Objective: To investigate whether the needle washing could yield sufficient cells for tumor marker (TM) measurements as an ancillary technique to ensure the accuracy of fine needle aspiration cytology (FNAC) of tumors.
Study design: After obtaining preliminary data that aspirated tumor cells within a 22-gauge needle could be collected by washing it with distilled water for TM measurements, we studied tumor cell numbers and TM values obtained by washing a 22-gauge needle directly after tumor aspiration and another needle after FNAC.
Results: Using 8 resected hepatobiliary and pancreatic carcinomas, the used needles yielded 16.8+/-10.5 x 10(4) cells per milliliter. Used needles from 6 adenocarcinomas expelled 479.2+/-406.5 ng/mL of carcinoembryonic antigen, and 6,561.3+/-5,713.1 ng/mL of CA 19-9, while the needles from 2 hepatomas showed normal values of those markers.
Conclusion: A needle used for FNAC contains sufficient cells for TM measurements, which can be ancillary to the differential diagnosis.