The key to an adequate aspiration is the immobilization of the mass by the aspirator's free hand. The needle, with syringe and holder attached, is then inserted into the mass. The syringe plunger is pulled back as the needle is advanced forward and backward. Excessive directional changes result in increased bleeding and inadequate specimens. Within seconds, a blood-tinged specimen appears in the hub of the needle.
Suction is released and the needle is withdrawn.
The syringe is detached from the needle, filled with air, and then reattached. The aspirator expresses a drop of the specimen onto one or more slides. This drop is smeared in much the same way as a peripheral blood smear and is either fixed with ethanol or air dried, according to the interpreting pathologist's preference. Next, the slides are ready for staining and interpretation. Acquisition to interpretation can take as little as 15 minutes.