Home About us Contact
|
Home About us Contact | ||
|
|
||
False-negative Result (false-negative + result)
Selected AbstractsNew method for the detection of intraperitoneal free air by sonography: Scissors maneuverJOURNAL OF CLINICAL ULTRASOUND, Issue 8 2004Okkes Ibrahim Karahan MD Abstract Purpose This study was conducted to investigate the diagnostic value of a new sonographic technique for the detection of intraabdominal free air. Methods Seventy-two patients with a suspected gastrointestinal tract perforation were included in the study and prospectively evaluated by sonography and abdominal and chest radiography for the detection of intraperitoneal free air. A new sonographic technique (the scissors maneuver) was used to detect intraperitoneal free air superficial to the liver; the maneuver consists of applying and then releasing slight pressure onto the abdominal wall with the caudal part of a parasagittaly oriented linear-array probe. The results of the imaging studies were correlated with surgical findings when possible. Results Sixteen patients had a surgically proven gastrointestinal tract perforation causing pneumoperitoneum. Sonography and radiography each showed pneumoperitoneum in 15 patients, with 1 false-negative result for each modality. The sensitivity and specificity values of sonography and radiography were identical; sensitivity was 94% and specificity was 100% for both imaging modalities. The scissors maneuver was positive in all patients with sonographically detected pneumoperitoneum. Conclusions Sonography is an effective tool in the diagnosis of pneumoperitoneum, with sensitivity and specificity equal to those of radiography. The scissors maneuver may be a useful adjunct for improving the diagnostic yield of sonography. © 2004 Wiley Periodicals, Inc. J Clin Ultrasound 32:381,385, 2004 [source] Functional Magnetic Resonance Imaging Using Iron Oxide Particles in Characterizing Head and Neck Adenopathy,THE LARYNGOSCOPE, Issue 9 2000Henry T. Hoffman MD Abstract Objectives In lymph nodes harboring metastases the reticuloendothelial system is replaced by tumor cells and does not concentrate iron particles. This study assesses the value of contrast magnetic resonance imaging (MRI) using ultrasmall superparamagnetic iron oxide particles (Combidex, Advanced Magnetics, Inc., Cambridge, MA) to characterize and stage neck nodes. Study Design Prospective analysis of neck imaging by Combidex MRI, with correlation from pathological assessment of resected lymph nodes. Methods Nine patients underwent MRI and subsequent bilateral neck dissections (three), unilateral neck dissections (five) or fine-needle aspiration (one). Each case was evaluated for the number, location, MRI characteristics, and pathological assessment of lymph nodes. Results Forty-nine separate nodal levels were evaluated with both Combidex MRI and pathological assessment. The presence of metastatic nodal involvement among 45 levels was correctly assessed by the Combidex MRI (three false-negative results, one false-positive result; sensitivity, 84%; specificity, 97%). Analysis was possible for 101 of the individual lymph nodes identified by MRI that could be correlated with individual nodes pathologically examined. Combidex MRI assessment was correct for 99 nodes (one-false positive result, one false-negative result; sensitivity, 95%, specificity, 99%). Standard MRI interpretation without Combidex identified that 12 of 18 nodes (67%) that were greater than or equal to 10 mm (greatest dimension) contained tumor, whereas 9 of 83 nodes (11%) that were less than 10 mm contained tumor. Conclusions Combidex MRI provides functional information to characterize lymph nodes in the clinical staging of squamous cell carcinoma of the head and neck. The inability of MRI to identify small lymph nodes restricts the usefulness of this technique. [source] THE IMPACT OF SYNOPTIC CYTOLOGY REPORTING ON FINE-NEEDLE ASPIRATION CYTOLOGY OF THYROID NODULESANZ JOURNAL OF SURGERY, Issue 11 2007Cyril J. L. Tsan Background: Fine-needle aspiration cytology (FNAC) is integral to the diagnosis and management of patients with thyroid nodules. We introduced synoptic cytology reporting for thyroid nodules in 2004. The aim of this study was to examine the effect of synoptic cytology reporting in our institution. Methods: A comparative study of two 2-year periods (1 August 2002 to 1 August 2004 and 2 August 2004 to 2 August 2006) before and after the introduction of synoptic reporting was conducted from a prospectively collected database of patients presented with thyroid nodules. The only change during these periods was the format of FNAC reporting. We used the same radiological practice and cytopathology service throughout the study period. All patients are still being followed up. Results: There were a total of 660 patients. Of these, 376 were operated and 284 non-operated. The female to male ratio was 7:1. Comparing the two periods, the overall FNAC sensitivities were 60% versus 79.1%; specificities, 83.7% versus 79.4%; accuracy, 76% versus 79.3%; false-positive result, 16.3% versus 20.6% and false-negative result, 40% versus 20.9%. The non-diagnostic rates were 7.4% versus 3.15%. FNAC prompted surgery in 66.7% versus 100% in carcinoma and 56.4% versus 73.6% in adenoma. A benign FNAC prompted surgery in 15% versus 19.8% of cases. There was no thyroid cancer detected in the current follow up. Conclusions: Synoptic cytology reporting has resulted in an overall improvement in all measures of the tests. It is a simple and effective tool to use. Synoptic cytology reporting is therefore recommended for all endocrine surgical units. [source] De novo renal cell carcinoma of native kidney in renal transplant recipientsCANCER, Issue 2 2005Yann Neuzillet M.D. Abstract BACKGROUND The 10-year risk of developing a solid malignancy is 20% for kidney transplant recipients. The goal of the current study was to investigate the epidemiology and the diagnostic and prognostic parameters associated with de novo malignancies of the native kidney among transplant recipients at the authors' institution (Department of Urology and Renal Transplantation, Hôpital Salvator, Marseille, France). METHODS The authors reexamined the follow-up of 933 consecutive transplant recipients at their institution between 1987 and 2003. Immunossupressive therapy was not modified in the event of malignant disease, nor was systematic radiologic monitoring of native kidneys performed. All de novo malignancies of the native kidney were included in the current analysis. RESULTS Among the 933 patients examined, a combined total of 12 malignancies of the native kidney were diagnosed in 11 individuals. For these 11 individuals, the average ages at transplantation and diagnosis were 42.5 and 49.1 years, respectively. Ten malignancies were discovered fortuitously, whereas two were symptomatic. Among the 10 renal echographies performed, there was 1 false-negative result. Tomodensitometry was performed in 11 cases and yielded no false-negative results. The average tumor size was 37 mm. Nephrectomy was performed in 10 cases, and biopsy was performed in 1. Among the 12 kidney malignancies encountered in the current study, there were 7 conventional cell carcinomas, 3 basophilic papillary carcinomas, and 2 chromophobic renal cell carcinomas. Half of all tumors were Furhman Grade 3 lesions, and pT1aN0M0 tumors (2003 TNM staging system) also accounted for half of all malignancies in the current cohort. Two affected transplant recipients died (one due to disease), and the remaining nine are alive without recurrence and with normal renal functioning (median follow-up, 39 months). CONCLUSIONS There appears to be an increased risk of malignancy of the native kidney in renal transplant recipients, with high-grade and papillary tumors being particularly common. Consequently, systematic radiologic follow-up of native kidneys must be performed for individuals who undergo kidney transplantation. Cancer 2005. © 2004 American Cancer Society. [source] Stereotactic vacuum-assisted breast biopsy in 2874 patientsCANCER, Issue 2 2004A multicenter study Abstract BACKGROUND Vacuum-assisted breast biopsy (VAB) can replace surgical biopsy for the diagnosis of breast carcinoma. The authors evaluated the accuracy and clinical utility of VAB in a multicenter setting using a strict quality assurance protocol. METHODS In the current study, VABs were performed successfully for 2874 patients at 5 sites. Benign lesions were verified by follow-up. Surgery was recommended for malignant and borderline lesions. VAB was performed on patients with lesions rated as highly suspicious (6%), intermediate to suspicious (85%), or probably benign (9%). Fifty-eight percent of the lesions were < 10 mm and 70% had microcalcifications. RESULTS The authors identified 7% of patients with invasive carcinomas, 15% with ductal carcinomas in situ (DCIS), 5% with atypical ductal hyperplasias (ADH), and 0.6% with lobular carcinomas in situ. The results of the VAB necessitated an upgrade of 24% of patients with ADH to DCIS or DCIS and invasive carcinoma. Twelve percent of patients with DCIS proved to have invasive carcinoma. Seventy-three percent of the patients had benign lesions. Only 1 false-negative result was encountered (negative predictive value, 99.95%). Minor side effects were reported to occur in 1.4% of patients and 0.1% of patients required a subsequent intervention. Scarring relevant for mammography was rare among patients (i.e., 0.3% of patients had relevant scarring). CONCLUSIONS Quality-assured VAB was found to be highly reliable. VAB effectively identified patients with benign lesions and assisted therapeutic decisions. Most important, only a single case of malignancy was missed. A close interdisciplinary approach assured optimal results. Cancer 2004;100:245,51. © 2003 American Cancer Society. [source] Novel biomarker of HTLV-1-associated disease: Specific appearance of antibody recognizing the receptor-binding site on HTLV-1 envelope proteinCANCER SCIENCE, Issue 10 2004Yasuko Sagara We previously showed that 71-kDa heat shock cognate protein (HSC70) functions as a cellular receptor for gp46 protein via the gp46,197 region, corresponding to Asp197 to Leu216 of human T-cell lymphotropic virus type 1 (HTLV-1), leading to cell-to-cell transmission of HTLV-1. We found that HSC70 protein was contained in goat serum and casein used as blocking agents in the usual ELISA method. Here, it was demonstrated that HSC70 contamination in the blocking agents causes a false-negative result in the detection of anti-gp46,197 antibody in serum samples from HTLV-1-infected individuals. By using ELISA without the blocking agents, we detected antibodies recognizing the HSC70-binding site of gp46, and the anti-gp46,197 antibody specifically appeared in sera from patients with HTLV-1-associated diseases. The frequency of serum anti-gp46,197 antibody-positive individuals was 98% and 100% among ATLL and HAM/TSP patients, respectively, but only 6% among asymptomatic HTLV-1-infected carriers (ACs). The antibody titer in ATLL and HAM/TSP patients was higher than that in ACs (P>0.002 for ATLL; P>0.0001 for HAM/ TSP). These findings suggest that appearance of the anti-gp46,197 antibody is a predictive marker for the onset of HTLV-1-associated disease. [source] Sentinel Lymph Node Biopsy in Cutaneous Squamous Cell Carcinoma: A Systematic Review of the English LiteratureDERMATOLOGIC SURGERY, Issue 11 2006AMY SIMON ROSS MD BACKGROUND Although most cutaneous squamous cell carcinoma (SCC) is curable by a variety of treatment modalities, a small subset of tumors recur, metastasize, and result in death. Although risk factors for metastasis have been described, there are little data available on appropriate workup and staging of patients with high-risk SCC. OBJECTIVE We reviewed reported cases and case series of SCC in which sentinel lymph node biopsy (SLNB) was performed to determine whether further research is warranted in developing SLNB as a staging tool for patients with high-risk SCC. METHODS The English medical literature was reviewed for reports of SLNB in patients with cutaneous SCC. Data from anogenital and nonanogenital cases were collected and analyzed separately. The percentage of cases with a positive sentinel lymph node (SLN) was calculated. False negative and nondetection rates were tabulated. Rates of local recurrence, nodal and distant metastasis, and disease-specific death were reported. RESULTS A total of 607 patients with anogenital SCC and 85 patients with nonanogenital SCC were included in the analysis. A SLN could not be identified in 3% of anogenital and 4% of nonanogenital cases. SLNB was positive in 24% of anogenital and 21% of nonanogenital patients. False-negative rates as determined by completion lymphadenectomy were 4% (8/213) and 5% (1/20), respectively. Most false-negative results were reported in studies from 2000 or earlier in which the combination of radioisotope and blue dye was not used in the SLN localization process. Complications were reported rarely and were limited to hematoma, seroma, cutaneous lymphatic fistula, wound infection, and dehiscence. CONCLUSIONS Owing to the lack of controlled studies, it is premature to draw conclusions regarding the utility of SLNB in SCC. The available data, however, suggest that SLNB accurately diagnoses subclinical lymph node metastasis with few false-negative results and low morbidity. Controlled studies are needed to demonstrate whether early detection of subclinical nodal metastasis will lead to improved disease-free or overall survival for patients with high-risk SCC. [source] The value of frozen section in intraoperative surgical management of thyroid follicular carcinoma,HEAD & NECK: JOURNAL FOR THE SCIENCES & SPECIALTIES OF THE HEAD AND NECK, Issue 7 2003Danijel Do, en MD Abstract Background. Preoperative and intraoperative diagnosis of follicular carcinoma (FC), resulting in one-stage surgical treatment of follicular thyroid tumors, is an important issue in thyroid surgery. Methods. In the 10-year period there were 4158 operations performed on thyroid gland. There were 1559 patients with follicular tumors, 70 (4.4%) of them having FC. We analyzed the groups of patients with FC determined on frozen section (FS) and permanent section (PS) according to duration of clinical symptoms, ultrasound (US) examination, tumor size, patient gender and age, intensity of invasion, localization, and multiple or solitary occurrence of tumor. Results. FC was diagnosed in 39 (55.7%) patients on frozen section (FS). Among the encapsulated (minimal invasion) carcinomas, the FS was accurate in 19 of 33 (57.6%) FC and in 5 of 15 (27.8%) Hürthle cell carcinomas (HCC); among extensively invasive carcinoma in 11 of 14 (78.6%) FC and in 4 of 5 (80.0%) HCC. FC was significantly more common in men (p < .001) and in the right lobe (p < .05). We did not find statistically significant differences concerning duration of symptoms, US examination, tumor size, patient age, and multiple or solitary occurrence of the tumor between the patients with FC diagnosed on FS and the patients with FC diagnosed on PS. Conclusions. The intraoperative diagnosis of FC is difficult. Although the percentage of false-negative results was relatively high (44.3%), there were no false-positive results. This means that the second operation was avoided in 55.7% of the patients, and no unnecessary thyroidectomies were performed. FS biopsy is an important method in surgery of follicular tumors. Improved technical support and the ability to analyze a greater number of slides will increase the accuracy of the method. © 2003 Wiley Periodicals, Inc. Head Neck 25: 521,528, 2003 [source] Renal sonography in the diagnosis of renal obstruction or hydronephrosis in patients with cervical cancerJOURNAL OF CLINICAL ULTRASOUND, Issue 7 2002Verna Vanderpuye MBCHB Abstract Purpose The aim of this prospective study was to evaluate the role of renal sonography and its use as an alternative to intravenous urography in detecting ureteral obstruction or hydronephrosis in patients with cervical cancer. Materials and Methods Patients with biopsy-confirmed carcinoma of the cervix who were referred to the radiotherapy center from February 6, 2001, through July 20, 2001, were enrolled in this trial. All patients had previously undergone clinical staging by physical examination and either intravenous urography or CT scanning as the standard tests for diagnosing ureteral obstruction or hydronephrosis. All patients underwent renal sonography as an alternative diagnostic tool for diagnosing ureteral obstruction or hydronephrosis. Results Forty patients were enrolled. Their mean age was 46 years (range, 26,65 years). According to the FIGO staging system, 12% of the patients had clinical stages 1B2 and 2A disease, 20% had stage 2B, 8% had stage 3A, 50% had stage 3B, and 10% had a postoperative recurrence of cervical cancer. Thirty-four patients had had intravenous urography and 6 had had CT scans of the abdomen and pelvis. Sensitivity, specificity, positive and negative predictive values and overall accuracy rates for renal sonography were 76.5% (13/17), 100% (23/23), 100% (13/13), 85% (23/27), and 90% (36/40), respectively. Seventy-five percent (3/4) of the false-negative results occurred in patients with pelvic sidewall thickening on physical examination. Conclusions Renal sonography may be used as an effective and relatively low-cost means of diagnosing ureteral obstruction in patients with cervical cancer without clinically evident pelvic sidewall thickening. © 2002 Wiley Periodicals, Inc. J Clin Ultrasound 30:424,427, 2002 [source] Performance of the Now Malaria rapid diagnostic test with returned travellers: a 2-year retrospective study in a French teaching hospitalCLINICAL MICROBIOLOGY AND INFECTION, Issue 11 2005F. Durand Abstract Malaria caused by Plasmodium falciparum remains the major life-threatening parasitic infection in the world. The number of cases in non-endemic countries continues to increase, and it is important that misdiagnosis of malaria should not occur, especially in non-immune travellers, because of the high risk of a fatal outcome. In a retrospective study of 399 sera, the Now Malaria rapid test was compared with the quantitative buffy coat (QBC) test and microbiological examination of thin blood films. Compared with the QBC test and thin blood films, the Now Malaria test had sensitivity and specificity values of 96.4% and 97%, respectively, for the detection of pure P. falciparum infection. A negative predictive value of 99.4% allows this test to be included in diagnostic strategies for patients presenting with clinical suspicion of malaria. Two false-negative results were associated with low levels of parasitaemia in the specimens. Thus, use of the Now Malaria test alone to detect P. falciparum infection in non-endemic countries could lead to misdiagnosis of malaria. This rapid diagnostic test should therefore be performed in association with another prompt traditional method such as examination of thin blood films. [source] | ||||||||||||||||||||||