ABSTRACT
Twenty-eight laboratories evaluated a new fluorescence in situ hybridization (FISH) strategy for chronic myeloid leukemia. In a three-part study, bcr/abl1 D-FISH probes were used to study bone marrow specimens. First, laboratories familiarized themselves with the strategy by applying it to known normal and abnormal specimens. Then, collectively the laboratories studied 20 normal and 20 abnormal specimens blindly and measured workload. Finally, each laboratory and two experts studied six serial dilutions with 98-0% abnormal nuclei. Using the reported normal cutoff of < 1% abnormal nuclei, participants reported no false-negative cases and 15 false-positive cases (1-6.6% abnormal nuclei). Results provided by participants for serial dilutions approximated the expected percentages of abnormal nuclei, but those from the experts exhibited greater precision. The clinical sensitivity, precision, nomenclature, workload, recommendations for training, and quality assurance in methods using D-FISH in clinical practice are discussed.
Subject(s)
Clinical Laboratory Techniques/standards , Fusion Proteins, bcr-abl/genetics , In Situ Hybridization, Fluorescence , Leukemia, Myelogenous, Chronic, BCR-ABL Positive/diagnosis , Bone Marrow/pathology , Fluorescent Dyes , Humans , In Situ Hybridization, Fluorescence/instrumentation , In Situ Hybridization, Fluorescence/methods , In Situ Hybridization, Fluorescence/standards , Leukemia, Myelogenous, Chronic, BCR-ABL Positive/genetics , Leukemia, Myelogenous, Chronic, BCR-ABL Positive/pathology , Quality Control , Sensitivity and Specificity , WorkloadABSTRACT
In a series of more than 2,500 fine needle aspirates from multiple body sites, over 200 were clinically identified as lymph nodes from patients with known or suspected malignancy. The material was obtained using the easily manipulated Aspir-Gun with a 21-gauge or 22-gauge needle and syringe. Of the 200 lymph node specimens, 100 (50%) were cytologically reported as positive for malignancy. Ninety cases had surgical pathology specimens available for comparison with the fine needle aspiration (FNA) specimens. For the 88 of these cases with satisfactory FNA specimens, evaluation of the FNA results showed a predictive value of a positive result of 96.8%. These results compare favorably with those of surgical biopsy. The malignancies present in the lymph nodes included numerous adenocarcinomas from the breast, melanoma and pulmonary small-cell carcinoma. Six cases are briefly presented in which the FNA diagnosis was more problematic. While histologic examination of tissues or organs remains the desirable benchmark of comparison, the appropriate utilization of FNA cytology to guide therapy, particularly in a patient with previously diagnosed malignancy, may obviate the need for an open biopsy. The technique is convenient for patient and physician, useful for outpatients, relatively painless and provides good correlation between cytologic morphology and histopathology.
