Rate Of Inadequate Samples Research Articles

Liquid-based cytology in cervical screening: a rapid and systematic review.

Liquid-based cytology in cervical screening: a rapid and systematic review.

Training cytotechnologists to perform papanicolaou smear screening: development and testing of a third world program.

Our objective was (1) to develop a training program for teaching cytotechnology students how to perform Papanicolaou (Pap) smear collection, and (2) to compare the Pap smear adequacy rates of trained cytotechnicians to those of physicians screening the same population. Cytotechnology students received formal lectures about collection and transport of Pap smears and clinical proctoring of Pap smear collection in at least 20 patients. Ten months after completion of training, a review of screening Pap smears collected by all health care professionals over 1 month was performed. Cytopathology review was performed in a blinded fashion. In November 1994, 1,411 screening Pap smears were performed. Patients were seen randomly by generalists, gynecologists, cytotechnicians, or oncologists with collection rates of 991 (70%), 221 (16%), 100 (7%), and 99 (7%) Pap smears, respectively. Inadequate sampling rates (i.e., less than 70% of the slide surface covered with a cell monolayer, endocervical cells present if uterus was in situ, and fewer than 25% of marker cells obscured by blood or inflammatory cells) were: generalists, 8.8%; gynecologists, 9.9%; cytotechnicians, 9.0%; and oncologists, 58.6%. No significant differences were seen in the inadequacy rates of the first three groups, though the oncologists were more likely to perform inadequate Pap smears (p < .01). Third World cytotechnicians can be taught the rudimentary aspects of Pap smear collection, with acceptable rates of inadequate sampling similar to their physician colleagues. Oncologist specialists either should be retrained in the proper collection and processing of Pap smears or should be excluded from this primary care activity.

Breast cytology. Statistical analysis and cytohistologic correlations.

To analyze the sensitivity, specificity, positive and negative predictive values and the efficacy of fine needle aspiration (FNA) in our material, to investigate the influence of the histologic type and stage of carcinoma on the quality of the aspirates and on the detection rates of mammary carcinoma, and to investigate the rate of inadequate samples and the accuracy of cytologic diagnoses, with an emphasis on the rate of false positive diagnoses in benign mammary lesions. The results of 1,472 FNAs of the breast obtained over three years were subjected to a retrospective analysis. The cytologic diagnoses were benign in 1,003 cases (68.1%), suspicious in 49 (3.3%) and malignant in 181 (12.3%); 239 (16.2%) of the aspirates were inadequate. In 393 (26.6%) of the cases and in 85% of cytologically malignant smears, the aspirate was compared with histologic examination. The rate of false negative FNAs was 9.0%. The proportion of inadequate cases was clearly related to stage (pT): it was 9.5% in pT1, 5.0% in pT2 and 0% in pT3. Among invasive carcinomas the sensitivity was 89.9%, specificity 99.3% and overall accuracy 88.5%. Among the cases diagnosed cytologically as benign, 182 were compared with biopsies. Of these, 79.9% were true negative, 0.5% (1 case) was false positive, and 15.4% had insufficient cells for evaluation. FNA cytology has improved decision making and the selection of patients for biopsy of mammary lesions and has contributed to saving time in the clinical management of breast lumps. In no case did FNA lead to inadequate clinical measures or other disadvantages to patients. Thus, FNA cytology is an indispensible diagnostic tool in the management of breast lesions.

Fine needle aspiration (FNA) cytology of the breast: the influence of unsatisfactory samples on patient management.

FNA continues to play an important role in the management of patients with breast lesions. However, the reliability and efficiency of the FNA service depends heavily on the quality of the specimens. We have audited the rate of "inadequate FNAs' at intervals over the last 5 years and related our findings to the clinical expertise of the aspirator. We have also correlated the rate of inadequate FNAs with the percentage of patients who had an FNA preceding a definitive diagnosis of cancer. We report trends in the rate of inadequate samples, and subsequent diagnosis of cancer, over a 5-year period. The percentage of breast FNA samples reported as inadequate was 46.8% in 1988-89, falling to 20% in 1991-92 with the introduction of an FNA clinic, and rising to 30.6% in 1993. The rates of cancer following inadequate FNA were 15.7%, 16.1% and 4.2%, respectively, and the percentage of patients with cancer having a preceding inadequate FNA were 37.5%, 13.2% and 7.1%. Possible explanations for the apparent paradox between increasing numbers of inadequate FNA specimens and a falling breast cancer rate are discussed.

96/03638 Separation of Fischer-Tropsch catalyst/wax mixtures using dense-gas and liquid extraction

Prophylactic human papillomavirus (HPV) vaccines are recommended for prevention of HPV-associated cancers. Type-specific detection of HPV in formalin-fixed, paraffin-embedded (FFPE) tissues retrieved from diagnostic pathology laboratories is important in monitoring the impact of HPV vaccines. However, few typing assays have been validated for testing FFPE samples. Results of the Novaplex II HPV28 Detection (Novaplex) assay were compared with those from the reference assay (Linear Array with reflex Line Probe Assay) on 708 FFPE samples from cervical lesions. Novaplex showed high type-specific concordance with the reference method for HPV16/18, 9 types targeted by the Gardasil 9 vaccine, 14 high-risk types, and 21 types covered by comparison assays. The rate of inadequate samples was low in both approaches (reference, 3.4%; Novaplex, 1.7%). The proportion of discrepant types was less than 3.5% and positive concordance was greater than 75.0%. Furthermore, the type-specific positive agreement (92.0% to 98.0%), negative agreement (96.0% to 99.0%), and accuracy (97.0% to 99.0%) was high. Cohen's κ ranged from 0.86 to 0.89, indicating excellent agreement between Novaplex and reference assays. The results show that Novaplex is a suitable method for detection of HPV in FFPE tissues.

Nondiagnostic fine needle aspiration biopsy of the thyroid gland: a diagnostic dilemma.

To evaluate all nondiagnostic fine needle aspiration biopsy (FNAB) specimens from the thyroid gland with subsequent histopathologic diagnoses at Ottawa Civic Hospital. The criterion for specimen adequacy used in our institution was also reexamined to determine if it was too stringent. Review of 114 nondiagnostic FNAB samples from 91 patients with subsequent histopathologic diagnoses formed the basis of this study. Specimen adequacy was determined by the presence of 8-10 fragments of well-preserved follicular cells on at least two smears. Review of the 91 surgical specimens found 50 nodular goiters, 23 follicular adenomas, 6 macrofollicular adenomas, 5 cases of thyroiditis, 5 true cysts, 1 papillary carcinoma and 1 minimally invasive follicular carcinoma. Forty-two percent of lesions showed cystic change. In addition, nine cases of papillary microcarcinoma were diagnosed. A considerable difference in the rate (22% vs. 45%) of inadequate thyroid FNAB samples was identified among different groups of physicians at our institution. Ninety-eight percent of the patients with nondiagnostic FNAB of the thyroid gland had benign lesions. This finding encouraged us to continue using our criteria for adequacy because of the importance of a negative report. The higher rate of nondiagnostic thyroid aspiration in our series may reflect the varied experience of the different aspirators at our institution and/or the cystic nature of many of the lesions.

Fine‐needle cytology of the breast: A controlled study of aspiration versus nonaspiration

We report on 534 breast masses examined by fine-needle aspiration cytology. Two samples were obtained from each mass, one with aspiration and the other without. Aspiration, equivalent to that obtained by a 20-ml syringe on full aspiration, was obtained by an automatic aspirator. The two sampling modalities did not differ apart from aspiration and were compared in terms of inadequate sampling rates. The inadequacy rate was the same in 166 cancers (6.6%), whereas a significant difference was recorded in favor of aspiration (13.6 versus 24.4%) in 368 benign masses. When inadequate results were excluded, the accuracy of the two modalities was almost the same. Sensitivity was 97.4% and 96.7% and specificity was 99.4% and 99.3% for sampling with and without aspiration, respectively. Reducing the rate of inadequate sampling from benign masses seems to be the major advantage of aspiration. Double sampling, independent of the specific techniques, reduced inadequacy rates to very low levels (1.2% for cancers; 5.9% for benign masses) and may be useful as a routine policy.

Discrete sampling of continuous biological signals: Analog-to-digital conversion

Computer processing of many electrophysiological events requires analog-to-digital conversion (ADC) of the time-varying signal. Inadequate ADC sampling rates affect the accuracy of amplitude and latency measurements and introduce rate-limited errors. A second class of errors, termed limited-precision errors, result from the limitation imposed by the word size (in bits) of the ADC. Total error is the sum of rate-limited error and limited-precision error, but can be controlled and specified as described here. Given the critical nature of ADC parameters, a standard is proposed for describing ADC performance.

The present state of digital vocoding technique: A diagnostic evaluation

Eight state-of-the-art pitch-excited digital vocoders (2400 bits/s) were evaluated with the Diagnostic Rhyme Test, a two-choice test of the discriminability of six elementary attributes of consonant phonemes. All of the systems tested performed adequately with respect to the attributes, voicing, nasality, sibilation, and compactness. None, however, permitted adequate discrimination of the attributes, sustention (friction versus plosion) and graveness. All systems reduced the gross discriminability of these attributes and significantly biased listeners perception of the states of one or both. It is hypothesized that these deficiencies stem primarily from inadequate spectrum sampling rate (i.e., frame rate) rather than inadequate "spectrum resolution."