed from 40 to 53% (P=0.001) while serum creatinine remained stable (146 +/- 44 vs. 147 +/- 48 micromol/L, P=NS). Graft survival in patients with and without CAN in the first biopsy was 74 versus 91% (P < 0.05), and in the second biopsy 75 versus 94% (P < 0.05). In 54 patients (35%) no CAN was present in both biopsies, 39 (25%) showed progression to CAN, 19 (12%) showed regression of CAN, and 43 (28%) showed CAN in both biopsies. Graft survival was: 100%, 81.6%, 82.6% and 69.4%, respectively (P < 0.01). Assuming that CAN does not regress and sampling error is normally distributed, we estimated that 25% of biopsies cannot be properly classified. CONCLUSIONS: The increase in the incidence of CAN between the 4th and 14th month is lower than the proportion of misclassified biopsies. Thus, monitoring the progression of CAN by means of two sequential biopsies at 4 and 14 months is inaccurate. We suggest that progression of scarring be monitored by means of a donor and a protocol biopsy performed during the first year evaluated with a quantitative approach.

Adult↗
PubMed2004

Valid symptom reporting at upper endoscopy in a random sample of the Swedish adult general population: the Kalixanda study.

BACKGROUND: Upper oesophagogastroduodenoscopy is considered to be the gold standard for upper gastrointestinal disease assessment, but is currently seldom used in epidemiological studies. One concern is that the procedure may bias sampling among volunteers in a general adult population. The aim of this study was to explore whether the procedure affects symptom reporting. METHODS: A random sample of 3000 adults aged 20-81 years (mean age 50.4), from two Swedish municipalities (n=21,610) was surveyed using a validated postal questionnaire (the Abdominal Symptom Questionnaire) assessing gastrointestinal symptoms. A subsample of the responders was invited, in random order, to undergo an upper endoscopy and repeated symptom reporting using the same questionnaire, as well as a serology test for Helicobacter pylori. RESULTS: The response rate to the initial questionnaire was 74.2% and the participation rate for those eligible for the upper endoscopy was 73.3% (n = 1001, mean age 54.0 years, 48.8% male). No major social or symptom sampling error was encountered from the selection process, with the exception of an excess of symptom reporters among the youngest subjects. The prevalence of reflux symptoms, dyspeptic symptoms and irritable bowel symptoms was 40%, 37.6% and 29.6%, respectively, which is relatively high, but in no way extreme. CONCLUSIONS: The upper endoscopy survey strategy was successful. The response rate was high and there was no major selection bias of clinical relevance. The cohort selected for this study appears to be representative of the general Swedish adult population.

Adult↗
PubMed2006

Modeling Sage data with a truncated gamma-Poisson model.

BACKGROUND: Serial Analysis of Gene Expressions (SAGE) produces gene expression measurements on a discrete scale, due to the finite number of molecules in the sample. This means that part of the variance in SAGE data should be understood as the sampling error in a binomial or Poisson distribution, whereas other variance sources, in particular biological variance, should be modeled using a continuous distribution function, i.e. a prior on the intensity of the Poisson distribution. One challenge is that such a model predicts a large number of genes with zero counts, which cannot be observed. RESULTS: We present a hierarchical Poisson model with a gamma prior and three different algorithms for estimating the parameters in the model. It turns out that the rate parameter in the gamma distribution can be estimated on the basis of a single SAGE library, whereas the estimate of the shape parameter becomes unstable. This means that the number of zero counts cannot be estimated reliably. When a bivariate model is applied to two SAGE libraries, however, the number of predicted zero counts becomes more stable and in approximate agreement with the number of transcripts observed across a large number of experiments. In all the libraries we analyzed there was a small population of very highly expressed tags, typically 1% of the tags, that could not be accounted for by the model. To handle those tags we chose to augment our model with a non-parametric component. We also show some results based on a log-normal distribution instead of the gamma distribution. CONCLUSION: By modeling SAGE data with a hierarchical Poisson model it is possible to separate the sampling variance from the variance in gene expression. If expression levels are reported at the gene level rather than at the tag level, genes mapped to multiple tags must be kept separate, since their expression levels show a different statistical behavior. A log-normal prior provided a better fit to our data than the gamma prior, but except for a small subpopulation of tags with very high counts, the two priors are similar.

Algorithms↗
PubMed2003

Implementation and applications of bootstrap methods for the National Immunization Survey.

In complex probability sample surveys, numerous adjustments are customarily made to the survey weights to reduce potential bias in survey estimates. These adjustments include sampling design (SD) weight adjustments, which account for features of the sampling plan, and non-sampling design (NSD) weight adjustments, which account for non-sampling errors and other effects. Variance estimates prepared from complex survey data customarily account for SD weight adjustments, but rarely account for all NSD weight adjustments. As a result, variance estimates may be biased and standard confidence intervals may not achieve their nominal coverage levels. We describe the implementation of the bootstrap method to account for the SD and NSD weight adjustments for complex survey data. Using data from the National Immunization Survey (NIS), we illustrate the use of the bootstrap (i). for evaluating the use of standard confidence intervals that use Taylor series approximations to variance estimators that do not account for NSD weight adjustments, (ii). for obtaining confidence intervals for ranks estimated from weighted survey data, and (iii). for evaluating the predictive power of logistic regressions using receiver operating characteristic curve analyses that account for the SD and NSD adjustments made to the survey weights.

Analysis of Variance↗
PubMed2004

Excess risk thresholds in ultrasound safety studies: statistical methods for data on occurrence and size of lesions.

Concerns about the safe use of clinical ultrasound (US) at diagnostic pressure levels (below a mechanical index, or MI, = 1.9) have stimulated considerable research in US risk assessment. The objective of the present study was to develop probability-based risk thresholds for US safety studies, to present statistical methods for estimating the thresholds and their standard errors and to compare these methods with the analysis based on a piecewise linear ("hockey stick") model. The excess risk at exposure level x > 0 was defined as the relative increase in the probability of a lesion at that level compared with the background probability of a lesion at exposure x = 0. The risk threshold was then defined as the exposure level at which the excess risk exceeded a specified level (e.g. 5% or 50%). Thus, given pressure-dependent estimates of the excess risk, the thresholds were estimated by solving the risk equation to obtain the pressure at which the target level of excess risk occurs. Threshold estimates of this type have been developed extensively in the literature for incidence (presence or absence) data. Only recently, however, have excess risk threshold estimates been derived for data in which lesion size (depth, surface area) is measured if present and a zero is recorded if the lesion is absent. Tobit regression was used to estimate pressure-dependent percentiles of the size distribution, and the excess risks were estimated from the tobit probability of a positive-valued response. The tobit model provides a well-established approach to modeling data constrained to be nonnegative. Solving the risk equation for the tobit model leads to risk threshold estimates that incorporate the information on size of observed lesions. Results using these probability-based risk estimates were compared with results for a piecewise linear ("hockey stick") model, which has also been used in the US safety literature, although it does not explicitly address the nonnegativity constraint in the sampling model. The comparisons were carried out for data from two previously published studies, from different laboratories, on US-induced lung hemorrhage. The thresholds derived from logistic regression of lesion occurrence and tobit regression of lesion size were quite consistent with each other and within sampling error. The hockey stick thresholds, defined as the exposure level at which the piecewise linear model for the probability of the expected size of a lesion bends upward, corresponded to quite different excess risk values for incidence (lesion occurrence) compared with size (lesion surface area or depth), although these methods have been developed previously for both types of data. The use of probability-based excess risk thresholds is recommended to obtain consistent incidence vs. size thresholds and to ensure that the thresholds are well-defined and interpretable independent of the details of the statistical model.

Animals↗
PubMed2006

Is there a role of sentinel lymph node biopsy in ductal carcinoma in situ?: analysis of 587 cases.

BACKGROUND: The role of sentinel lymph node biopsy (SLNB) in patients with a core needle-biopsy diagnosis of ductal carcinoma in situ (DCIS) has been intensely debated. Core needle-biopsy has an inherent sampling error leading to histologic underestimation of invasive disease. If SLNB is not performed at the time of the definitive operative procedure, patients found to have an invasive cancer, will require a second operative procedure. The study was designed to determine when the risk of finding invasive disease on final pathology in patients with an initial diagnosis of DCIS was sufficiently high to justify the use of SLNB. METHODS: We identified 587 women with an initial core needle-biopsy diagnosis of DCIS in the prospective Breast Test Wales (BTW) database from 1995 through 2005. A variety of clinical, mammographic and histologic features were identified and correlated with the presence of invasion at excision using univariate and multivariate analyses. RESULTS: Median age of patients at the time of diagnosis was 58 years (range 41 to 83 years). 201 patients (36%) were treated by mastectomy and 354 (64%) by breast conservation surgery. 220 of 587 patients (38%) were found to have invasive disease on final pathology. On univariate analysis, the rate of upstaging was related to the presence of a clinically palpable mass and size of the mass (both p<0.0001, Mann-Whitney test); mammographic presence of a mass and size of the mass (both p<0.0001, Mann-Whitney test). Multivariate logistic regression analysis revealed 2 independent predictors of invasive cancer on final pathology: mass on clinical examination (odds ratio [OR], 5.09; p<0.0001) and mammographic mass (OR, 7.37; p<0.0001). Age, grade of DCIS, microinvasion and presence of comedonecrosis did not help in distinguishing between patients with DCIS and those upstaged to invasive carcinoma at definitive surgery. Axillary nodal staging (four node sampling or clearance) was done at the time of surgery in 269 patients. Axillary nodal metastases were found in 35 of 269 patients (13%). All 35 patients had invasive carcinoma on final pathology. CONCLUSION: The indiscriminate use of SLNB in patients with DCIS seems excessive. Our study suggests that patients with a mass on clinical examination or mammogram have an increased risk of invasive disease at the time of definitive operative procedure and should undergo SLNB at the initial procedure. In addition, SLNB should be performed in patients undergoing mastectomy because mastectomy precludes SLNB if invasive disease is subsequently discovered.

Adult↗
PubMed2000

Influence of time interval and number of blood samples on the error in renal clearance determination using a mono-exponential model: a Monte Carlo simulation.

Mono-compartmental analysis based on 2- and 4-h blood samples (BS) of 51Cr-EDTA (EDTA, ethylenediaminetetraacetic acid) is commonly used for the calculation of the glomerular filtration rate (GFR). The purposes of this study were to estimate the magnitude of error in clearance induced by errors in the time of sampling and activity measurement; to estimate the impact of changing the interval between the BS; and to assess the influence of a higher number of BS in reducing the error. A model of mono-exponential curves based on a finite number of BS was created. Normally distributed random errors were introduced in the time of sampling and activity measurement. In a first step, three different time intervals were used; in a second step, seven different numbers of BS were used, all taken between 120 and 240 min. For each setting, the random errors were successively introduced 200 times and the coefficients of variation (CV) of the calculated clearances were determined. Variable errors in clearance were induced by errors in the time of sampling and activity measurement. In general, the observed errors were higher for high and low clearance, with lower errors for moderately reduced clearances. The errors in indicating the time of sampling played an important role for high clearance, whereas the errors in activity measurements led to important errors for low clearance. Prolonging the interval from 1 to 2 h resulted generally in an important decrease in error, except in the range 60-100 ml x min(-1). Prolonging the interval from 2 to 3 h resulted in only a small additional decrease in error, except for very low clearance. Errors in indicating the time of sampling and in activity measurements induce errors in clearance determination. These errors cannot be significantly reduced by simply increasing the number of BS or by prolonging the interval between the samples. It is probably better, in most cases, to keep using the 2-4-h method and to take extreme care when indicating the time of sampling and when measuring the activity, instead of increasing the number of samples or lengthening the procedure.

Algorithms↗
PubMed2000

Public attitudes of independent dental hygiene practice.

PURPOSE: The three main objectives of this study were to assess if the Alberta, Canada public perceives dental hygienists as competent to practice without the supervision of a dentist, whether or not they would choose to be treated by independent dental hygienists, and if they believed that these services should be covered by dental insurance. METHODS: The University of Alberta population research lab conducted a random digit dialing telephone survey of Alberta residents, regarding access to dental hygiene services and willingness to visit an independent dental hygiene practitioner. There were 1,202 residents (49.6% males and 50.4% females, 18-64 years), evenly distributed among urban and rural areas, who were interviewed. The estimated sampling error, at the 95% confidence level, was accurate + 2.9%. RESULTS: Of the respondents, 65.8% stated that they would visit an independent dental hygienist and that dental hygienists should have the ability to provide services, within their scope of practice, without being supervised. This response was consistent, irrespective of the geographic area, gender or income. When asked about their reasons for choosing an independent dental hygienist, 68.8% believed visiting a dental hygienist is important in the healthy treatment of their mouth, while 58.4% wanted the freedom to choose, and 56.3% believed dental hygiene care would save them money. They also indicated that they would visit an independent dental hygienist in a variety of sites, including a health center (45%), a mobile clinic (21.5%), an independent practice site (45%), and in a dentist's office (64.9%). Ninety-two percent of the respondents said that independent dental hygiene services should be covered by dental insurance. CONCLUSION: The results show that the public supports dental hygienists gaining independent practice, and that they trust the level of care provided by the dental hygiene profession.

Adolescent↗
PubMed2005

Health information systems in humanitarian emergencies.

Health information systems (HIS) in emergencies face a double dilemma: the information necessary to understand and respond to humanitarian crises must be timely and detailed, whereas the circumstances of these crises makes it challenging to collect it. Building on the technical work of the Health Metrics Network on HIS and starting with a systemic definition of HIS in emergencies, this paper reviews the various data-collection platforms in these contexts, looking at their respective contributions to providing what humanitarian actors need to know to target their intervention to where the needs really are. Although reporting or sampling errors are unavoidable, it is important to identify them and acknowledge the limitations inherent in generalizing data that were collected in highly heterogeneous environments. To perform well in emergencies, HIS require integration and participation. In spite of notable efforts to coordinate data collection and dissemination practices among humanitarian agencies, it is noted that coordination on the ground depends on the strengths and presence of a lead agency, often WHO, and on the commitment of humanitarian agencies to investing resources in data production. Poorly integrated HIS generate fragmented, incomplete and often contradictory statistics, a situation that leads to a misuse of numbers with negative consequences on humanitarian interventions. As a means to avoid confusion regarding humanitarian health statistics, this paper stresses the importance of submitting statistics to a rigorous and coordinated auditing process prior to their publication. The audit trail should describe the various steps of the data production chains both technically and operationally, and indicate the limits and assumptions under which each number can be used. Finally emphasis is placed on the ethical obligation for humanitarian agencies to ensure that the necessary safeguards on data are in place to protect the confidentiality of victims and minority groups in politically sensitive contexts.

Altruism↗
PubMed1976

Fume-induced fluorescence in diagnosis of nasal neuroblastoma.

Nasal neuroblastoma, esthesioneuroblastoma, is frequently difficult to distinguish from the more common poorly differentiated epidermoid carcinoma of the nasal cavity and nasopharynx. We present a simple alternate method to electron microscopy, formaldehyde-fume-induced fluorescence, to demonstrate biogenic amine granules in neoplastic cells. This method is more specific and more sensitive, since it reveals the presence of biogenic amines, not merely membrane-bound granules, and it deals with larger quantities of tissue, thus avoiding some of the sampling errors inherent in electron microscopy. We also describe the histochemical relationship of this tumor to other neural crest neoplasms.

Formaldehyde↗
PubMed1998

Hippocampal volume reduction in schizophrenia as assessed by magnetic resonance imaging: a meta-analytic study.

BACKGROUND: Although many quantitative magnetic resonance imaging studies have found significant volume reductions in the hippocampi of patients with schizophrenia compared with those of normal control subjects, others have not. Therefore, the issue of hippocampal volume differences associated with schizophrenia remains in question. METHODS: Two meta-analyses were conducted to reduce the potential effects of sampling error and methodological differences in data acquisition and analysis. Eighteen studies with a total patient number of 522 and a total control number of 426 met the initial selection criteria. RESULTS: Meta-analysis 1 yielded mean effect sizes of 0.37 (P<.001) for the left hippocampus and 0.39 (P<.001) for the right, corresponding to a bilateral reduction of 4%. Meta-analysis 2 indicated that the inclusion of the amygdala in the region of interest significantly increased effect sizes across studies (effect size for the left hippocampus and amygdala, 0.67; for the right, 0.72), whereas variables such as illness duration, total slice width, magnet strength, the use of the intracranial volume as a covariate, measurement reliability, and study quality did not. No laterality differences were observed in these data. CONCLUSIONS: Schizophrenia is associated with a bilateral volumetric reduction of the hippocampus and probably of the amygdala as well. These findings reinforce the importance of the medial temporal region in schizophrenia and are consistent with frequently reported memory deficits in these patients. Future quantitative magnetic resonance imaging studies evaluating the hippocampal volume should measure the hippocampus and amygdala separately and compare the volumetric reduction in these structures to that observed in other gray matter areas.

Adult↗
PubMed1986

Mammography of women with suspicious breast lumps.

We analyzed 342 women who had suspicious breast lumps to determine if preoperative mammography could improve the malignancy yield of biopsy procedures. The number of women with cancer of the breast and false-negative mammogram reports ranged from 11% to 25%, depending on how equivocal mammogram reports were interpreted. Therefore, women with clinically suspicious breast lumps should undergo biopsy regardless of mammographic findings. A significant difference in the mean (+/- SD) predictive value of a positive mammogram existed between women above and below the age of 50 years (80 +/- 8 vs 43 +/- 14) because of the age-specific relative prevalence of benign and malignant disease, and because mammography had difficulty distinguishing between benign and malignant lumps (specificity, 70). Preoperative mammography of women with suspicious breast lumps is indicated to screen for occult carcinoma, to prevent biopsy sampling errors, and to judge the adequacy of lumpectomy if the lesion is malignant.

Adult↗
PubMed1991

Touch preparation cytology of breast lumpectomy margins with histologic correlation.

Residual microscopic disease after lumpectomy for breast cancer may cause significant local recurrence. We evaluated one hundred fourteen consecutive breast lumpectomy margins in this study by touch preparation cytology. Cytologic preparations were intraoperatively correlated with gross and frozen section results and subsequently with permanent histologic sections of representative margins. Three specimens were cytologically unsatisfactory and 86 yielded benign findings, while material suggestive or diagnostic of malignancy was obtained from 25 specimens. Gross, frozen section, and permanent histologic margins were positive in 10, 17, and 22 cases, respectively. There were three false-positive touch preparation cytologic results, while frozen section specimens were false-negative in five cases. Sensitivity and specificity of touch preparation cytology were 100% and 96.6%, respectively, with a diagnostic accuracy of 97.3%. Touch preparation cytologic examination rapidly and reliably evaluates lumpectomy margins and overcomes sampling errors and artifacts related to frozen section evaluation. This technique currently complements frozen section evaluation of lumpectomy margins as part of a protocol aimed at reducing local recurrence of breast cancer.

Adult↗