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False-positive Diagnoses (false-positive + diagnosis)

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Medical Sciences	90%

Selected Abstracts

Pancreatic mucinous lesions: A retrospective analysis with cytohistological correlation

DIAGNOSTIC CYTOPATHOLOGY, Issue 11 2006
Jing Zhai M.D., Ph.D.
Abstract The diagnosis of mucinous pancreatic lesions, which include mucinous noncystic adenocarcinoma, intraductal papillary mucinous neoplasm (IPMN), mucinous cystic neoplasm (MCN), and mucinous metaplasia, is critical, given different clinical management and prognosis. This retrospective study is done to assess the cytological features and pitfalls associated with these entities in cytological samples. A search for pancreatic cytology specimens with histological confirmation of the various pancreatic mucinous lesions was done from 1988 to 2005: 9 mucinous adenocarcinoma, 14 IPMN, 11 MCN, and 3 mucinous metaplasia. The majority (35/37) had been endoscopic ultrasound-guided fine-needle aspirations. The cellularity, background extracellular mucin, epithelial architecture, mucinous nature of the epithelium, cell shape, and nuclear features were evaluated on the cytology material. Of the 22 cytological features evaluated, the presence of three-dimensional clusters, micropapillary structures, and nuclear atypia, which includes nuclear crowding, increased N/C ratio, anisonucleosis, nuclear membrane contour irregularity, clumpy chromatin, and prominent nucleoli, was found to be consistently associated with mucinous adenocarcinoma. There were no statistically significant cytological features, which helped in differentiating IPMN, MCN, and mucinous metaplasia. There was a relatively high false-positive rate in the IPMN group (5/14, 36%). Review of the histological specimen showed severe dysplastic epithelial change in these cases. One false-positive case of mucinous metaplasia (1/3, 33%) showed marked intraepithelial acute inflammation. The cytological diagnosis of mucinous pancreatic lesions remains challenging, except for mucinous noncystic adenocarcinoma. The findings were largely nonspecific in the differentiation between IPMN, MCN, mucinous metaplasia, and incidentally sampled gastrointestinal epithelium. False-positive diagnosis of adenocarcinoma occurs not infrequently in the setting of IPMN with severe dysplastic epithelial change and in lesions with associated acute inflammation, and can be a pitfall in the diagnosis of these lesions. Diagn. Cytopathol. 2006;34: 724,730. © 2006 Wiley-Liss, Inc. [source]

Diagnostic accuracy of cytology and immunocytology in carcinomatous effusions

CYTOPATHOLOGY, Issue 4 2008
G. Metzgeroth
Background:, Immunocytology substantially improves the diagnostic accuracy of conventional cytology in the diagnosis of carcinomatous effusions. Due to the unequivocal characterization of the various cell populations, a sensitivity of 92% and specificity of 100% was achieved by immunocytology, examining samples of 1234 serous effusions. Objective:, Cytology plays a central role in the aetiological clarification of serous effusions. The sensitivity of this method for the diagnosis of carcinomatous effusions varies between 40% and 80%. The aim of the present study was to investigate whether immunocytology substantially improves the diagnostic quality of the cytological examination in the diagnosis of carcinomatous effusions. Method:, Consecutive serous effusions were examined by conventional cytology and by immunocytology. The immunocytological examination was performed on smears, using a standard panel of three antibodies against pancytokeratin, human epithelial antigen 125 and calretinin. Results:, Altogether, 1234 effusion samples were examined. A total of 603 effusions were caused by carcinomas, five by malignant mesotheliomas, 11 by malignant lymphomas and 615 by non-malignant disorders. In conventional cytology, carcinomatous effusions were correctly diagnosed in 314 samples, corresponding to a sensitivity of 52%. In 31 specimens (5%) tumour cells without further specification were described and in 161 samples (27%) the presence of tumour cells was suspected (84% overall sensitivity). A total of 97 carcinomatous effusions (16%) were diagnosed false-negatively and 50 (8%) of the 615 non-malignant effusions false-positively (92% specificity). In immunocytology, 561 carcinomatous samples were correctly diagnosed, representing a sensitivity of 93%. In six cases (1%) the presence of tumour cells was suspected. A total of 36 carcinomatous effusions (6%) were diagnosed false-negatively (94% over-all sensitivity). Out of the 615 non-malignant specimens, there were no false-positive diagnoses (100% specificity). Conclusion:, Immunocytology is a simple, cost-effective, routinely practicable method which substantially improves the diagnostic accuracy of conventional cytology in the diagnosis of carcinomatous effusions. Therefore, we recommend the use of immunocytology in all those cases where cytology on its own is not completely unequivocal. [source]

Cytohormonal and morphological alterations in cervicovaginal smears of postmenopausal women on hormone replacement therapy

DIAGNOSTIC CYTOPATHOLOGY, Issue 10 2006
Sanjay Gupta M.D.
Abstract The objective of the study was to study the cytohormonal and morphological alterations in cervicovaginal smears associated with the use of hormone replacement therapy (HRT) and to assess the utility of vaginal cytology in determining the response to HRT. Ninety postmenopausal women (30 on estrogen,progesterone combination (HRT) for 1 to 24 mo (user 1), 30 on estrogen therapy (ERT) for 1 to 44 mo (user 2), and 30 not on any hormones (nonusers)) were included in the cross-sectional study. Their lateral vaginal wall smears and cervical smears were examined for hormonal and morphological assessments, respectively. The smear pattern showed predominance of parabasal cells in 46.6% of nonusers, while none of the users had >70% parabasal cells. A high percentage (>70%) of intermediate cells was found in 46.6% of users and only in 16.6% of nonusers. A high maturation value (MV) was found in more than 75% of users but in only 16.6% of nonusers. The women with high MV (>50) were significantly less symptomatic than did nonusers. Atrophic changes were present in cervical smears of 14/20 (46.6%) nonusers when compared with 1/60 (1.66%) users. Atypical squamous cells of undetermined significance (ASC-US) were diagnosed in seven users and three nonusers. It persisted on follow-up in four users and one nonuser. Histology revealed one mild dysplasia among users. Lactobacilli were more frequently observed in users. The cytohormonal pattern on vaginal smears correlates well with the response to hormonal therapy and clinical symptoms. Awareness of the morphological alterations associated with the use of replacement hormones would enable the cytologists to reduce the false-positive diagnoses while evaluating postmenopausal smears. Diagn. Cytopathol. 2006;34:676,681. © 2006 Wiley-Liss, Inc. [source]

Evaluation of decision criteria for detection of spinal cord compression based on cervical myelography in horses: 38 cases (1981,2001)

EQUINE VETERINARY JOURNAL, Issue 1 2004
J. Van Biervliet
Summary Reasons for performing study: Different criteria have been described based on height reduction of the total myelographic contrast column and components of it as tests for compression of the spinal cord due to cervical stenotic myelopathy (CSM). Fifty percent height reduction of the dorsal myelographic column (DMC), <2 mm empiric height of the DMC and a 40% reduction of the ratio of stenosis calculated based on the height reduction of the entire dural diameter (DD) have been described as decision criteria for considering the test result positive. The reasons for selecting these decision criteria or their accuracies have rarely been reported. Objectives: To evaluate the accuracy of diagnostic criteria based on reduced height of the total myelographic column and components of it for diagnosing extradural spinal cord compression using different decision criteria, and make recommendations for consistent myelographic interpretation in horses suspected of having CSM. Methods: Four measurements were obtained by 2 readers in a retrospective sample population of 38 horses in which both cervical myelography and histopathological examination of the cervical spinal cord were performed. The prevalence of CSM in the sample was 50%. At intervertebral sites, the minimum heights of the DD and DMC were measured. At intravertebral sites, the maximum heights of the entire DD and DMC were obtained. Percent height reductions of the DMC and DD were determined as the ratio of minimum intervertebral height to maximum intravertebral height within the next cranial vertebra. Histological examination was used as the gold standard for determining the actual site of spinal cord compression. Sensitivity and specificity for the diagnostic criteria were estimated at each site in neutral and flexed neck positions using several different decision criteria. Conclusions: At C6-C7, in neutral or flexed neck position and using 20% reduction of DD, the test was highly sensitive and specific for CSM. At other sites, reduced height of the myelographic column generally was not accurate for diagnosing extradural spinal cord compression. Using 20% reduction of DD in neutral position at the mid-cervical sites, the test had only low sensitivity and high specificity. Flexion of the neck appeared to increase detection of spinal cord compression in the mid-cervical region, but also substantially increased the frequency of false-positive diagnoses. Potential relevance: By using the reported sensitivity and specificity estimates, readers may decide on a decision criterion for diagnosis of extradural spinal cord compression due to CSM. However, in planning a surgical correction, it is difficult to define a decision criterion that combines acceptable sensitivity and specificity, especially at the mid-cervical sites. [source]

Prenatal diagnosis by rapid aneuploidy detection and karyotyping: a prospective study of the role of ultrasound in 1589 second-trimester amniocenteses

PRENATAL DIAGNOSIS, Issue 10 2004
Wing Cheong Leung
Abstract Background Reliable methods are available for rapid aneuploidy detection (RAD) for the prenatal diagnosis of trisomies 21, 18 and 13. This study examines the potential advantages and limitations of using RAD as a replacement rather than as an adjunct to traditional karyotyping. Methods One thousand five hundred and eighty-nine consecutive pregnancies referred for cytogenetic assessment were offered RAD (FISH or QF-PCR) as an adjunct to traditional karyotyping. The results of these two processes were compared, and the effects of three policies for cytogenetic evaluation were determined: RAD alone, a combination of RAD for all and traditional karyotyping for cases with ultrasound anomalies or a policy of RAD and traditional karyotyping in all cases. Results RAD was uninformative because of maternal-cell contamination in 37 (2.3%) cases compared to 4 (0.3%) cases of culture failure in traditional karyotyping. RAD and traditional karyotyping results were concordant in 1526 of 1548 (98.6%) cases. All non-mosaic cases of trisomies 21, 18 and 13 and cases of triploidy were correctly identified by RAD, and there were no false-positive diagnoses. The gold standard of a traditional karyotype in each case would have detected all chromosomal abnormalities. A policy of RAD alone would have identified 60 of 73 (82%) clinically important chromosomal abnormalities. The addition of a full karyotype for cases with evidence of ultrasound abnormalities would have improved detection to 95%. Conclusion A policy offering RAD to all patients, but restricting traditional karyotyping to cases with ultrasound anomalies, would reduce the number of traditional karyotypes requested by 70%, but maintain a 95% detection rate for all clinically important chromosomal abnormalities. Further studies are required to determine whether similar results could be obtained in district general hospital units and to determine whether this approach would be acceptable to health professionals and patients. Copyright © 2004 John Wiley & Sons, Ltd. [source]

The Use of Stereotaxic Core Biopsy and Stereotaxic Aspiration Biopsy as Diagnostic Tools in the Evaluation of Mammary Calcification

THE BREAST JOURNAL, Issue 6 2000
Joan F. Cangiarella MD
Abstract: We compared stereotaxic fine needle aspiration biopsy (SFNA) with stereotaxic core needle biopsy (SCB) in the evaluation of radiographically clustered mammary microcalcification, a common finding at screening mammography. Over a 4-year period, 181 specimens were obtained from 175 patients who underwent both SFNA and SCB of clustered microcalcification. Aspiration and core biopsies were performed by radiologists at a community-based diagnostic radiology facility. All aspiration smears were air dried, stained on site, and assessed for adequacy by the radiologists, then sent to the cytopathologists at New York University for interpretation. Core biopsy specimens were formalin fixed, paraffin embedded, hematoxylin and eosin stained, and interpreted by surgical pathologists at a community hospital. Of 181 SFNA specimens, 133 (74%) were benign, 18 (10%) were atypical, 13 (7%) were suspicious, and 16 (9%) were malignant. One (0.5%) aspiration biopsy was nondiagnostic. Excisional biopsies were performed after 12 benign SFNAs and in 46 of the 47 cases with an atypical, suspicious, or malignant diagnosis on SFNA. Mammographic follow-up in 111 of the 133 cases (92%) diagnosed as benign showed no radiologic change (mean 29.2 months, range 6,60 months). The false-negative rate for cancer was 4% (6 cases) for SFNA alone. There were no false-positive diagnoses for SFNA. There was one false-positive diagnosis on core biopsy [focal cribriform ductal carcinoma in situ (DCIS)], which at excisional biopsy and correlation with the core biopsy was diagnosed as ductal hyperplasia; the false-negative rate for cancer was 8% (13 cases) for SCB alone. Aspiration biopsy identified calcification in 180 procedures, core needle biopsy revealed calcification in 170. SFNA was superior to SCB for the confirmation of clustered mammary microcalcification (99% versus 94%) and in the identification of cancer associated with microcalcification (false negative rate of 4% versus 8%). Patients with benign findings on stereotaxic aspiration and core biopsy can reasonably be followed mammographically. [source]

Prevalence of and screening for serious spinal pathology in patients presenting to primary care settings with acute low back pain

ARTHRITIS & RHEUMATISM, Issue 10 2009
Nicholas Henschke
Objective To determine the prevalence of serious pathology in patients presenting to primary care settings with acute low back pain, and to evaluate the diagnostic accuracy of recommended "red flag" screening questions. Methods An inception cohort of 1,172 consecutive patients receiving primary care for acute low back pain was recruited from primary care clinics in Sydney, Australia. At the initial consultation, clinicians recorded responses to 25 red flag questions and then provided an initial diagnosis. The reference standard was a 12-month followup supplemented with a specialist review of a random subsample of participants. Results There were 11 cases (0.9%) of serious pathology, including 8 cases of fracture. Despite the low prevalence of serious pathology, most patients (80.4%) had at least 1 red flag (median 2, interquartile range 1,3). Only 3 of the red flags for fracture recommended for use in clinical guidelines were informative: prolonged use of corticosteroids, age >70 years, and significant trauma. Clinicians identified 5 of the 11 cases of serious pathology at the initial consultation and made 6 false-positive diagnoses. The status of a diagnostic prediction rule containing 4 features (female sex, age >70 years, significant trauma, and prolonged use of corticosteroids) was moderately associated with the presence of fracture (the area under the curve for the rule score was 0.834 [95% confidence interval 0.654,1.014]; P = 0.001). Conclusion In patients presenting to a primary care provider with back pain, previously undiagnosed serious pathology is rare. The most common serious pathology observed was vertebral fracture. Approximately half of the cases of serious pathology were identified at the initial consultation. Some red flags have very high false-positive rates, indicating that, when used in isolation, they have little diagnostic value in the primary care setting. [source]

Respiratory cytology: Differential diagnosis and pitfalls

DIAGNOSTIC CYTOPATHOLOGY, Issue 4 2010
F.R.C.P.C., Ph.D., Reda S. Saad M.D.
Abstract Pulmonary cytology can be challenging and has its share of diagnostic pitfalls. Reactive atypia can occasionally be alarming, leading to diagnostic pitfall for a false-positive diagnosis of malignancy, even for experienced cytopathologists (Naryshkin and Young, Diagn Cytopathol 1993;9:89,97). In addition, cytologic preparations can show an absence of architectural clues, leading to diagnostic difficulties. Some conditions can cytologically as well as clinically and radiographically mimic malignancies, making these pitfalls even more frequent (Bedrossian et al., Lab Med 1983;14:86,95). A recent report stated that "no laboratory that aims to make definitive diagnoses in pulmonary cytology can be spared from false-positive results"(Policarpio-Nicolas and Wick, Diagn Cytopathol 2008;36:13,19). A false-positive finding could produce unnecessary treatment and morbidity, whereas false-negative diagnosis could result in delayed diagnosis and treatment. This review analyzes and illustrates cellular changes and benign entities that can mimic malignancy in respiratory cytology as well as neoplasms that could lead to a false-negative diagnosis. In addition, some specific challenging and difficult aspects in classification of pulmonary malignancies will be discussed. Guidelines and clues are presented to avoid such pitfalls. Diagn. Cytopathol. 2010. © 2009 Wiley-Liss, Inc. [source]

Adenocarcinoma in colonic brushing cytology: High-grade dysplasia as a diagnostic pitfall

DIAGNOSTIC CYTOPATHOLOGY, Issue 5 2001
Gordon H. Yu M.D.
Abstract Cytologic evaluation of brushing specimens obtained from the colon may be useful in the diagnosis of neoplastic and inflammatory lesions, as previous studies have reported favorable sensitivity and specificity figures for this procedure. In this study, we report our experience with 80 colonic brushings examined over a 5-yr period. Thirty cases received an atypical or malignant cytologic diagnosis. Nineteen of 20 cases diagnosed cytologically as adenocarcinoma revealed adenocarcinoma on biopsy; one case showed only adenomatous epithelium on biopsy and subsequent resection. Cases diagnosed cytologically as "atypical" or "adenomatous" showed adenocarcinoma, adenoma, and inflammatory conditions upon biopsy. Slides from 30 atypical/malignant cases were retrospectively reviewed for a number of cytomorphologic features and were correlated with the histologic diagnosis. Cases from histologically confirmed adenocarcinoma tended to show greater degrees of altered nuclear polarity, nuclear pleomorphism, membrane irregularities, and chromatin pattern alterations than those from histologically proven adenomatous or inflammatory lesions. The most likely cause of a false-positive diagnosis in this setting is sampling of an adenoma with high-grade dysplasia which fails to meet histologic criteria for adenocarcinoma (invasion of the underlying muscularis mucosae). Thus, in the second part of the study, we examined histologic sections from surgically excised adenomas to determine the frequency with which profound nuclear atypia is at least focally present, potentially resulting in a false-positive cytology diagnosis upon brushing. Slides from 51 cases were reviewed; cytologic atypia beyond that typically observed in adenomas was not observed in 43% of cases. However, profound nuclear atypia was present in 6% of cases; cytologic evaluation of a brushing specimen from these lesions may have resulted in a false-positive diagnosis of adenocarcinoma, despite the histologic diagnosis of adenoma with severe dysplasia. The remaining cases demonstrated intermediate degrees of atypia. These findings serve to quantitate the frequency with which cytohistologic discrepancies might be expected for mass lesions of the colon. Diagn. Cytopathol. 24:364,368, 2001. © 2001 Wiley-Liss, Inc. [source]