Clinical Value of Imaging Using Antibody to Alpha Fetoprotein in Germ Cell Tumours

Germ cell tumours (GCT) producing alpha fetoprotein (aFP) can be imaged by external scintigraphy after intravenous administration of radiolabelled antibody directed against aFP. Antibody imaging (AI) by this method was used in an attempt to guide surgical resection of deposits of drug-resistant or recurrent GCT. 30 patients with GCT and raised aFP in whom site of tumour was not known were investigated by AI and conventional imaging methods. All but one were heavily pretreated. Where tumour appeared localised, resection was attempted. Tumour was found in all sites positive by both AI and conventional imaging. AI produced false-positive results in one of 30 patients and falsenegative results in 9 patients. Computerised tomography was false-positive in one case and false-negative in three. In these patients, AI gave true-negative and true-positive results, respectively. Of 11 patients with positive AI in whom resection was attempted, 6 achieved sustained complete response with up to 5 years follow-up. We conclude AI and conventional imaging methods to be complementary in selection for surgery of patients with drug-resistant or recurrent GCT.

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MRI in the Early Detection of Breast Cancer in Women with High Genetic Risk

Tumori Journal ◽

10.1177/030089160609200609 ◽

2006 ◽

Vol 92 (6) ◽

pp. 517-523 ◽

Cited By ~ 33

Author(s):

Giovanna Trecate ◽

Daniele Vergnaghi ◽

Siranuosh Manoukian ◽

Silvana Bergonzi ◽

Gianfranco Scaperrotta ◽

...

Keyword(s):

Breast Cancer ◽

Early Detection ◽

False Positive ◽

Genetic Risk ◽

Brca2 Mutation ◽

False Negative ◽

Conventional Imaging ◽

High Genetic Risk ◽

Second Look ◽

Positive Results

Aims and background Women with BRCA1 or BRCA2 germline mutations have an elevated risk of developing breast and/or ovarian cancer. Because of the early onset of the disease, screening of this group of women should start at an earlier age than in the general population. The association of breast magnetic resonance imaging (BMRI) and ultrasonography (US) with mammography (MX) and clinical breast examination (CBE) in the regular surveillance of these individuals has been proposed and seems to improve the early detection of breast cancer. Methods Within a multicenter study started by the Istituto Superiore di Sanita (Rome), at the Istituto Nazionale Tumori of Milan (INT) we enrolled 116 women at high genetic risk for breast cancer; they were either BRCA1 or BRCA2 mutation carriers or had a strong family history of breast cancer. They underwent CBE, MX, US and BMRI once a year. Results Between June 2000 and April 2005, at INT 12 cancers were detected among the 116 screened individuals (10%). In this subgroup, 1 patient refused BMRI and in 2 cases US was not performed. With BMRI we found 11 cancers and 6 of them were detectable only by this technique. In these 6 cases, the size of the disease was less than 1 cm and MX was false negative due to irregularly nodular parenchyma in 4 cases and scar tissue or prosthesis in the other 2. US was not performed in 2 cases and was false negative in 4 cases. Three false positive results were found with BMRI: 1 case was considered suspect but related to hormonal influences; 1 case with the same pattern was sent for second-look US, which gave a negative result and BMRI review after 6 months showed normalization of the parenchyma; in the third case histology revealed the presence of adenosis. No false positive results were registered for MX. Conclusions The aim of secondary prevention is the detection of cancer at its earliest stage. BMRI screening in women with BRCA1 or BRCA2 mutations or at high familiar risk appears to be highly sensitive and may detect mammographically occult disease. The accuracy of MR imaging is higher than that of conventional imaging but the technique is flawed by a lower specificity. In order to avoid unnecessary biopsies we believe that the combination of BMRI and conventional imaging can be very useful in screening women with a high genetic risk of breast cancer, especially with second-look evaluation by means of US when BMRI yields the only positive diagnostic result. Second-look US has been demonstrated to be of critical importance both in recognizing false positive BMRI results and in guiding biopsies, when necessary.

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Evaluation of a rapid dipstick test, Malar-CheckTM, for the diagnosis of Plasmodium falciparum malaria in Brazil

Revista do Instituto de Medicina Tropical de São Paulo ◽

10.1590/s0036-46652002000500012 ◽

2002 ◽

Vol 44 (5) ◽

pp. 293-296 ◽

Cited By ~ 9

Author(s):

Priscilla Elisangela AVILA ◽

Karin KIRCHGATTER ◽

Karen Cristina S. BRUNIALTI ◽

Alessandra M. OLIVEIRA ◽

Rinaldo F. SICILIANO ◽

...

Keyword(s):

Plasmodium Falciparum ◽

False Positive ◽

False Negative ◽

Plasmodium Falciparum Malaria ◽

Dipstick Test ◽

True Negative ◽

Disease Evolution ◽

Negative Results ◽

False Positive Test ◽

Positive Results

The present study was carried out to evaluate the Malar-CheckTM Pf test, an immunochromatographic assay that detects Plasmodium falciparum Histidine Rich Protein II, does not require equipment, and is easy and rapid to perform. In dilution assays performed to test sensitivity against known parasite density, Malar-CheckTMwere compared with thick blood smear (TBS), the gold standard for diagnosis. Palo Alto isolate or P. falciparum blood from patients with different parasitemias was used. The average cut-off points for each technique in three independent experiments were 12 and 71 parasites/mm³ (TBS and Malar-CheckTM, respectively). In the field assays, samples were collected from patients with fever who visited endemic regions. Compared to TBS, Malar-CheckTMyielded true-positive results in 38 patients, false-positive results in 3, true-negative results in 23, and false-negative result in 1. Malar-CheckTMperformed with samples from falciparum-infected patients after treatment showed persistence of antigen up to 30 days. Malar-CheckTM should aid the diagnosis of P. falciparum in remote areas and improve routine diagnosis even when microscopy is available. Previous P. falciparum infection, which can determine a false-positive test in cured individuals, should be considered. The prompt results obtained with the Malar-CheckTM for early diagnosis could avoid disease evolution to severe cases.

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Critical Evaluation of Impedance Phlebography for the Diagnosis of Deep Vein Thrombosis

Thrombosis and Haemostasis ◽

10.1055/s-0038-1649161 ◽

1974 ◽

Vol 31 (02) ◽

pp. 273-278

Author(s):

Kenneth K Wu ◽

John C Hoak ◽

Robert W Barnes ◽

Stuart L Frankel

Keyword(s):

Deep Vein Thrombosis ◽

False Positive ◽

False Negative ◽

Critical Evaluation ◽

Original Method ◽

Vein Thrombosis ◽

Negative Results ◽

False Negative Results ◽

Deep Vein ◽

Positive Results

SummaryIn order to evaluate its daily variability and reliability, impedance phlebography was performed daily or on alternate days on 61 patients with deep vein thrombosis, of whom 47 also had 125I-fibrinogen uptake tests and 22 had radiographic venography. The results showed that impedance phlebography was highly variable and poorly reliable. False positive results were noted in 8 limbs (18%) and false negative results in 3 limbs (7%). Despite its being simple, rapid and noninvasive, its clinical usefulness is doubtful when performed according to the original method.

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Factors Associated With PSA False Negative and False Positive Results and the Impact on Patient's Health: A Cohort Study

Case Medical Research ◽

10.31525/ct1-nct03978299 ◽

2019 ◽

Author(s):

Keyword(s):

Cohort Study ◽

False Positive ◽

False Negative ◽

Factors Associated ◽

The Impact ◽

Positive Results

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Evaluation of Positive T- and B-Cell Gene Rearrangement Studies Among Patients Without a Definitive Diagnosis by Other Assays

American Journal of Clinical Pathology ◽

10.1093/ajcp/aqz112.067 ◽

2019 ◽

Vol 152 (Supplement_1) ◽

pp. S35-S36

Author(s):

Hadrian Mendoza ◽

Christopher Tormey ◽

Alexa Siddon

Keyword(s):

T Cell ◽

False Positive ◽

Gene Rearrangement ◽

Hematologic Malignancy ◽

False Negative ◽

False Positives ◽

False Negatives ◽

True Negative ◽

Flow Cytometric ◽

Pathology Reports

Abstract In the evaluation of bone marrow (BM) and peripheral blood (PB) for hematologic malignancy, positive immunoglobulin heavy chain (IG) or T-cell receptor (TCR) gene rearrangement results may be detected despite unrevealing results from morphologic, flow cytometric, immunohistochemical (IHC), and/or cytogenetic studies. The significance of positive rearrangement studies in the context of otherwise normal ancillary findings is unknown, and as such, we hypothesized that gene rearrangement studies may be predictive of an emerging B- or T-cell clone in the absence of other abnormal laboratory tests. Data from all patients who underwent IG or TCR gene rearrangement testing at the authors’ affiliated VA hospital between January 1, 2013, and July 6, 2018, were extracted from the electronic medical record. Date of testing; specimen source; and morphologic, flow cytometric, IHC, and cytogenetic characterization of the tissue source were recorded from pathology reports. Gene rearrangement results were categorized as true positive, false positive, false negative, or true negative. Lastly, patient records were reviewed for subsequent diagnosis of hematologic malignancy in patients with positive gene rearrangement results with negative ancillary testing. A total of 136 patients, who had 203 gene rearrangement studies (50 PB and 153 BM), were analyzed. In TCR studies, there were 2 false positives and 1 false negative in 47 PB assays, as well as 7 false positives and 1 false negative in 54 BM assays. Regarding IG studies, 3 false positives and 12 false negatives in 99 BM studies were identified. Sensitivity and specificity, respectively, were calculated for PB TCR studies (94% and 93%), BM IG studies (71% and 95%), and BM TCR studies (92% and 83%). Analysis of PB IG gene rearrangement studies was not performed due to the small number of tests (3; all true negative). None of the 12 patients with false-positive IG/TCR gene rearrangement studies later developed a lymphoproliferative disorder, although 2 patients were later diagnosed with acute myeloid leukemia. Of the 14 false negatives, 10 (71%) were related to a diagnosis of plasma cell neoplasms. Results from the present study suggest that positive IG/TCR gene rearrangement studies are not predictive of lymphoproliferative disorders in the context of otherwise negative BM or PB findings. As such, when faced with equivocal pathology reports, clinicians can be practically advised that isolated positive IG/TCR gene rearrangement results may not indicate the need for closer surveillance.

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Three Years of Experience With Random Urinary Homovanillic and Vanillylmandelic Acid Levels in the Diagnosis of Neuroblastoma

PEDIATRICS ◽

10.1542/peds.79.2.203 ◽

1987 ◽

Vol 79 (2) ◽

pp. 203-205

Author(s):

Mendel Tuchman ◽

Margaret L. R. Ramnaraine ◽

William G. Woods ◽

William Krivit

Keyword(s):

False Positive ◽

Homovanillic Acid ◽

False Negative ◽

False Negative Rate ◽

Urine Samples ◽

Vanillylmandelic Acid ◽

Test Results ◽

Upper Limit ◽

Positive Results ◽

Rule Out

During the last 3 years, random urine samples from 408 patients were tested for elevated homovanillic acid (HVA) and vanillylmandelic acid (VMA) levels to rule out the diagnosis of neuroblastoma. Thirty-seven of these patients had elevated HVA and/or VMA levels, and neuroblastoma was subsequently diagnosed. In three additional patients with negative test results (normal HVA and VMA levels), tumors were subsequently diagnosed (false-negative rate of 7.5%). Ten percent of the patients with neuroblastoma had normal HVA and 27.5% had normal VMA levels at the time of diagnosis. Only one patient (2.5%) with neuroblastoma had elevated VMA levels in the presence of normal HVA levels. More than 60% of the patients with neuroblastoma had urinary HVA and/or VMA levels higher than twice the upper limit of normal. No false-positive results were encountered. Age and stage distributions of the patients are shown, and the significance of the results is discussed.

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N.B.T. TEST—FALSE-NEGATIVE AND FALSE-POSITIVE RESULTS

The Lancet ◽

10.1016/s0140-6736(72)91072-0 ◽

1972 ◽

Vol 299 (7764) ◽

pp. 1341-1342 ◽

Cited By ~ 23

Author(s):

RonaldP. Ng ◽

T.K. Chan ◽

D. Todd

Keyword(s):

False Positive ◽

False Negative ◽

Positive Results

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Ultrasonographicpotencial in detection of Acute Appendicitis

Bulletin of Siberian Medicine ◽

10.20538/1682-0363-2009-4-140-147 ◽

2009 ◽

Vol 8 (4) ◽

pp. 140-147

Author(s):

V. N. Piskunov ◽

V. D. Zavadovskaya ◽

N. G. Zavyalova

Keyword(s):

Acute Appendicitis ◽

False Negative ◽

Power Doppler ◽

Vermiform Appendix ◽

Vascular Pattern ◽

True Negative ◽

Horizontal Section ◽

Negative Results ◽

Interior Wall ◽

Positive Results

On the grounds of ultrasonography of 275 patients with suspected Acute Appendicitis (AA) the diagnosis was confirmed in 63 (22,9%) cases, it was true-positive results; in 3 (1,1%) cases of non-confirmed AA ultrasound findings were regarded as false-positive results. True-negative results of examination were obtained in 194 cases (70,5%) and false-negative results — in 15 cases (5,5%). The presence of rarevascularity of interior wall and clear visualization of vessels in mesentery of vermiform appendix is typical for congestive appendicitis. When phlegmonous appendicitis there are numerous vascular branches in interior wall blood stream of appendix: they make a picture of color «crown» in horizontal section and color «stripe» in longitudinal section. Gangrenous appendicitis is attached to few color spots in those parts of appendix wall which are not destroyed yet. Vascular pattern in adjacent intestinal loops predominates over vascular pattern of vermiform appendix. In case of empyema vermiform appendix vascular pattern in the wall is detected only in mesentery area. Vascular pattern of appendix is not detected in cases of appendicular infiltrate and periappendicular abscess unlike vascular pattern of adjacent intestinal loops which is rather intensified. The sensitivity of ultrasonography in AA detection was 80,7%, specificity — 98,4%, and accuracy — 93,4%. High index of diagnostic effectiveness of the method was obtained because of adoption of combining B-mode with both Colour Doppler and Power Doppler methods.

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Thyroid Screening for Early Discharged Infants

PEDIATRICS ◽

10.1542/peds.98.1.41 ◽

1996 ◽

Vol 98 (1) ◽

pp. 41-44

Author(s):

Judy G. Saslow ◽

Ernest M. Post ◽

Carol A. Southard

Keyword(s):

New Jersey ◽

Congenital Hypothyroidism ◽

False Positive ◽

False Negative ◽

Negative Results ◽

Thyroid Screening ◽

False Negative Results ◽

Positive Results

Objective. As neonatal discharge before 24 hours of life becomes commonplace, the rejection of congenital hypothyroidism (CH) screening specimens obtained too early has created the need for numerous additional tests. We sought to determine whether the specimens obtained before 24 hours could be used safely. Methods. During a 31-day period we measured thyrotropin in all thyroid-screening specimens that had been obtained before 24 hours. We also examined the early specimens from every infant diagnosed in New Jersey with CH during 1993 or 1994. Results. Among the 663 specimens, those obtained at or before 12 hours and those from infants with birth weights less than 2500 g had too many low thyroxine results to be useful. Among the 515 specimens obtained at more than 12 to 24 hours from newborns weighing 2500 g or more, 37 (7%) had low thyroxine levels and 12 (2.3%) had thyrotropin levels of 20 µIU/mL (mU/L) or higher. Four hundred seventy-one of the 515 infants had subsequent specimens obtained at more than 24 hours, and none of the results were abnormal. There was no child weighing more than or equal to 2500 g who was diagnosed with CH in 1993 and 1994 whose specimen obtained at 24 hours or less was normal. Conclusions. Accepting specimens obtained at more than 12 to 24 hours from infants weighing 2500 g or more would have resulted in more than the usual number of false-positive results but no false-negative results. This would have decreased the requests for additional specimens by more than 90%.

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