Sample size in fine needle aspiration biopsy

Abstract

The weights of biopsy specimens from bovine liver taken for fine needle aspiration cytology (FNAC) by three groups of physicians, were compared. The groups differed from each other in their extent or degree of experience in FNAC. When the physicians used their normal technique, the mean sample weight increased significantly with experience, from 4.6 mg in the least experienced group to 17.2 mg in the group with the longest experience. Thirty-six per cent of the samples taken by the group with the least experience were in the weight class 0-2 mg, whereas no such samples were encountered for the other groups. When all the physicians were advised to use the same, standard technique there were no statistically significant differences in mean sample weight between the groups or in the proportion of samples in class 0-2 mg. Sample weights correlated significantly (P less than 0.001) with cell counts. This study shows that differences in the technique of FNAC are responsible for differences in sample weights and cell counts, including the number of the acellular samples obtained. This could explain in some part the wide variation in the reported accuracy rates of FNAC.

Yield and Complications in Ultrasound-Guided Biopsy of Abdominal Lesions

“…The success rate of FNAB has been related to the technique of aspiration, number of passes, type and size of needle, the underlying property of the tissue, and the experience of the operator and cytologist (2, 10, 15,[22][23][24]32). The results of NCB, using an automated gun, seemed to be less dependent on these factors and, provided there are good instructions, an operator with limited experience will perform as well as an experienced one (12).…”

“…The radiologist advanced the needle into the lesion and moved the needle up and down and in different directions with as great an amplitude as possible according to the technique described by KREULA and co-workers (22)(23)(24). Generally 2 to 4 passes were done with FNAB and 1 to 2 with NCB.…”

“…However, the results are variable, depending on the imaging and biopsy technique, operator skill, and the level of cytopathological expertise (3, 10, [22][23][24]29).…”

Ultrasound-guided fine needle aspiration biopsy in the diagnosis of breast cancer recurrence after mastectomy

“…In the present study, unsatisfactory specimens comprised 7.4% of the whole material and included one histologically malignant lesion which was classified as false-negative. A false-negative cytologic finding or inadequate material may be due to a deficient localization or aspiration technique (16,17) or to the characteristics of the lesion. It is known from previous reports that a small lesion size contributes to false-negative FNAB result (9), and that the accuracy of FNAB cytology varies greatly in different carcinomas (9).…”

“…It is known from previous reports that a small lesion size contributes to false-negative FNAB result (9), and that the accuracy of FNAB cytology varies greatly in different carcinomas (9). It is also known that experience minimizes the failure to obtain representative material for a cytologic ex-amination (17,20). The most important cause of false-negative results in the present study was sampling error due to the small size of the target.…”