Thyroid nodules
Demetrius Pertsemlidis, William B. Inabnet III, Michel Gagner in Endocrine Surgery, 2017
FNA biopsy has resulted in substantial improvements in diagnostic accuracy and a higher malignancy yield at time of surgery. FNA biopsy is the most cost-effective and reliable technique available to differentiate between benign and malignant diseases of the thyroid. It is estimated that its use reduces the need for diagnostic thyroidectomy by half and the overall cost of thyroid nodule medical care by one-quarter, while doubling the surgical confirmation of carcinoma. Cytopathologic evaluation has improved significantly over the past two decades, but good aspiration technique and an experienced cytopathologist are necessary to reach the modern high standards. Ultrasound-guided FNA biopsy, combined with on-site cytology verification of the adequacy of the specimen by a cytotechnologist or pathologist, may likely provide the highest sensitivity and specificity. Current sensitivity and specificity generally exceed 90% and 70%, respectively. However, negative cytology results should never override strong clinical suspicion of malignancy. After an initial nondiagnostic cytology result, repeat FNA with ultrasound guidance will yield a diagnostic cytology specimen in 75% of solid nodules and 50% of cystic nodules [16]. For patients who proceed to an operation, prior use of FNA biopsy reduces the need for frozen section analysis for diagnosis, reducing operative time and pathology fees.
Challenges in the Statistical Analysis of Biomarker Data
Anthony P. DeCaprio in Toxicologic Biomarkers, 2006
Tockman et al. (63) examined the use of murine monoclonal antibodies to a glycolipid antigen of human lung cancer as a biomarker in the detection of early lung cancer. As part of their assessment of the interrater reliability of scoring stained specimens, they compared the results obtained on 123 slides read by both a pathologist and a cytotechnologist. The authors stated that they used McNemar’s test to test for “significant agreement (p = 1.000)” between the readers. However, what was actually tested for was a significant difference in classification accuracy between the two readers. While such a test is often informative, one should also measure the degree of agreement between the readers (64). The generally accepted method for assessing agreement between two dichotomous biomarkers, neither of which can be assumed to be the gold standard, is Cohen’s kappa (5). When measuring agreement between three or more dichotomous biomarkers, we recommend the methods described in Shoukri (65).
Cytology of Bladder Cancer
George T. Bryan, Samuel M. Cohen in The Pathology of Bladder Cancer, 2017
A systematic preliminary examination of the cellular sample made by the cytotechnologist is of major importance to the quality of results in urinary tract cytology. The cytotechnologist categorizes the types of cells present. Any significant findings are marked for review by the pathologist. The pathologist must then review the slides and clinical information before completing the report on each sample. This is a specialized area of cytopathology requiring considerable experience by all members of the laboratory staff in order to adequately handle the various diagnostic problems that will occur.
Clinical and ultrasound characteristics distinguishing benign and malignant thyroid nodules in Johannesburg, South Africa
Published in Journal of Endocrinology, Metabolism and Diabetes of South Africa, 2023
Kershlin Naidu, Victoria Saksenberg, Nasrin Goolam Mahyoodeen
Two to six slides were prepared by the operator who performed the FNA using the ‘classic’ smear technique. One slide was air dried, and the remainder of the slides were fixed with Fencott cytological fixative (Sangene Products, Cape Town, South Africa). The cytology slides were stained with a Papanicolaou stain (Merck, Darmstadt, Germany) and were screened by a cytotechnologist using Olympus (CX31) microscopes (Olympus Corp, Shinjuku City, Tokyo, Japan). Adequate specimens contained ≥ 6 groups of well-visualised follicular cells (≥ 10 per cluster), which is consistent with the Bethesda System for Reporting Thyroid Cytopathology.14
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