CYTOLOGIC ANALYSIS IN FINE-NEEDLE ASPIRATION BIOPSY - SMEARS VS CELL BLOCKS

OBJECTIVE. Imaging-directed fine-needle aspiration biopsy can be perfo rmed with or without immediate cytologic assessment (smears). We compa red the results obtained immediately from cytologic smears with the re sults of cell-block analysis. We wished to determine the frequency of false-negative findings on cytologic smears in patients subsequently f ound to have malignant tumors by cell-block analysis. MATERIALS AND ME THODS. We retrospectively reviewed the records for 100 consecutive bio psies performed between January 1986 and August 1987. In each case, sp ecimens were obtained from both a 22-gauge and a 20-gauge notched need le placed in tandem. The study group consisted of 84 patients who had results of analyses of both cytologic smears and cell blocks available for review and who had clinical or surgical correlation. RESULTS. Six ty-four (76%) of the 84 biopsies yielded malignant tumor cells, 11 yie lded evidence of a benign process, and nine were not diagnostic. Malig nant tumor cells were seen on the cytologic smears in 55 (86%) of the 64 patients who had malignant tumors; in the other nine patients, the malignant tumors were indicated by the cell-block analysis only. Withi n the group of benign disorders, in only one case (9%) was the cell bl ock diagnostic when the cytologic smear was not. CONCLUSION. Operators performing fine-needle aspiration biopsy should be aware of the limit ations of immediate cytologic evaluation. Cell-block analysis of the a spirate remaining after the smears are made can be expected to increas e the diagnostic accuracy in up to 14% of patients.