Betacoronavirus ; Clinical Laboratory Techniques ; Coronavirus Infections ; diagnosis ; False Negative Reactions ; Humans ; Nucleic Acid Amplification Techniques ; Pandemics ; Pneumonia, Viral ; diagnosis

PURPOSE: Sentinel lymph node (SLN) biopsy (SLNB) is widely performed for axillary staging in patients with breast cancer. Based on the results of frozen section examination (FSE), surgeons can decide to continue further axillary dissections. This study aimed to verify the accuracy of FSE for SLNs. METHODS: We reviewed the records of 4,219 patients who underwent SLNB for primary invasive breast cancer between 2007 and 2016 at the Severance Hospital. We evaluated factors associated with the false-negative results of FSE for SLNs using the Generalized Estimating Equations model. RESULTS: A total of 1,397 SLNs from 908 patients were confirmed to be metastatic. Seventy-one patients (1.7%) had confirmed pathologic N2 or N3 stage. Among metastatic SLNs, micrometastasis was found in 234 (16.8%). The overall accuracy of SLNB was 98.5%. The sensitivity and false-negative rate of FSE were 86.4% and 13.6%, respectively. Several clinicopathological factors, including the size of SLN metastases, suspicious preoperative axillary lymph nodes, and luminal B subtype, were associated with a higher rate of false-negative results. CONCLUSION: Most patients were not indicated for axillary lymph node dissection. Some patients may show transition in their permanent pathology due to the size of the metastatic node. However, the false-negative results of FSE for SLNs based on the size of the metastatic node did not change our practice. Therefore, intraoperative FSE for SLN should not be routinely performed for all breast cancer patients.
Biopsy ; Breast Neoplasms ; Breast ; False Negative Reactions ; Frozen Sections ; Humans ; Lymph Node Excision ; Lymph Nodes ; Neoplasm Metastasis ; Neoplasm Micrometastasis ; Pathology ; Phenobarbital ; Sentinel Lymph Node Biopsy ; Surgeons

PURPOSE: We investigated factors predictive of false-negative pulmonary lesions with nonspecific benign cytology results on percutaneous transthoracic fine-needle aspiration biopsy (FNAB). MATERIALS AND METHODS: We included 222 pulmonary lesions that had a nonspecific benign result from percutaneous transthoracic FNAB between March 2005 and December 2012, and were confirmed by subsequent pathologic results or adequate clinical follow up over at least 2 years. Clinical, imaging, and biopsy procedure-related findings were compared between lesions with a final diagnosis of malignancy (false-negative) and lesions with a benign diagnosis (true-negative). Multivariate logistic regression analysis was performed to identify significant predictors of false-negatives. RESULTS: Of 222 lesions, 115 lesions were proved to be false-negatives, and 107 were true-negatives. Compared with the true-negatives, false-negative lesions showed significantly older age (p=0.037), higher maximum standardized uptake value (SUVmax) on positron emission tomography (p=0.001), larger lesion size (p=0.007), and lesion characteristics of a subsolid nodule (p=0.007). On multivariate logistic regression analysis, SUVmax, lesion size, and lesion characteristics were significant predictors of false-negative results. CONCLUSION: Among the clinical, radiologic, and procedure-related factors analyzed, high SUVmax, large lesion size, and subsolid lesions were useful for predicting malignancy in pulmonary lesions with nonspecific benign cytology results on FNAB.
Adult ; Biopsy, Fine-Needle/*methods ; Cohort Studies ; Cytodiagnosis ; False Negative Reactions ; Female ; Humans ; Lung/pathology ; Lung Diseases/*diagnosis/pathology ; Male ; Middle Aged ; Retrospective Studies

OBJECTIVE: To retrospectively evaluate the features of undiagnosed breast cancers on prior screening breast magnetic resonance (MR) images in patients who were subsequently diagnosed with breast cancer, as well as the potential utility of MR-computer-aided evaluation (CAE). MATERIALS AND METHODS: Between March 2004 and May 2013, of the 72 consecutive pairs of prior negative MR images and subsequent MR images with diagnosed cancers (median interval, 32.8 months; range, 5.4-104.6 months), 36 (50%) had visible findings (mean size, 1.0 cm; range, 0.3-5.2 cm). The visible findings were divided into either actionable or underthreshold groups by the blinded review by 5 radiologists. MR imaging features, reasons for missed cancer, and MR-CAE features according to actionability were evaluated. RESULTS: Of the 36 visible findings on prior MR images, 33.3% (12 of 36) of the lesions were determined to be actionable and 66.7% (24 of 36) were underthreshold; 85.7% (6 of 7) of masses and 31.6% (6 of 19) of non-mass enhancements were classified as actionable lesions. Mimicking physiologic enhancements (27.8%, 10 of 36) and small lesion size (27.8%, 10 of 36) were the most common reasons for missed cancer. Actionable findings tended to show more washout or plateau kinetic patterns on MR-CAE than underthreshold findings, as the 100% of actionable findings and 46.7% of underthreshold findings showed washout or plateau (p = 0.008). CONCLUSION: MR-CAE has the potential for reducing the number of undiagnosed breast cancers on screening breast MR images, the majority of which are caused by mimicking physiologic enhancements or small lesion size.
Adult ; Aged ; Breast/*pathology ; Breast Neoplasms/*diagnosis/pathology/radiography ; Diagnosis, Computer-Assisted/*methods ; False Negative Reactions ; Female ; Humans ; Magnetic Resonance Imaging/*methods ; Mammography/*methods ; Middle Aged ; Retrospective Studies

BACKGROUND/AIMS: To evaluate a new monoclonal antibody for Helicobacter pylori urease in gastric tissue. METHODS: A total of 107 volunteers were enrolled. All subjects underwent a 13C-urea breath test and esophagogastroduodenoscopy. Gastric aspirates were analyzed for pH and ammonia. Six biopsy specimens in the gastric antrum and body were obtained for a rapid urease test and histology. The new monoclonal antibody-based H. pylori urease test (HPU) was performed to rapidly and qualitatively detect urease in two biopsy specimens. RESULTS: H. pylori infection was diagnosed in 73 subjects. The sensitivity and specificity of the HPU was 89% and 74%, respectively. The subjects were divided into two groups: one with true-positive and true-negative HPU results (n = 90) and the other with false-positive and false-negative HPU results (n = 17). Across all subjects, ammonia levels were 900.5 +/- 646.7 and 604.3 +/- 594.3 mumol/L (p > 0.05), and pH was 3.37 +/- 1.64 and 2.82 +/- 1.51 (p > 0.05). Sensitivity was higher in the presence of atrophic gastritis or intestinal metaplasia. CONCLUSIONS: HPU detected H. pylori in approximately 10 min. Gastric aspirate ammonia and pH levels did not affect the test results. Sensitivity was good in the presence of atrophic gastritis or intestinal metaplasia.
Adult ; Antibodies, Monoclonal/*immunology ; Bacterial Proteins/*analysis/immunology ; Biomarkers/analysis ; Biopsy ; False Negative Reactions ; False Positive Reactions ; Female ; Gastritis, Atrophic/*diagnosis/microbiology ; Helicobacter Infections/*diagnosis/microbiology ; Helicobacter pylori/*enzymology/immunology ; Humans ; *Immunologic Tests ; Male ; Metaplasia ; Middle Aged ; Predictive Value of Tests ; Pyloric Antrum/*microbiology/pathology ; Reproducibility of Results ; Time Factors ; Urease/*analysis/immunology ; Workflow

OBJECTIVE: To analyze the false-negative proportion and reasons of positioning test in benign paroxysmal positional vertigo (BPPV). METHOD: Sixty-eight cases were reviewed and analyzed during February to April 2009. All patients had typical clinical history of BPPV and diagnosed by positioning test,and all were treated with PRM successfully. If positioning test at the first time were negative, examinations repeated after either head shaking or return visits. RESULT: Thirteen patients (19.12%) appeared false-negative in positoning test, and 11 cases showed typical nystagmus after head shaking,while 2 cases were diagnosed by return visitis the next day. There were no statistically difference between false-negative group and positive group in age (P > 0.05), gender (P > 0.05), course of disease (P > 0.05) and types of semi-circular canal (P > 0.05). CONCLUSION Re-examinations after head shaking or return visits are useful for the diagnosis in the suspected BPPV patients who have negative positioning test.
Benign Paroxysmal Positional Vertigo ; diagnosis ; therapy ; False Negative Reactions ; Humans ; Patient Positioning

OBJECTIVE: To evaluate the diagnostic outcomes of ultrasonography-guided core needle biopsy (US-CNB), US-guided vacuum-assisted biopsy (US-VAB), and stereotactic-guided vacuum-assisted biopsy (S-VAB) for diagnosing suspicious breast microcalcification. MATERIALS AND METHODS: We retrospectively reviewed 336 cases of suspicious breast microcalcification in patients who subsequently underwent image-guided biopsy. US-CNB was performed for US-visible microcalcifications associated with a mass (n = 28), US-VAB for US-visible microcalcifications without an associated mass (n = 59), and S-VAB for mammogram-only visible lesions (n = 249). Mammographic findings, biopsy failure rate, false-negative rate, and underestimation rate were analyzed. Histological diagnoses and the Breast Imaging Reporting and Data System (BI-RADS) categories were reported. RESULTS: Biopsy failure rates for US-CNB, US-VAB, and S-VAB were 7.1% (2/28), 0% (0/59), and 2.8% (7/249), respectively. Three false-negative cases were detected for US-CNB and two for S-VAB. The rates of biopsy-diagnosed ductal carcinoma in situ that were upgraded to invasive cancer at surgery were 41.7% (5/12), 12.9% (4/31), and 8.6% (3/35) for US-CNB, US-VAB, and S-VAB, respectively. Sonographically visible lesions were more likely to be malignant (66.2% [51/77] vs. 23.2% [46/198]; p < 0.001) or of higher BI-RADS category (61.0% [47/77] vs. 22.2% [44/198]; p < 0.001) than sonographically invisible lesions. CONCLUSION: Ultrasonography-guided vacuum-assisted biopsy is more accurate than US-CNB when suspicious microcalcifications are detected on US. Calcifications with malignant pathology are significantly more visible on US than benign lesions.
Adult ; Aged ; Biopsy, Large-Core Needle ; Breast/*pathology ; Breast Neoplasms/*pathology/ultrasonography ; Carcinoma, Intraductal, Noninfiltrating/pathology ; False Negative Reactions ; Female ; Humans ; Image-Guided Biopsy ; Imaging, Three-Dimensional ; Middle Aged ; Retrospective Studies ; Ultrasonography, Mammary

PURPOSE: Ultrasound (US) and US-guided fine needle aspiration biopsies (FNAB) are considered the modalities of choice for assessing lymph nodes suspected of containing metastases, but the sensitivity of FNAB varies and is specific to the operator. We analyzed the risk of FNAB providing false negative results of lateral neck node metastasis, and evaluated diagnostic accuracy of FNAB, in patients with papillary thyroid cancer. MATERIALS AND METHODS: FNAB was performed in 242 patients suspected of having lateral neck node metastasis on preoperative imaging. Thyroglobulin in the fine-needle aspirate washout (FNA wash-out Tg) and computed tomography enhancement (Hounsfield units) were measured. Patients with negative results on FNAB were examined by intraoperative frozen section. The false negative and true negative groups were compared. RESULTS: Of the 242 patients, 130 were confirmed as having lateral neck node metastases. In 74 patients, the metastasis was identified by FNAB. False positive results were observed in 2 patients (0.8%) and false negatives in 58 (44.6%). Risk analysis showed that patient age <45 years (p=0.006), tumor size >1 cm (p=0.008) and elevated FNA wash-out Tg (p=0.004) were significantly associated with false negative results on FNAB. The accuracy of FNAB increased significantly when combined with FNA wash-out Tg (p=0.003). CONCLUSION: To reduce the false negative rate of FNAB, patient age (<45 years), tumor size (>1 cm) and FNA wash-out Tg (>34.8 ng/mL) should be considered in preoperative planning. Accuracy may be improved by combining the results of FNAB and FNA wash-out Tg.
Adolescent ; Adult ; Aged ; Biopsy, Fine-Needle ; Carcinoma/*diagnosis/*pathology/radiography/surgery ; False Negative Reactions ; Female ; Humans ; Lymph Nodes/*pathology/radiography ; Lymphatic Metastasis/*pathology/radiography ; Male ; Middle Aged ; Multivariate Analysis ; Preoperative Care ; Risk Factors ; Sensitivity and Specificity ; Thyroglobulin/metabolism ; Thyroid Gland/*pathology ; Thyroid Neoplasms/*diagnosis/*pathology/radiography/surgery ; Tomography, X-Ray Computed ; Young Adult

The primary objectives of this retrospective study were to determine the cancer detection rate of PET/CT in this institution and to compare the sensitivity and specificity of low-dose PET/CT to that of PET with high-dose CT. Three hundred sixty-seven (367) patients with unremarkable history, family history of cancer, symptoms or abnormal diagnostic tests, and with follow-up studies were included. PET/CT and histopathology results were noted. Individual and overall cancer detection rates, as well as sensitivities and specificities for each subgroup, were computed. Overall cancer detection rates was 22.3%, for low-dose PET/CT was 17.9%, and for high-dose PET/CT was 24.4%. Using the chi squared test of independence, no statistically significant difference was found between the calculated sensitivities and specificities of low- and high-dose PET/CT across all patient groups. Using the Mantel-Haeaszel chi squared test, a statistically significant association between the subindication for malignancy screening and PET/CT results was established with subindications pointing to a higher suspicion for malignancy having a higher probability of detecting a malignancy. Therefore, high-dose PET/CT as a screening test would be advised for high-risk patients and low-dose PET/CT would be recommended because of its similar accuracy but lower radiation exposure.

Human ; Male ; Female ; Aged 80 and over ; Aged ; Middle Aged ; Adult ; Young Adult ; Adolescent ; Child ; Positron-Emission Tomography ; Tomography Scanners, X-Ray Computed ; neoplasms-diagnosis ; False Positive Reactions ; False Negative Reactions

BACKGROUND/AIMS: To investigate the rate of detection of monosodium urate (MSU) crystals in the synovial fluid (SF) of patients with acute gouty arthritis and factors associated with false-negative results. METHODS: A total of 179 patients with acute gouty arthritis who had undergone SF crystal examination were identified from the data warehouse of two university hospitals. Clinical and laboratory data were obtained from the medical records. RESULTS: The overall rate of detection of MSU crystals was 78.8%. In univariate analyses, the only significant differences between the variables of crystal-negative and crystal-positive patients were a lower C-reactive protein level (p = 0.040) and fewer patients undergoing emergent surgery in the crystal-positive group (p = 4.5 x 10(-6)). In logistic regression analyses, MSU crystal-negative results were significantly associated with the interval from arthritis onset to crystal examination (p = 0.042), and this was the most significant risk factor for arthroscopic surgery (p = 2.1 x 10(-4)). Seventeen patients who underwent arthroscopic surgery had a significantly longer hospital stay (p = 0.007) and a significant delay in gout treatment (p = 8.74 x 10(-5)). The distribution of crystal-negative patients differed significantly between the SF samples that were evaluated by both the laboratory medicine and the rheumatology departments (p = 1.2 x 10(-14)), and the kappa value was 0.108. CONCLUSIONS: Although several clinical features were associated with detection failure, SF MSU crystal identification was critically dependent on the observer. Considering the impact on the treatment outcomes, implementation of a quality control program is essential.
Acute Disease ; Aged ; Arthritis, Gouty/diagnosis/*metabolism/*surgery ; Arthroscopy ; Biological Markers/metabolism ; Crystallization ; False Negative Reactions ; Female ; Hospitals, University ; Humans ; Length of Stay ; Logistic Models ; Male ; Microscopy, Polarization ; Middle Aged ; Observer Variation ; Predictive Value of Tests ; Reproducibility of Results ; Republic of Korea ; Retrospective Studies ; Synovial Fluid/*metabolism ; Time Factors ; Time-to-Treatment ; Treatment Outcome ; Uric Acid/*metabolism