Diagnostic Precision (diagnostic + precision)

Distribution by Scientific Domains

Selected Abstracts

Efficacy of fine-needle aspiration biopsy in diagnosis of breast cancer: A retrospective study of 303 cases in Bahrain

F.R.C.Path, Khalid Al-Sindi M.D.
Abstract Breast cancer is a leading cause of death in many countries worldwide and breast lesions remain a common diagnostic dilemma. Fine-needle aspiration biopsy (FNAB) has been suggested as the most important, first line, minimally invasive measure in the management of patients with breast lesions. The aim of this study is to evaluate the efficacy of FNAB in patients with breast lesions by comparing the diagnostic accuracy of cytology results with that of the definitive histological examination outcome and also to investigate the added value of a single aspirator experience to the overall diagnostic precision and compared with the internationally published results. A retrospective study of 303 breast FNAB samples were carried out by a single experienced cytopathologist with complete comparison records. The prevalence of positive cytologic diagnosis for the breast cancer was determined to be 20.4%. The overall diagnostic accuracy of FNAB was 97.9%, with a specificity and sensitivity of 98.3 and 96.5%, respectively. The overall positive and negative predictive values were determined to be 93.2 and 99.2%, respectively. In addition, the sensitivity was comparable in cases that have been attempted by palpation-guided sampling compared with those aspirations that were carried out under US guidance. Results from this study confirm that FNAB biopsies performed and reported by a dedicated, single, skilled cytopathologist are highly effective in diagnosis of breast lesions and reliable in differentiating benign and malignant breast lesions with an overall high efficacy in a specialized laboratory-based FNAB clinic. Diagn. Cytopathol. 2009. 2009 Wiley-Liss, Inc. [source]

Flow cytometric analysis of cell-surface and intracellular antigens in the diagnosis of acute leukemia

Rogelio Paredes-Aguilera
Abstract To evaluate the usefulness of flow cytometric detection of intracellular antigens (Ags) in establishing proper lineage affiliation and its contribution to the diagnosis of acute leukemia, we studied 100 consecutive patients in whom acute leukemia was diagnosed between January 1997 and July 1998. Immunological classification was assessed using a three-line panel of monoclonal antibodies for phenotypic characterization of leukemic blast cells as proposed at the First Latin American Consensus Conference for Flow Cytometric Immunophenotyping of Leukemia. We found 74 cases of B-cell lineage acute lymphoblastic leukemia (ALL), seven cases of T-cell ALL, and 19 cases of acute myeloid leukemia (AML). In this study cytoplasmic (cy) CD79a, cyCD22, cyCD3, and cyMPO were highly sensitive, specific B, T, and myeloid markers that were expressed in virtually all cases of B and T cell ALL and in all subtypes of AML. Applied in combination with immunophenotyping this knowledge led to improvement in diagnostic precision and refinement of immunological classification, ensuring the selection of the most appropriate therapy for the patients studied. In conclusion, intracellular Ags detection was of utmost importance in establishing correct lineage affiliation in cases lacking expression of B, T, or myeloid surface Ags or disclosing equivocal or ambiguous immunophenotypic features and in identifying biphenotypic acute leukemia. In combination with FAB morphology and immunophenotyping, we were able to reliably classify all patients with acute leukemia in this study. Am. J. Hematol. 68:69,74, 2001. 2001 Wiley-Liss, Inc. [source]

Task Specificity in Adductor Spasmodic Dysphonia Versus Muscle Tension Dysphonia

Nelson Roy PhD
Abstract Objectives: Adductor spasmodic dysphonia (ADSD) has been characterized as a "task specific" laryngeal dystonia, meaning that the severity of dysphonia varies depending on the demands of the vocal task. Voice produced in connected speech as compared with sustained vowels is said to provoke more frequent and severe laryngeal spasms. This study examined the diagnostic value of "task specificity" as a marker of ADSD and its potential to differentiate ADSD from muscle tension dysphonia (MTD), a functional voice disorder that can often masquerade as ADSD. Study Design: Case-control study. Methods: Five listeners, blinded to the purpose of the study, used a 10 cm visual analogue scale to rate dysphonia severity of subjects with ADSD (n = 36) and MTD (n = 45) producing either connected speech or a sustained vowel "ah." Results: In ADSD, dysphonia severity for connected speech (M = 6.22 cm, SD = 2.56) was rated significantly more severe than sustained vowel productions (M = 4.8 cm, SD = 2.8 [t (35) = 3.67, P < .001]). In MTD, however, no significant difference in severity was observed for the connected speech sample (M = 5.98 cm, SD = 2.83 versus the sustained vowel M = 5.86 cm, SD = 2.87 [t (44) = 0.378, P = .707]). The receiver operating characteristic (ROC) curve, an index of the accuracy of task specificity as a diagnostic marker, revealed that a 1 cm difference criterion correctly identified 53% of ADSD cases (sensitivity) and 76% of MTD cases (specificity) (,2 (1) = 6.88, P = .0087). Conclusions: Reduced dysphonia severity during sustained vowels supports task specificity in ADSD but not MTD and highlights a valuable diagnostic marker whose recognition should contribute to improved diagnostic precision. [source]

Sentinel lymph nodes in malignant melanoma

CANCER, Issue 8 2004
Extended histopathologic evaluation improves diagnostic precision
Abstract BACKGROUND The optimal technique for sentinel lymph node (SN) assessment in patients with melanoma is controversial. Molecular analysis (reverse transcriptase,polymerase chain reaction) detects significantly greater numbers of SNs with suspected micrometastases (up to 71%) than does routine histopathology (approximately 20%). The authors sought to identify possible reasons for this discrepancy and to determine whether using an extended histopathologic protocol could improve diagnostic precision. METHODS Two hundred thirty-one SNs from 100 consecutive patients with cutaneous melanomas that measured 1,4 mm in thickness were bisected, and half of the lymph node was examined according to an extensive histopathologic protocol involving serial sectioning and immunohistochemical analysis of 3 melanocyte-associated markers (S-100, HMB-45, and Melan-A). RESULTS Lymph node melanocytic lesions were frequent, with micrometastases and benign nevus inclusions (BNI) found in SNs in 28% and 28% of patients, respectively (4 SNs contained both). Melan-A was the most sensitive immunohistochemical marker and was positive in all BNI-positive SNs and 97% of micrometastasis-positive SNs. Although HMB-45 showed differential labeling in micrometastases compared with BNI (82% vs. 16%), immunohistochemistry could not distinguish between those lesions. Micrometastases were already identified on the first central level in 49% of positive SNs, whereas only 23% of SNs with BNI were diagnosed on the first level. CONCLUSIONS Extensive serial sectioning with immunohistochemical analysis substantially increased the histopathologic detection of micrometastases and BNI in melanoma SNs to a level approaching the level reported for molecular techniques. The large number of BNIs represents an important potential source of imprecision (false positivity) in SN assays based on nonmorphologic methods. Cancer 2004. 2004 American Cancer Society. [source]